Entity

Time filter

Source Type

Uppsala, Sweden

The Swedish University of Agricultural science is a university in Sweden. Although its head office is located in Ultuna, Uppsala, the university has several campuses in different parts of Sweden, the other main facilities being Alnarp in Lomma Municipality, Skara, and Umeå. Unlike other state owned universities in Sweden, it is funded through the budget for the Ministry for Rural Affairs.The university has four faculties: Faculty of Landscape Planning, Horticulture and Agricultural science, Faculty of Natural Resources and Agriculture science, Faculty of Veterinary Medicine and Animal Science and Faculty of Forest science. SLU had in 2012 3080 full-time staff, 3935 full-time students, 714 research students and 241 professors.In the 2007 Academic Ranking of World Universities, SLU was ranked in 5-9 place in Sweden, 81-123 in Europe and 203-304 in the world. Wikipedia.


Curstedt T.,Karolinska University Hospital | Johansson J.,Swedish University of Agricultural Sciences
Neonatology | Year: 2010

Treatment of premature newborn rabbits with synthetic surfactants containing a surfactant protein C analogue in a simple phospholipid mixture gives similar tidal volumes as treatment with poractant alfa (Curosurf®) but ventilation with a positive end-expiratory pressure (PEEP) is needed for this synthetic surfactant to stabilize the alveoli at end-expiration. The effect on lung gas volumes seems to depend on the structure of the peptide since treatment with a synthetic surfactant containing the 21-residue peptide (LysLeu 4)4Lys (KL4) gives low lung gas volumes in experiments also performed with PEEP. Surfactant preparations containing both surfactant proteins B and C or their analogues prevent alveolar collapse at end-expiration even if ventilated without PEEP. Treatment of premature newborn rabbits with different natural surfactants indicates that both the lipid composition and the proteins are important in order to stabilize the alveoli at end-expiration. Synthetic surfactants containing two peptides may be able to replace natural surfactants within the near future but more trials need to be performed before any conclusion can be drawn about the ideal composition of this new generation of synthetic surfactants. © 2010 S. Karger AG, Basel.


Orians C.M.,Tufts University | Hochwender C.G.,University of Evansville | Fritz R.S.,Vassar College | Snall T.,Swedish University of Agricultural Sciences
Oecologia | Year: 2010

Many studies have failed to detect costs of defense and some have even found a positive correlation between growth and the concentrations of chemical defenses. These studies contradict the theoretical assumption that anti-herbivore defenses are costly-produced at the expense of growth and/or reproduction. Costs, however, may be transient and therefore difficult to detect. Here we tested the hypothesis that costs of defense would be pronounced early in development when root growth is prioritized (high percent root allocation), but not later in development. To test this hypothesis, we grew F 2 hybrid willow seedlings from five different families, and harvested cohorts of even-aged seedlings after 6, 7, 8 and 9 weeks of growth. Seedlings were divided into root and shoot tissue and shoots were analyzed for phenolics (condensed tannins and phenolic glycosides). We found evidence for transient costs of defense. The concentrations of phenolics were negatively correlated with total biomass, shoot biomass, and the proportion of biomass allocated to roots in week 6. After week 6, however, the concentrations of phenolics were positively correlated with shoot biomass and total biomass, while phenolics were uncorrelated with the proportion of biomass allocated to roots. These results, the first ever, to our knowledge, with woody plants, suggest that costs of defense were transient; specifically, costs were found in early development, when root establishment was a priority. Our findings suggest that studies should focus more on trade-offs early in plant development. © 2009 Springer-Verlag.


Balkenius A.,Swedish University of Agricultural Sciences | Hansson B.,Max Planck Institute for Chemical Ecology
PLoS ONE | Year: 2012

Background: The mushroom bodies of the insect brain play an important role in olfactory processing, associative learning and memory. The mushroom bodies show odor-specific spatial patterns of activity and are also influenced by visual stimuli. Methodology/Principal Findings: Functional imaging was used to investigate changes in the in vivo responses of the mushroom body of the hawkmoth Manduca sexta during multimodal discrimination training. A visual and an odour stimulus were presented either together or individually. Initially, mushroom body activation patterns were identical to the odour stimulus and the multimodal stimulus. After training, however, the mushroom body response to the rewarded multimodal stimulus was significantly lower than the response to the unrewarded unimodal odour stimulus, indicating that the coding of the stimuli had changed as a result of training. The opposite pattern was seen when only the unimodal odour stimulus was rewarded. In this case, the mushroom body was more strongly activated by the multimodal stimuli after training. When no stimuli were rewarded, the mushroom body activity decreased for both the multimodal and unimodal odour stimuli. There was no measurable response to the unimodal visual stimulus in any of the experiments. These results can be explained using a connectionist model where the mushroom body is assumed to be excited by olfactory stimulus components, and suppressed by multimodal configurations. Conclusions: Discrimination training with multimodal stimuli consisting of visual and odour cues leads to stimulus specific changes in the in vivo responses of the mushroom body of the hawkmoth. © 2012 Balkenius, Hansson.


Manevska-Tasevska G.,Swedish University of Agricultural Sciences
Journal of Agricultural Education and Extension | Year: 2013

Purpose: This study sought to explore how farmers' knowledge attributes influence the technical efficiency of their farms. In addition, farm efficiency was compared to the actual Macedonian Rural Development Programme (RDP) (2007-2013) and instruments considered to improve Macedonian education potential were evaluated.Design/methodology/approach: The three-year (2006-2008) panel data set on Macedonian grape-producing family farms were analysed. A two-stage approach for efficiency analysis was used. In the first stage, technical efficiency scores were estimated using a parametric Stochastic Frontier approach. In the second stage regression, the impact of farmers' knowledge attributes on farm efficiency was assessed.Findings: The results suggest that farmers' knowledge attributes have the potential to influence farm economic performance. Non-formal knowledge sources, such as seminars, and competence-based learning appeared to be key to achieving higher technical efficiency. Within the instruments used for strengthening the knowledge potential of Macedonian farmers, supporting non-formal education and young farmers' enrolment in agricultural production should remain priorities.Practical implications: As the study relates to specific RDP instruments, it is of practical importance for policy-makers and knowledge-providing systems.Originality/value: The study is of value in explaining the knowledge potential of farmers working in transition economies and its importance for attaining higher efficiency. Despite the evidence on the importance of knowledge in strengthening farm performance, the influence of educational practices and potential knowledge attributes on farm efficiency has not previously been analysed in the context of an economy in transition. © 2013 Copyright Wageningen University.


Viketoft M.,Swedish University of Agricultural Sciences
Soil Biology and Biochemistry | Year: 2013

Belowground communities support a great diversity of organisms, but the factors that maintain and regulate this diversity are poorly understood. Both abiotic and biotic factors affect the abundance, diversity and distribution of soil organisms, and the spatial heterogeneity in these factors is a key in explaining belowground biodiversity. However, a combined approach estimating the relative importance of spatial and environmental factors in small-scale structuring of soil communities is yet missing. Here, a semi-natural grassland in south-central Sweden with high diversity of plants was sampled at two spatial scales (10 and 60cm intervals) with the aim to examine the relative roles of plant identity, abiotic environmental factors and spatial factors for the small-scale spatial patterns of nematodes. The data were analysed by variance partitioning with redundancy analysis. Space, vegetation and abiotics were of similar importance for variation in nematode community composition. However, the contribution of the different sets of variables differed between the different nematode feeding groups: plant-feeding nematodes were influenced more by spatial variables, fungal-feeding nematodes and omnivores/predators more by plants and bacterial-feeding nematodes more by abiotic variables. The ranges of spatial dependence for the different feeding groups were all of the same magnitude, around 1m. The results add to the understanding of the factors that contribute to soil biodiversity, and they show that combining plant and abiotic variables into one set of environmental variables hide important information about the drivers for belowground community assembly. © 2013 Elsevier Ltd.


Low M.,Swedish University of Agricultural Sciences
New Zealand Journal of Ecology | Year: 2010

Reintroduction programmes need to be monitored as a way of gauging potential causes of their success or failure. This, in turn, can be used to improve the likelihood of future translocation success. Since the 1990s, stitchbird (or hihi: Notiomystis cincta) translocations have been intensively monitored, with comparisons between two of these projects (Tiritiri Matangi Island - a successful introduction, and Mokoia Island - an unsuccessful introduction) often compared and contrasted as a means of identifying factors important in translocation success for this species. A consistently low adult survival rate on Mokoia Island in conjunction with a study showing a high prevalence of aspergillosis (a fungal disease of the respiratory tract caused by Aspergillus fumigatus) in adult stitchbirds led to this disease being commonly discussed as a major factor responsible for the difference in translocation outcomes. However, A. fumigatus infection rates have never been compared between the two stitchbird populations; thus, population differences in adult survival may have resulted from other factors. One possibility is that survival differences between populations were influenced by differing predation pressures from morepork (or ruru: Ninox novaeseelandiae). Evidence of stitchbird predation by moreporks and the fact that morepork density on Mokoia Island was markedly higher than on Tiritiri Matangi Island provides some support for this hypothesis. It is important that all plausible hypotheses for differences in survival be considered so that we can better evaluate future conservation strategies that target the recovery of this species. © New Zealand Ecological Society.


Elofsson K.,Swedish University of Agricultural Sciences
Marine Policy | Year: 2010

The governments around the Baltic Sea have agreed on a new set of targets for nutrient load reductions. The major motive for this is new and better knowledge about the link between nutrient loads and water transparency in different parts of the sea. The Baltic Sea Action Plan (BSAP) defines target for transparency in different marine basins, the load reductions necessary to meet transparency targets and a scheme for the distribution of the abatement burden between countries adjacent to the sea.Using a spatially disaggregated cost-effectiveness model, this paper analyzes the environmental effects of a cost-effective policy for meeting BSAP targets under joint costs of reducing nitrogen and phosphorus loads. The marginal cost of nutrient reductions to different parts of the Baltic Sea is derived and the potential cost savings from basin-wide nutrient load permit trade are investigated.The results show that cost-effective fulfillment of BSAP's load targets can imply that water transparency is improved beyond the target levels due to joint reductions of nitrogen and phosphorus. This suggests that costs could be saved through an adjustment of the basin-wise load reduction targets, while still meeting targets for water transparency. The analysis shows that well-functioning load permit trade can reduce the total annual cost of meeting the BSAP's basin targets by 16%, corresponding to 724 million € per year. © 2010 Elsevier Ltd.


Honkanen M.,University of Jyvaskyla | Roberge J.-M.,University of Jyvaskyla | Roberge J.-M.,Swedish University of Agricultural Sciences | Rajasarkka A.,Metsahallitus | Monkkonen M.,University of Jyvaskyla
Global Ecology and Biogeography | Year: 2010

Aim: One of the few general laws in ecology is that species richness is a positive function of area. However, it has been proposed that area would merely be a proxy for energy. Additionally, habitat heterogeneity has been found to be an important factor determining species richness. Yet the relative importance of those relationships is little known, and it is still unclear how they are brought about. We aimed to dissect which factors drive the species richness of boreal forest birds, and to identify the most probable mechanisms. Location: Forested protected areas in Finland. Methods: Using bird line census data collected in 104 protected areas, we ran simultaneous autoregressive models to explain the species richness of forest birds. We explored the value of forest area, tree volume, tree growth, mean degree days and habitat heterogeneity as explanatory variables and used the species richness within different species groups, based on the predictions of hypothesized mechanisms, as a response variable. Results: Energy, rather than area or habitat heterogeneity, seems to be the main driver of species richness in boreal forest birds. More specifically, productive energy was a better predictor of total species richness than solar energy. Among the tested hypothetical mechanisms, the sampling hypothesis received strong support. After accounting for sampling, solar energy had an effect on species richness. Main conclusions: As productive energy, such as tree volume, is associated with species richness, high-energy areas should be prioritized in forest conservation planning. Reductions in productive energy may first lead to the disappearance of the rarest species due to the random sampling process. Climate change may result in increased species richness due to increasing amount of productive and solar energy in forests. However, the range shifts of bird species may not be fast enough to keep up with the temperature increases. © 2009 Blackwell Publishing Ltd.


Brukas V.,Swedish University of Agricultural Sciences
Journal of Environmental Policy and Planning | Year: 2015

Abstract: Radical socio-economic transition has brought significant yet vaguely understood challenges for forestry in the countries of the former Eastern Bloc. This study narrates the case of the Lithuanian forestry transition, structured along the divides of actor versus structure and material versus ideational world. The narrative exposes remarkably stable forest policy with a significant exception of increased environmental consideration, induced mainly by strong external pressures. The forest policy arena is dominated by state authorities that are grounded in the theory of normal forest, rather distrust private forestry and primarily rely on regulatory instruments. Though the prevailing forestry paradigm has been challenged by researchers, arguing for administrative reforms, increased economic efficiency and larger decision freedom, the alternative ideas were either neglected or denounced fiercely. Such conservatism is a combined effect of ideological heritage of the forestry profession intermingled with vested interests by state forestry authorities. © 2015 Taylor & Francis.


Allen M.L.,U.S. Department of Agriculture | Walker W.B.,U.S. Department of Agriculture | Walker W.B.,Swedish University of Agricultural Sciences
Journal of Insect Physiology | Year: 2012

The prospects for development of highly specific pesticides based on double stranded ribonucleic acid have been a recent focus of scientific research. Creative applications have been proposed and demonstrated. However, not all insects are sensitive to double stranded RNA (dsRNA) gene knockdown effects; applications in the order Lepidoptera, for example, have met with varied success. Gene knockdown has been demonstrated in several species in the order Hemiptera. In our laboratory, knockdown experiments relied on microinjection of dsRNA into the hemocoel of the tarnished plant bug, Lygus lineolaris. Subsequent experiments delivering dsRNA to insects by feeding were repeatedly unsuccessful in demonstrating knockdown, and a hypothesis was formulated that the dsRNA was digested and degraded by the insect prior to contact with the insect cells. Exposure of dsRNA to insect saliva, insect salivary glands, and insect hemolymph was compared with commercial RNAase III. The saliva of L. lineolaris was found to rapidly digest double stranded RNA. RNAase inhibitor did not affect the activity but heat treatment slowed enzymatic activity. © 2011.


Trona F.,Swedish University of Agricultural Sciences
Proceedings. Biological sciences / The Royal Society | Year: 2013

Understanding the processing of odour mixtures is a focus in olfaction research. Through a neuroethological approach, we demonstrate that different odour types, sex and habitat cues are coded together in an insect herbivore. Stronger flight attraction of codling moth males, Cydia pomonella, to blends of female sex pheromone and plant odour, compared with single compounds, was corroborated by functional imaging of the olfactory centres in the insect brain, the antennal lobes (ALs). The macroglomerular complex (MGC) in the AL, which is dedicated to pheromone perception, showed an enhanced response to blends of pheromone and plant signals, whereas the response in glomeruli surrounding the MGC was suppressed. Intracellular recordings from AL projection neurons that transmit odour information to higher brain centres, confirmed this synergistic interaction in the MGC. These findings underscore that, in nature, sex pheromone and plant odours are perceived as an ensemble. That mating and habitat cues are coded as blends in the MGC of the AL highlights the dual role of plant signals in habitat selection and in premating sexual communication. It suggests that the MGC is a common target for sexual and natural selection in moths, facilitating ecological speciation.


Mason N.W.H.,Landcare Research | Richardson S.J.,Landcare Research | Peltzer D.A.,Landcare Research | de Bello F.,Academy of Sciences of the Czech Republic | And 3 more authors.
Journal of Ecology | Year: 2012

Functional trait diversity can reveal mechanisms of species coexistence in plant communities. Few studies have tested whether functional diversity for foliar traits related to resource-use strategy increases or decreases with declining soil phosphorus (P) in forest communities. We quantified tree basal area and four foliar functional traits (i.e. nitrogen (N), phosphorus (P), thickness and tissue density) for all woody species along the c.120000year Franz Josef soil chronosequence in cool temperate rain forest, where strong shifts occur in light and soil nutrient availability (i.e. total soil P declines from 805 to 100mgkg -1). We combined the abundance and trait data in functional diversity indices to quantify trait convergence and divergence, in an effort to determine whether mechanisms of coexistence change with soil fertility. Relationships between species trait means and total soil N and P were examined using multiple regression, with and without weighting of species abundances. We used Rao's quadratic entropy to quantify functional diversity at the plot scale, then compared this with random expectation, using a null model that randomizes abundances across species within plots. Taxonomic diversity was measured using Simpson's Diversity. Relationships between functional and taxonomic diversity and total soil P were examined using jackknife linear regression. Leaf N and P declined and leaf thickness and density increased monotonically with declining total soil P along the sequence; these relationships were unaffected by abundance weighting of species in the analyses. Inclusion of total soil N did not improve predictions of trait means. All measures of diversity calculated from presence/absence data were unrelated to total soil N and P. There was no evidence for a relationship between Rao values using quantitative abundances and total soil P. However, there was a strong positive relationship between Rao, expressed relative to random expectation, and total soil P, indicating trait convergence of dominant species as soil P declined. Synthesis: Our results demonstrate that at high fertility locally dominant species differ in resource-use strategy, but as soil fertility declines over the long term, dominant species increasingly converge on a resource-retentive strategy. This suggests that differentiation in resource-use strategy is required for coexistence at high-fertility but not in low-fertility ecosystems. © 2012 The Authors. Journal of Ecology © 2012 British Ecological Society.


Sundh I.,Swedish University of Agricultural Sciences | Goettel M.S.,Agriculture and Agri Food Canada
BioControl | Year: 2013

Ever since the inclusion of microbial biocontrol agents (MBCAs) within the regulatory frameworks initially designed for chemical pesticides, there has been awareness that these frameworks are not optimal for assessment and registration of new microbial biocontrol products. It is often claimed that the regulatory situation has contributed to a relatively slow uptake of microbial biocontrol in practice. In contrast to the MBCAs, non-indigenous invertebrate biocontrol agents (IBCAs) are regulated in many countries through quarantine and other biosecurity related legislation for prevention of introduction of alien organisms, whereas use of indigenous IBCAs are generally unregulated. In this study, we investigate what scientific support there is for performing evaluations of these two main groups of biocontrol agents (BCAs) within different frameworks. We compare potential risks of MBCAs and IBCAs, present a retrospective analysis of the development and implementation of the regulatory frameworks, and compare current requirements for MBCAs with those for other applications with microorganisms. One conclusion is that the ecological risks are of similar types between the two groups of BCAs, and that for both groups the environmental safety is most pertinently evaluated according to biological and ecological principles. The main difference between MBCAs and IBCAs with respect to human health is that the former may cause infectious disease. However, we found no evidence that this hazard is more serious for microorganisms for biocontrol than for microbes used in other types of applications, which generally have substantially lower regulatory demands than those for MBCAs. Several international initiatives have produced helpful guidelines and recommendations for simplified assessments and authorisations of BCAs. Still, we conclude that as long as MBCAs are evaluated within systems initially developed for chemicals, the risk for inappropriate emphasis of chemical hazards and therefore unnecessarily complicated assessments will be maintained. Therefore, this study supports the idea that development of new systems for the regulatory oversight of MBCAs, possibly a mutual framework covering all living BCAs, should be considered. Research issues that need to be further explored are to what extent utilisation of MBCAs actually results in increased exposure of non-targets to microorganisms, the biogeography and microbial ecology of representative MBCAs, and finally development of better methodology for determining potential human toxicity and pathogenicity of candidate MBCAs. © 2012 International Organization for Biological Control (IOBC).


Schrumpf M.,Max Planck Institute for Biogeochemistry | Kaiser K.,Martin Luther University of Halle Wittenberg | Guggenberger G.,Leibniz University of Hanover | Persson T.,Swedish University of Agricultural Sciences | And 2 more authors.
Biogeosciences | Year: 2013

Conceptual models suggest that stability of organic carbon (OC) in soil depends on the source of plant litter, occlusion within aggregates, incorporation in organomineral complexes, and location within the soil profile. Density fractionation is a useful tool to study the relevance of OC stabilization in aggregates and in association with minerals, but it has rarely been applied to full soil profiles. We aim to determine factors shaping the depth profiles of physically unprotected and mineral associated OC and test their relevance for OC stability across a range of European soils that vary in vegetation, soil types, parent material, and land use. At each of the 12 study sites, 10 soil cores were sampled to 60 cm depth and subjected to density separation. Bulk soil samples and density fractions (free light fractions - fLF, occluded light fractions - oLF, heavy fractions - HF) were analysed for OC, total nitrogen (TN), δ13C, and Δ14C Bulk samples were also incubated to determine CO2 evolution per g OC in the samples (specific mineralization rates) as an indicator for OC stability. Depth profiles of OC in the light fraction (LF-OC) matched those of roots for undisturbed grassland and forest sites, suggesting that roots are shaping the depth distribution of LF-OC. Organic C in the HF declined less with soil depth than LF-OC and roots, especially at grassland sites. The decrease in Δ14C (increase in age) of HF-OC with soil depth was related to soil pH as well as to dissolved OC fluxes. This indicates that dissolved OC translocation contributes to the formation of subsoil HF-OC and shapes the Δ14C profiles. The LF at three sites were rather depleted in 14C, indicating the presence of fossil material such as coal and lignite, probably inherited from the parent material. At the other sites, modern Δ14C signatures and pos sit tive correlations between specific mineralization rates and fLF-OC indicate the fLF is a potentially available energy and nutrient source for subsurface microorganisms throughout the profile. Declining specific mineralization rates with soil depth confirm greater stability of OC in subsoils across sites. The overall importance of OC stabilization by binding to minerals was demonstrated by declining specific mineralization rates with increasing contributions of HF-OC to bulk soil OC, and the low Δ14C values of HF-OC. The stability of HF-OC was greater in subsoils than in topsoils; nevertheless, a portion of HF-OC was active throughout the profile. While quantitatively less important than OC in the HF, consistent older ages of oLF-OC than fLF-OC suggest that occlusion of LF-OC in aggregates also contributes to OC stability in subsoils. Overall, our results indicate that association with minerals is the most important factor in stabilization of OC in soils, irrespective of vegetation, soil type, and land use. © Author(s) 2013.


Johansson T.,Swedish University of Agricultural Sciences
Journal of Forestry Research | Year: 2013

In this study height growth models for hybrid aspen were developed using three growth equations. The mean age of the hybrid aspen was 21 years (range 15-51 years) with a mean stand density of 946 stems ha-1 (87-2374) and a mean diameter at breast height (over bark) of 19.6 cm (8.5-40.8 cm). Site index was also examined in relation to soil type. Multiple samples were collected for three types of soil: light clay, medium clay and till. Site index curves were constructed using the collected data and compared with published reports. A number of dynamic equations were assessed for modeling top-height growth from total age. A Generalized Algebraic Difference Approach model derived by Cieszewski (2001) performed the best. This model explained 99% of the observed variation in tree height growth and exhibited no apparent bias across the range of predicted site indices. There were no significant differences between the soil types and site indices. © 2013 Northeast Forestry University and Springer-Verlag Berlin Heidelberg.


Wastfelt A.,Swedish University of Agricultural Sciences | Arnberg W.,University of Stockholm
International Journal of Applied Earth Observation and Geoinformation | Year: 2013

Research making use of satellite data for land change science has developed in the last decades. However, analysis of land use has not developed with the same speed as development of new satellite sensors and available land cover data. Improvement of land use analysis is possible, but more advanced methods are needed which make it possible to link image data to analysis of land use functions. To make this linking possible, variable which affect farmer's long term decisions must be taken into account in analysis as well as the relative importance of the landscape itself. A GIS-based tool for the measurement of local spatial context in satellite data is presented in this paper and used to explore the relationship between land covers present in satellite data and land use represented in official databases. By the use of the developed tool, a land configuration image (LCI) over the Siljan area in northern Sweden was produced and used for analysis. The results are twofold. First, the produced LCI holds new information about variables that are relevant for the interpretation of land use. Second, the comparison with statistics of agricultural production shows that production in the study area varies depending on the relative land configuration. Villages consisting of relatively largescale arable fields and less diverse landscape are less diverse in production than villages which consist of smaller-scale and more heterogonous landscapes. The result is especially relevant for land use studies and policymakers working on environmental and agricultural policies. We conclude that local spatial context is an endogenous variable in the relation between landscape configuration and agricultural land use. © 2012 Elsevier B.V.


Sundberg S.,Uppsala University | Sundberg S.,Swedish University of Agricultural Sciences
Ecography | Year: 2013

While patterns of spore dispersal from single sources at short distances are fairly well known, information about 'spore rain' from numerous sources and at larger spatial scales is generally lacking. In this study, I sampled spore rain using a novel method consisting of 0.25-0.5 m2 cotton cloth traps at nine sites in the boreo-nemoral vegetation zone in eastern Sweden during two seasons, using Sphagnum spores as a model. Traps were located in various landscapes (mainland, islands). Additional trapping was done in an arctic area (Svalbard) without spore production. Spore densities were tested against distance from the nearest source and area of sources (open peatlands) within different radii around each site (5, 10, 20, 50, 100, 200, 300, 400 km). The cloth method appeared reliable when accounting for precipitation losses, retaining approximately 20-60% of the spores under the recorded amounts of precipitation. Estimated spore densities ranged from 6 million m-2 and season within a large area source, via regional deposition of 50 000-240 000 spores m-2, down to 1000 m-2 at Svalbard. Spore rain for all sites was strongly related to distance from the nearest source, but when excluding samples taken within a source peatland, the amount of sources within 200 km was most important. Spores were larger at isolated island sites, indicating that a higher proportion originated from distant, humid areas. Immense amounts of Sphagnum spores are dispersed across regional distances annually in boreal areas, explaining the success of the genus to colonise nutrient poor wetlands. The detectable deposition at Svalbard indicates that about 1% of the regional spore rain has a trans- or intercontinental origin. The regional spore rain, originating from numerous sources in the landscape, is probably valid for most organisms with small diaspores and provides a useful insight in ecology, habitat restoration and conservation planning. © 2012 The Authors.


Jensen E.S.,Swedish University of Agricultural Sciences | Peoples M.B.,CSIRO | Hauggaard-Nielsen H.,Technical University of Denmark
Field Crops Research | Year: 2010

The grain legume (pulse) faba bean (Vicia faba L.) is grown world-wide as a protein source for food and feed. At the same time faba bean offers ecosystem services such as renewable inputs of nitrogen (N) into crops and soil via biological N2 fixation, and a diversification of cropping systems. Even though the global average grain yield has almost doubled during the past 50 years the total area sown to faba beans has declined by 56% over the same period. The season-to-season fluctuations in grain yield of faba bean and the progressive replacement of traditional farming systems, which utilized legumes to provide N to maintain soil N fertility, with industrialized, largely cereal-based systems that are heavily reliant upon fossil fuels (=N fertilizers, heavy mechanization) are some of the explanations for this decline in importance. Past studies of faba bean in cropping systems have tended to focus on the effect of faba bean as a pre-crop in mainly cereal intensive rotations, whereas similar information on the effect of preceding crops on faba bean is lacking. Faba bean has the highest average reliance on N2 fixation for growth of the major cool season grain legumes. As a consequence the N benefit for following crops is often high, and several studies have demonstrated substantial savings (up to 100-200 kg N ha-1) in the amount of N fertilizer required to maximize the yield of crops grown after faba bean. There is, however, a requirement to evaluate the potential risks of losses of N from the plant-soil system associated with faba bean cropping via nitrate leaching or emissions of N2O to the atmosphere as a consequence of the rapid mineralization of N from its N-rich residues. It is important to develop improved preventive measures, such as catch crops, intercropping, or no-till technologies, in order to provide farmers with strategies to minimize any possible undesirable effects on the environment that might result from their inclusion of faba bean in cropping system. This needs to be combined with research that can lead to a reduction in the current extent of yield variability, so that faba bean may prove to be a key component of future arable cropping systems where declining supplies and high prices of fossil energy are likely to constrain the affordability and use of fertilizers. This will help address the increasing demand by consumers and governments for agriculture to reduce its impact on the environment and climate through new, more sustainable approaches to food production. The aims of this paper are to review the role of faba bean in global plant production systems, the requirements for optimal faba bean production and to highlight the beneficial effects of faba bean in cropping systems. © 2009 Elsevier B.V. All rights reserved.


During the last decades of the 19th century, a great worry arose about forest landscape paludification in Northern Sweden. This was the original impetus for forest hydrological research in Sweden, and the Swedish Institute of Experimental Forestry established the first field research site in 1905 at Rokliden, close to Piteå in North Sweden. It comprised 8.64ha located 2km down a 3-km-long gently sloping (~4%), north facing Norway spruce covered till slope, interspersed with small mires. By 1931, it was concluded that paludification was not spreading across Northern Sweden at an appreciable rate. Within the Rokliden research site, 22 groundwater wells were installed and levels measured weekly until 1926. A map with 0.5m equidistance, ten vegetation classes, and soil profiles was established. Groundwater flow velocity was estimated by tracing added sodium chloride. Hydraulic conductivity was measured on undisturbed soil cores, while mechanical and chemical analyses were carried out on other samples. Groundwater was collected and analysed for dissolved compounds including oxygen. Hydrology was found important for soil types and vegetation development. The necessary profile drainage for podzol soil development was identified as vein drainage at the bedrock surface. Modern measurements in the re-established groundwater observation network and re-analysis of old data confirmed the plausibility of these original conclusions. Partial catchment area could explain rates of both groundwater level rise and recession. Revisiting this field study reveals that many issues in contemporary hillslope hydrology were already established a century ago, even though the provenance of that knowledge is not generally recognized. © 2014 John Wiley & Sons, Ltd.


Lindahl B.D.,Swedish University of Agricultural Sciences | Tunlid A.,Lund University
New Phytologist | Year: 2015

Although hypothesized for many years, the involvement of ectomycorrhizal fungi in decomposition of soil organic matter remains controversial and has not yet been fully acknowledged as an important factor in the regulation of soil carbon (C) storage. Here, we review recent findings, which support the view that some ectomycorrhizal fungi have the capacity to oxidize organic matter, either by 'brown-rot' Fenton chemistry or using 'white-rot' peroxidases. We propose that ectomycorrhizal fungi benefit from organic matter decomposition primarily through increased nitrogen mobilization rather than through release of metabolic C and question the view that ectomycorrhizal fungi may act as facultative saprotrophs. Finally, we discuss how mycorrhizal decomposition may influence organic matter storage in soils and mediate responses of ecosystem C sequestration to environmental changes. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.


Marshall J.D.,University of Idaho | Marshall J.D.,Umea University | Linder S.,Swedish University of Agricultural Sciences
Tree Physiology | Year: 2013

The effects of the past century's increase in atmospheric CO2 concentration ([CO2]) have been recorded in the stable carbon isotope composition (13C) of the annual growth rings of trees. The isotope record frequently shows increases in photosynthetic CO2 uptake relative to stomatal conductance, which estimates the CO2 concentration gradient across the stomata (ca -ci). This variable, which is one control over the net photosynthetic rate, has been suggested as a homeostatic gas-exchange set point that is easy to estimate from 13C and [CO2]. However, in high-latitude conifer forests, the literature is mixed; some studies show increases in (ca -c i) and others show homeostasis. Here we present leaf and tree-ring 13C data from a controlled experiment that tested factorial combinations of elevated [CO2] (365 and 700 ∝mol mol -1) and fertilization on mature Norway spruce (Picea abies (L.) Karst.) trees in northern Sweden. We found first that the leaf carbon pool was contaminated by the current photosynthate in the older leaf cohorts. This is the reverse of the common observation that older photosynthate reserves can be used to produce new tissue; here the older tissue contains recent photosynthate. We found that the tree-ring data lack such contamination and in any case they better integrate over the canopy and the growing season than do leaves. In the second and third years of treatment, elevated [CO2] alone increased (ca -ci) by 38%; when combined with fertilization, it increased (ca -ci) by 60%. The results of this study support the idea that annual rings provide a clearer isotopic signal than do foliage age-classes. The tree-ring data show that inferred (ca -ci) depends not only on [CO2], but also on mineral-nutrient status. The differences in (ca -ci) are sufficiently large to account for the treatment-induced increase in wood-volume production in these stands. © 2013 The Author.


Brady M.,Swedish University of Agricultural Sciences | Sahrbacher C.,Leibniz Institute of Agricultural Development in Central and Eastern Europe | Kellermann K.,Leibniz Institute of Agricultural Development in Central and Eastern Europe | Happe K.,Leibniz Institute of Agricultural Development in Central and Eastern Europe
Landscape Ecology | Year: 2012

We present extensions to the agent-based agricultural policy simulator (AgriPoliS) model that make it possible to simulate the consequences of agricultural policy reform on farmers' land use decisions and concomitant impacts on landscape mosaic, biodiversity and ecosystem services in a real agricultural region. An observed population of farms is modelled as a multi-agent system where individual farm-agent behaviour and their interactions-principally competition for land-are defined through an optimization framework with land use and landscape impacts resulting as emergent properties of the system. The model is calibrated to real data on the farms and the landscape to be studied. We illustrate the utility of the model by evaluating the potential impacts of three alternative frameworks for the European Union Common Agricultural Policy (CAP) on landscape values in two marginal agricultural regions. Mosaic value was found to be sensitive to the choice of policy scheme in one of the landscapes, whereas significant trade-offs were shown to occur in terms of species richness by habitat and species composition at the landscape scale in both regions. The relationship between food production and other ecosystem services was found to be multifaceted. Thus illustrating the difficulty of achieving landscape goals in a particular region with simple or general land management rules (such as the current rules attached to CAPs direct payments). Given the scarcity of funding for conservation, the level and conditions for allocating direct payments are, potentially, of great importance for preserving landscape values in marginal agricultural regions (subject to levels of other support). © 2012 Springer Science+Business Media B.V.


Timonen J.,University of Jyvaskyla | Gustafsson L.,Swedish University of Agricultural Sciences | Kotiaho J.S.,University of Jyvaskyla | Monkkonen M.,University of Jyvaskyla
Biological Conservation | Year: 2011

The concept of Woodland Key Habitats (WKH, small-scaled presumed hotspots of biodiversity) has become an essential component of biodiversity conservation in Fennoscandian and Baltic forests. There have been debates over the importance of WKHs in relation to the conservation of biodiversity in production forests. We applied a systematic review protocol and meta-analysis to summarize knowledge on comparisons of biodiversity qualities, such as dead wood and species richness, between WKHs and production forests in relevant countries. We also summarized the knowledge on the impact of edge effects by comparing WKHs surrounded by production forests to WKHs surrounded by clear cuts. Studies had been conducted in Finland, Norway and Sweden. Based on our meta-analysis, WKHs seem to be relative hotspots for dead wood volume, diversity of dead wood, number of species and number of red-listed species. There were some differences also between countries in these biodiversity qualities. Only two studies compared WKHs surrounded by production forests and clear cuts, respectively. Hence, the capability of WKHs to maintain their original species composition and support species persistence over time remains to be addressed, as well as their role in relation to other conservation tools. © 2011 Elsevier Ltd.


Lindroos O.,Swedish University of Agricultural Sciences
Biomass and Bioenergy | Year: 2011

Firewood is society's oldest source of household energy and is still extensively used around the world. However, little is known about firewood usage in technologically advanced countries with high energy consumption. Some key issues include quantities of firewood currently used and future trends, as well as the influence of this usage on available biomass resources. This study addresses those issues through a postal questionnaire to 1500 of the firewood using households in a region in Northern Sweden. One-third of households produced 11-20 solid m3 of firewood per year. Three-fourths expected their production to be unchanged or increase during the coming five years. A large proportion of young producers indicated long-term continuation of firewood usage. Half (53%) of the firewood producing households owned forest and thereby had free access to wood. Produced firewood volume corresponded to 4-8% of the region's roundwood volume harvested for industrial purposes. The use of firewood is suggested to influence decisions of private forest owners about management and harvest of forest biomass, and, thus, affect supply for bioenergy and other uses. With further incorporation of firewood usage into forest biomass management regimes, larger biomass quantities are likely to be available for industrial uses. © 2010 Elsevier Ltd.


Ezebilo E.E.,Swedish University of Agricultural Sciences
Environmental Management | Year: 2012

The prior identification of local people's preferences for conservation-development projects will help gear nature-conservation strategies toward the needs of different groups of local people. This will help policy-makers in designing a more acceptable and effective conservation strategy. This article reports a study of local perceptions of a community forestry project that aims to help improve the design as well as local acceptance of the project. The data originated from personal interviews conducted in communities around Okwangwo Division of the Cross River National Park in southeast Nigeria and were analysed using ordered logit and binary logit models. The results showed that >50% of the respondents were satisfied with the community forestry project. The respondents' perceptions were mainly influenced by education, age, gender, and willingness to contribute money to tourism as well as the contributions of cocoa, banana, and afang (Gnetum africanum) to the respondents' income. The results from this study have important implications for nature conservation in Nigeria and potentially other conservation contexts across the developing world. © 2011 Springer Science+Business Media, LLC.


Filbakk T.,Norwegian University of Life Sciences | Jirjis R.,Swedish University of Agricultural Sciences | Nurmi J.,Finnish Forest Research Institute | Hoibo O.,Norwegian University of Life Sciences
Biomass and Bioenergy | Year: 2011

Increased use of pellets has resulted in a shortage of the traditional raw materials required for pellet making, including saw dust, shavings and cuttings from saw mills. Therefore, the pellets industry has started to look for alternative raw materials. Limited consumption of pulpwood from Scots pine (Pinus sylvestris L.) in Norway has made it a potential raw material for the pellets industry.A study on how bark content affects the quality of pellets is reported in this paper. Pellets from pinewood containing zero, five, 10, 30 and 100 percent bark were produced, and their quality parameters were evaluated. Combustion tests were also performed on the produced pellets.Pellets made from pure bark had the best mechanical properties compared with pellets made of wood containing various concentrations of bark. The differences were not substantial and the durability for all chosen assortments was in the same quality class in the CEN standard. A positive effect off the amount of steam added was found. The bulk densities of the blend pellets were higher than those of pure wood and bark. The ash content increased with the amount of bark in the pellets. There were no problems with sintering when the bark content was low (five and 10 percent). For pure bark pellets some sintering was registered. © 2010 Elsevier Ltd.


Junninen K.,University of Eastern Finland | Komonen A.,University of Eastern Finland | Komonen A.,Swedish University of Agricultural Sciences
Biological Conservation | Year: 2011

Here we quantitatively summarize the conservation ecology of one group of dead-wood-dependent organisms, the polyporous fungi, in boreal Europe. At the substrate scale, the decay stage is the strongest determinant of species richness, with large (>20cm diameter) downed logs hosting more species than other dead-wood types. At the stand scale, the amount of dead wood is the strongest determinant of polypore species richness; the minimum average amount of dead wood for the occurrence of rare polypores appears to be 20-40 m3/ha. Species-area analysis shows that in mature boreal forests species accumulation levels off at around 20-30ha. This leads us to suggest a heuristic 20/20/20 rule of thumb: a 20ha stand, with an average of 20 m3/ha of dead wood of which many are logs >20cm, is likely to be the minimum for the ecologically justified conservation of polypore diversity at the stand scale in boreal Europe. Equally crucial for polypore diversity, however, is the current and historic extent of suitable habitats at the landscape scale. The time lag between the isolation of a habitat patch and the new equilibrium in the number or occurrence of species seems to be around 100-150years, indicating that an extinction debt is likely to exist in recently isolated fragments. Only a few studies have addressed the ecological efficiency of the new, biodiversity-oriented forest management tools (retention trees, woodland key habitats). Despite this it seems that the traditional large conservation areas are the most effective means of polypore conservation. © 2010 Elsevier Ltd.


Gygax L.,ART Agroscope Reckenholz Tanikon | Reefmann N.,Swedish University of Agricultural Sciences | Wolf M.,University of Zurich | Langbein J.,Leibniz Institute for Farm Animal Biology
Behavioural Brain Research | Year: 2013

Recent concepts relating to animal welfare accept that animals experience affective states. These are notoriously difficult to measure in non-verbal species, but it is generally agreed that emotional reactions consist of well-coordinated reactions in behaviour, autonomic and brain activation. The aim of the study was to evaluate whether each or a combination of these aspects can differentiate between situations presumed to differ in emotional content. To this end, we repeatedly confronted dwarf goats at short intervals with a covered and an uncovered feed bowl (i.e. presumably frustrating and rewarding situations respectively) whilst simultaneously observing their behaviour, measuring heart-rate and heart-rate variability and haemodynamic changes in the prefrontal cortex using functional near-infrared spectroscopy. When faced with a covered feed bowl, goats occupied themselves at locations away from the bowl and showed increased locomotion, while there was a general increase in prefrontal cortical activity. There was little indication of autonomic changes. In contrast, when feed was accessible, the goats reduced locomotion, focused their behaviour on the feed bowl, showed signs of sympathetically mediated arousal reflecting anticipation and, if any cortical activity at all was present, it was concentrated to the left hemisphere. We thus observed patterns in behaviour, sympathetic reaction and brain activity that distinguished between a situation of frustration and one of reward in dwarf goats. These patterns consisted of a well-coordinated set of reactions appropriate in respect of the emotional content of the stimuli used. © 2012 Elsevier B.V..


Vanhanen L.P.,Lincoln University at Christchurch | Emmertz A.,Swedish University of Agricultural Sciences | Savage G.P.,Lincoln University at Christchurch
Food Chemistry | Year: 2011

The levels of 18 different minerals in ten locally produced mono-floral honeys (clover, honeydew, kmahi, mnuka, nodding thistle, rt, rewarewa, twari, thyme and viper's bugloss honey) were determined, as well as moisture content, pH, conductivity and colour. The most abundant minerals were potassium, phosphorus and calcium, ranging between 34.8-3640, 29.5-255 and 7.21-94.3 mg/kg, respectively. Potassium made up 73% of the total mineral content. There was a large range of mean total mineral contents, with honeydew honey having the highest level (4060 mg/kg) and viper's bugloss honey the lowest (126 mg/kg). Honeydew had more than twice the mean total mineral contents than kmahi, the next highest. The heavy metal contents (Cd, Pb and Zn) of the mono-floral honey types investigated were very low. A strong positive relationship between mean conductivity and total mineral content (r2 = 0.973), and pH and total mineral content (r2 = 0.776) was observed in this study. © 2011 Elsevier Ltd. All rights reserved.


Huuskonen A.,Mtt Agrifood Research Finland | Huhtanen P.,Swedish University of Agricultural Sciences | Joki-Tokola E.,Mtt Agrifood Research Finland
Animal | Year: 2014

The objective of this meta-analysis was to develop empirical equations predicting growth responses of growing cattle to protein intake. Overall, the data set comprised 199 diets in 80 studies. The diets were mainly based on grass silage or grass silage partly or completely replaced by whole-crop silages or straw. The concentrate feeds consisted of cereal grains, fibrous by-products and protein supplements. The analyses were conducted both comprehensively for all studies and also separately for studies in which soybean meal (SBM; n=71 diets/28 studies), fish meal (FM; 27/12) and rapeseed meal (RSM; 74/35) were used as a protein supplement. Increasing dietary CP concentration increased (P<0.01) BW gain (BWG), but the responses were quantitatively small (1.4 g per 1 g/kg dry matter (DM) increase in dietary CP concentration). The BWG responses were not different for bulls v. steers and heifers (1.4 v. 1.3 g per 1 g/kg DM increase in dietary CP concentration) and for dairy v. beef breeds (1.2 v. 1.7 g per 1 g/kg, respectively). The effect of increased CP concentration declined (P<0.01) with increasing mean BW of the animals and with improved BWG of the control animals (the lowest CP diet in each study). The BWG responses to protein supplementation were not related to the CP concentration in the control diet. The BWG responses increased (P<0.05) with increased ammonia N concentration in silage N and declined marginally (P>0.10) with increasing proportion of concentrate in the diet. All protein supplements had a significant effect on BWG, but the effects were greater for RSM (P<0.01) and FM (P<0.05) than for SBM. Increasing dietary CP concentration improved (P<0.01) feed efficiency when expressed as BWG/kg DM intake, but decreased markedly when expressed as BWG/kg CP intake. Assuming CP concentration of 170 g/kg BW marginal efficiency of the utilisation of incremental CP intake was only 0.05. Increasing dietary CP concentration had no effects on carcass weight, dressing proportion or conformation score, but it increased (P<0.01) fat score. Owing to limited production responses, higher prices of protein supplements compared with cereal grains and possible increases the N and P emissions, there is generally no benefit from using protein supplementation for growing cattle fed grass silage-based diets, provided that the supply of rumen-degradable protein is not limiting digestion in the rumen. © The Animal Consortium 2014.


Kreyling J.,University of Bayreuth | Haei M.,Umea University | Laudon H.,Swedish University of Agricultural Sciences
Oecologia | Year: 2012

Snow regimes affect biogeochemistry of boreal ecosystems and are altered by climate change. The effects on plant communities, however, are largely unexplored despite their influence on relevant processes. Here, the impact of snow cover on understory community composition and below-ground production in a boreal Picea abies forest was investigated using a long-term (8-year) snow cover manipulation experiment consisting of the treatments: snow removal, increased insulation (styrofoam pellets), and control. The snow removal treatment caused longer (118 vs. 57 days) and deeper soil frost (mean minimum temperature -5. 5 vs. -2. 2°C) at 10 cm soil depth in comparison to control. Understory species composition was strongly altered by the snow cover manipulations; vegetation cover declined by more than 50% in the snow removal treatment. In particular, the dominant dwarf shrub Vaccinium myrtillus (-82%) and the most abundant mosses Pleurozium schreberi (-74%) and Dicranum scoparium (-60%) declined strongly. The C:N ratio in V. myrtillus leaves and plant available N in the soil indicated no altered nitrogen nutrition. Fine-root biomass in summer, however, was negatively affected by the reduced snow cover (-50%). Observed effects are attributed to direct frost damage of roots and/ or shoots. Besides the obvious relevance of winter processes on plant ecology and distribution, we propose that shifts in the vegetation caused by frost damage may be an important driver of the reported alterations in biogeochemistry in response to altered snow cover. Understory plant performance clearly needs to be considered in the biogeochemistry of boreal systems in the face of climate change. © 2011 Springer-Verlag.


Katul G.G.,Duke University | Katul G.G.,Polytechnic University of Turin | Oren R.,Duke University | Oren R.,Swedish University of Agricultural Sciences | And 3 more authors.
Reviews of Geophysics | Year: 2012

The role of evapotranspiration (ET) in the global, continental, regional, and local water cycles is reviewed. Elevated atmospheric CO 2 , air temperature, vapor pressure deficit (D), turbulent transport, radiative transfer, and reduced soil moisture all impact biotic and abiotic processes controlling ET that must be extrapolated to large scales. Suggesting a blueprint to achieve this link is the main compass of this review. Leaf-scale transpiration ( f e) as governed by the plant biochemical demand for CO 2 is first considered. When this biochemical demand is combined with mass transfer formulations, the problem remains mathematically intractable, requiring additional assumptions. A mathematical "closure" that assumes stomatal aperture is autonomously regulated so as to maximize the leaf carbon gain while minimizing water loss is proposed, which leads to analytical expressions for leaf-scale transpiration. This formulation predicts well the effects of elevated atmospheric CO 2 and increases in D on f e. The case of soil moisture stress is then considered using extensive gas exchange measurements collected in drought studies. Upscaling the f e to the canopy is then discussed at multiple time scales. The impact of limited soil water availability within the rooting zone on the upscaled ET as well as some plant strategies to cope with prolonged soil moisture stress are briefly presented. Moving further up in direction and scale, the soil-plant system is then embedded within the atmospheric boundary layer, where the influence of soil moisture on rainfall is outlined. The review concludes by discussing outstanding challenges and how to tackle them by means of novel theoretical, numerical, and experimental approaches. © 2012. American Geophysical Union.


Butler A.,Swedish University of Agricultural Sciences
Landscape Research | Year: 2016

While there has been extensive research undertaken on the values which insiders attribute to landscape there is a lack of literature which looks at how planning professionals handle landscape values. In this article, I develop a framework for questioning how landscape values are taken up in landscape planning, with the aim of conceptualising what landscape values mean in practice. This is undertaken through addressing landscape assessment, more specifically analysing how landscape character assessment (LCA) represents a critical point in the framing of landscape values. Through a synthesis of research on landscape values I examine the underlying logic of the LCA documents. I conclude that the values communicated in these assessments tend to be those of ‘objective’ outside experts, predominantly based on aesthetics and focusing on the physicality of landscape. This I argue leads to a questioning the legitimacy of the LCA approach. © 2016 Landscape Research Group Ltd


Aim: Assessing long-term (1992-2009) trends of littoral invertebrate and phytoplankton metacommunities in boreal lakes with emphasis on separating the nestedness and turnover components of beta diversity. Deriving implications for regional biodiversity conservation and management, based on a data-intensive approach with high ecological realism. Location: Sweden (Northern Europe). Methods: A recently published method was used to partition beta diversity into species turnover and nestedness components. Regression analyses were used to test for monotonic temporal change of these diversity fractions through time. Associations between the temporal diversity patterns of taxonomic groups and environmental variables were studied using correlation analyses. Results: Turnover of both metacommunities increased monotonically over the study period, while nestedness decreased. In invertebrates, these changes correlated mainly with regional changes in acidity, while phytoplankton responded more to changing water clarity. Nestedness and turnover patterns were inversely correlated in both groups, but neither turnover nor nestedness was correlated between invertebrates and phytoplankton. Nestedness of both groups explained a lower percentage of the partitioned variance compared with turnover. Main conclusion: Results suggest that all lakes contribute more equally to regional diversity over time and are, as a result, all potential targets of management actions. Not only is a regional conservation strategy logistically difficult, it is also a financially expensive expectation. © 2013 John Wiley & Sons Ltd.


Berggren A.,Swedish University of Agricultural Sciences
Insect Science | Year: 2010

Despite the growing interest in how an individual's immune response is correlated to morphological and ecological factors, little empirical data has been available from wild insect populations. Many insects have different color morphs and exhibit differences in immune responses. Links are expected to exist between body colors and immune function in insects, because the same biochemical precursors involved in the immune response are responsible for melanin-based color markings. In this study, I assay the immune response of two different color morphs of 377 wild-caught bush-crickets, Metrioptera roeseli, from 20 populations by measuring individual encapsulation responses to a surgically implanted nylon monofilament. There was no difference between green and brown bush-cricket morphs (low melanin vs high melanin investment in cuticula color respectively) and their ability to mount an immune response to the implant. Further study is needed on the relationship between color morphology and immune response in wild insects, and whether trade-offs occur between factors during an insect's development phase and long-term health. © 2010 The Author Journal compilation © Institute of Zoology, Chinese Academy of Sciences.


Arthurson V.,Swedish University of Agricultural Sciences
World Journal of Microbiology and Biotechnology | Year: 2011

The aim of this study was to determine the impact of storage, animal diet, and animal source on the bacterial community composition of manure. The differences among bacterial community structures in fresh manure from cows on two different diets, cow manure stored in a deep pit for about one month, and fresh pig manure were compared. A molecular approach consisting of terminal restriction fragment length polymorphism (T-RFLP), in combination with sequence information from clone libraries, facilitated the identification of specific dominant bacterial populations that varied significantly among manures from different sources and treatments. One such population, represented by TRF 157, the most dominant peak of the bacterial community from stored manure, was identified as a Spirochaeta sp. Interestingly, this peak was absent in the fresh manure communities. The prevailing species in the fresh manure bacterial communities were distinct from those in manure from the storage pit, indicating a major shift in bacterial community composition induced by storage conditions. Moreover, distinct differences in bacterial communities were observed among animal source, but not animal feed. Manure storage is consequently an important parameter to consider when handling fertilizers, in order to obtain an optimal soil microbial ecosystem functioning. © 2011 Springer Science+Business Media B.V.


Rosenqvist H.,Swedish University of Agricultural Sciences | Berndes G.,Chalmers University of Technology | Borjesson P.,Lund University
Biomass and Bioenergy | Year: 2013

The current and future costs of willow short rotation coppice production in Sweden are analysed, considering all relevant cost factors explicitly. The future production costs are estimated considering effects of coppice area expansion and learning. The current and future costs of land and of risk premiums are subsequently estimated. Subsidies for farmers are not considered. If the area of willow cultivation were to expand enough to generate economies of scale, the production cost could be cut by about 10% compared to the current level. When learning effects are also considered, the total cost reduction potential is about 35%. Two major cost components (fertilization and road transport) are roughly stable while two other major cost components (establishment and harvest) have larger prospects for cost reduction, primarily due to potential for learning. Land costs and risk premiums vary and are uncertain, but both are estimated to be potentially significant compared to other cost components. Requirements of risk premiums may become lower as a consequence of area expansion and learning. Land costs are subject to many factors that are inherently uncertain, not the least future food prices. Efficient policies promoting an expansion of willow cultivation are discussed. © 2012 Elsevier Ltd.


Sarlov Herlin I.,Swedish University of Agricultural Sciences
Landscape Research | Year: 2016

Countries ratifying the European Landscape Convention (ELC) agree to identify their landscapes, analyse their characteristics and assess the landscapes taking into account the values afforded them by the population. Some UK countries, such as England, are regarded as pioneers of these ideas and implementation of ELC principles even before it was drafted. Since the early 1990s, England (and Scotland) has been ahead of many countries in the development of methods for characterisation and identification of landscapes. However, such landscape assessment methods have been developed within a specific and distinctive historical context. This paper attempts to define the subtext of English landscape identity that may be ‘lost in translation’ or ignored when these methods are exported to other countries. The paper first outlines three major, interlinked aspects of ideas and societal development that have specifically affected development of landscape conservation and planning and landscape assessment methods in England, namely: (i) ideas from landscape conservation; (ii) countryside protection and planning in the early twentieth century; and (iii) institutionalisation and development of post-war planning and conservation practices. The paper also examines Landscape Character Assessment and discusses ways in which the national context may need to be considered when using this method. © 2016 Landscape Research Group Ltd


Vogel N.,Swedish University of Agricultural Sciences
Journal of Environmental Policy and Planning | Year: 2015

In contemporary planning discourse and practice, different planning ideas co-exists. How this affects the transition towards a sustainable development is an important question for both research and practice. The aim of this study is to explore potential conflicts between planning goals caught between growth-led planning and sustainability commitments in a case study of Fredericia, Denmark. The paper discusses the underlying, framing and controlling conditions for transition dynamics. The analysis builds largely on the formulated policies, strategies or national goal achievements towards sustainable futures. These are put in the context of planning and political practices, which are interpreted from a sustainability rationale. Here this study introduces hypocrisy as a theoretical-analytical perspective to dispute actual sustainability practices to respond to continuous ambivalent planning measures. The author concludes that disregarding the inherently different internal logics of growths and sustainability leads to planning paradoxes and impedes sustainable transitions pursued. © 2015 Taylor & Francis


Gustafsson L.,Swedish University of Agricultural Sciences | Perhans K.,University of Queensland
Ambio | Year: 2010

A multi-scaled model for biodiversity conservation in forests was introduced in Sweden 30 years ago, which makes it a pioneer example of an integrated ecosystem approach. Trees are set aside for biodiversity purposes at multiple scale levels varying from individual trees to areas of thousands of hectares, with landowner responsibility at the lowest level and with increasing state involvement at higher levels. Ecological theory supports the multi-scaled approach, and retention efforts at every harvest occasion stimulate landowners' interest in conservation. We argue that the model has large advantages but that in a future with intensified forestry and global warming, development based on more progressive thinking is necessary to maintain and increase biodiversity. Suggestions for the future include joint planning for several forest owners, consideration of cost-effectiveness, accepting opportunistic work models, adjusting retention levels to stand and landscape composition, introduction of temporary reserves, creation of "receiver habitats" for species escaping climate change, and protection of young forests. © 2010 Royal Swedish Academy of Sciences.


Kardol P.,Swedish University of Agricultural Sciences | De Deyn G.B.,Wageningen University | Laliberte E.,University of Western Australia | Mariotte P.,Swiss Federal Institute of forest | Hawkes C.V.,University of Texas at Austin
Journal of Ecology | Year: 2013

Plant effects on soil biota can result in feedbacks affecting plant performance, with consequences for plant community and ecosystem dynamics on short and long time-scales. In addition, the strength and direction of plant-soil feedbacks depend on temporal shifts in abiotic environmental conditions. We synthesize current knowledge on temporal aspects of plant-soil feedbacks and present new ideas to better understand and predict the effects of plant-soil feedbacks on community and ecosystem properties across temporal scales. Explaining short-term temporal feedback dynamics requires us to better understand mechanistic linkages between plants, soil organisms and locally available resources. On the other hand, we need to refine our understanding of the context-dependency of plant-soil feedbacks, as the strength and direction of feedback interactions are influenced by 'external' temporal ecosystem dynamics, such as variation in soil resource availability after disturbance or during succession. Synthesis. Based on our synthesis of temporal aspects of plant-soil feedbacks, we suggest three main avenues for future research: (i) how plant-soil feedbacks changes with ontogeny, (ii) how plant and soil organism traits drive temporal variation in plant-soil feedbacks and (iii) how environmental changes across temporal scales alter the strength and direction of plant-soil feedbacks. © 2013 The Authors. Journal of Ecology © 2013 British Ecological Society.


Magnhagen C.,Swedish University of Agricultural Sciences
Current Zoology | Year: 2012

Lately, there has been an increasing interest in intraspecific variation in behaviour, and numerous studies on personality have been performed in a variety of animals, including several fish species. Individuals have been divided into coping style categories or arranged along a behaviour gradient, such as the bold/shy continuum. However, many fish species live in groups, and the social environment can influence the behaviour of an animal in different ways. There may be conflicts within groups due to competition for resources, and dominance hierarchies are commonly found. On the other hand, there are many benefits of consensus decision-making within the group. Conformity of behaviour is probably adaptive, due to the benefit of public information on, for example, food resources and predation risk. Accordingly, studies of fish shoals have found evidence of consensus decision- making. Furthermore, factors in the environment, such as predation risk would also influence the behaviour expressed. To be able to understand behaviour patterns in a group of fish, it is necessary to consider the variation of individual characteristics, and how the group, as well as other environmental factors, affects the behaviour of individuals. Here, I will review studies on different aspects of personality within a social context in fish, with a special emphasis on the Eurasian perch Perca fluviatilis. © 2012 Current Zoology.


Ciannelli L.,Oregon State University | Bartolino V.,Swedish University of Agricultural Sciences | Bartolino V.,Gothenburg University | Chan K.-S.,University of Iowa
Proceedings of the Royal Society B: Biological Sciences | Year: 2012

Density-independent and density-dependent variables both affect the spatial distributions of species. However, their effects are often separately addressed using different analytical techniques. We apply a spatially explicit regression framework that incorporates localized, interactive and threshold effects of both density-independent (water temperature) and density-dependent (population abundance) variables, to study the spatial distribution of a well-monitored flatfish population in the eastern Bering Sea. Results indicate that when population biomass was beyond a threshold a further increase in biomass-promoted habitat expansion in a non-additive fashion with water temperature. In contrast, during years of low population size, habitat occupancy was affected positively only by water temperature. These results reveal the spatial signature of intraspecific abundance distribution relationships as well as the non-additive and non-stationary responses of species spatial dynamics. Furthermore, these results underscore the importance of implementing analytical techniques that can simultaneously account for density-dependent and density-independent sources of variability when studying geographical distribution patterns. © 2012 The Royal Society.


Blennow K.,Swedish University of Agricultural Sciences
Forest Policy and Economics | Year: 2012

Available climate change scenarios indicate that climate change will affect elements of the Swedish climate, and that the exposure and sensitivity of the forest to climate change will differ between regions. Adaptation to climate change is conceptually closely linked to the reduction of the risk of disasters. Based on contemporary theory in behavioural risk research, the aim was to improve the knowledge on the process of adaptation of forest management to climate change among Swedish private individual forest owners. The responses from two questionnaires from 1999 to 2004, respectively, were analysed. Adaptation of forest management to climate change by private individual forest owners in what is currently the hemiboreal bio-climatic zone of Sweden was quantified and shown to increase over the five year period. In 2004 adaptive measures had been taken on a limited fraction of the forest land owned by private individuals in three study areas located along a latitudinal gradient ranging from the nemoral to the boreal bio-climatic zones in Sweden. Adaptive measures were more frequent in two southern study areas than in a northern study area. Measures taken to adapt were similar in all three study areas, except for those strongly conditioned by the current local climate. Among forest owners who had taken measure to adapt, perceptions of much higher risk due to climate change was more frequent for the risk of damage by wind, drought, fungi, and insects than for other risk factors. Further improvement of the knowledge on how the individual forest owners' learn and perceive of climate change, its impacts on risks and options for adaptation is required to develop and successfully implement adaptive climate change policies. © 2011 Elsevier B.V.


Cardinale M.,Swedish University of Agricultural Sciences | Hjelm J.,Havs och vattenmyndigheten
Marine Policy | Year: 2012

The maximum sustainable yield concept (MSY) and the ecosystem approach to fisheries management (EAFM) have been recently adopted by the European Commission with the objective to achieve, over the long term, the highest possible sustainable yield from a given exploited stock. In this context, a fishing mortality MSY reference level (i.e., FMSY) should be defined, taking into account recruitment, growth and natural mortality under current or recent ecosystem conditions. Thus, FMSY is used as a generic term for a robust estimate of a fishing mortality level that is associated with high sustainable yield in the long term, assuming the current harvesting regime in terms of size selectivity. In this study, using the Eastern Baltic cod as an example, we challenge this rather simplified view showing that by using a different harvest selectivity and thus changing the size range of harvested cod, it is possible to largely increase the yield and revenue from the fishery compared to the fishing mortality stipulated in the management plan (i.e., FMSY), while assuring sustainable high yield in the long term. Thus, implementing the MSY concept in terms of fishing mortality but neglecting selective harvesting effects will not achieve high long term sustainable yield for Eastern Baltic cod. The combination of size selective harvesting and economic reasoning may offer an important tool for the management of marine resources by potentially providing a common currency for the different stakeholders and offer guidance to achieve long term sustainability and human well-being. This would represent the natural step forward in the implementation of EAFM and MSY concepts. © 2012 Elsevier Ltd.


Zhang J.,University of Helsinki | Elo A.,University of Helsinki | Helariutta Y.,University of Helsinki | Helariutta Y.,Swedish University of Agricultural Sciences
Current Opinion in Biotechnology | Year: 2011

Wood (secondary xylem) is one of the most important sustainable energy sources for humans. Arabidopsis, despite its herbaceous nature, has become an excellent model to study wood formation. Recent progress has shown that conserved molecular mechanisms may exist in herbaceous plants and trees during vascular development and wood formation. Several transcription factor families and plant hormone species as well as other factors contribute to the regulation of xylem development in both Arabidopsis and woody plants. In this review, we highlight how information gained from the analysis of vascular development in Arabidopsis has improved our understanding of wood formation in trees. © 2010 Elsevier Ltd.


Rising A.,Swedish University of Agricultural Sciences | Johansson J.,Center for Alzheimer Research
Nature Chemical Biology | Year: 2015

Spider silk is strong and extensible but still biodegradable and well tolerated when implanted, making it the ultimate biomaterial. Shortcomings that arise in replicating spider silk are due to the use of recombinant spider silk proteins (spidroins) that lack native domains, the use of denaturing conditions under purification and spinning and the fact that the understanding of how spiders control silk formation is incomplete. Recent progress has unraveled the molecular mechanisms of the spidroin N- and C-terminal nonrepetitive domains (NTs and CTs) and revealed the pH and ion gradients in spiders' silk glands, clarifying how spidroin solubility is maintained and how silk is formed in a fraction of a second. Protons and CO2, generated by carbonic anhydrase, affect the stability and structures of the NT and CT in different ways. These insights should allow the design of conditions and devices for the spinning of recombinant spidroins into native-like silk. © 2015 Nature America, Inc. All rights reserved.


Andersson M.,Swedish University of Agricultural Sciences
Journal of Forest Economics | Year: 2012

This study relates owner and property characteristics to non-industrial private forest (NIPF) owners' attitudes to financial risk-taking in forestry decisions. Using a two-period mean-variance setting, the harvesting decisions of NIPF owners are examined with the aim of measuring their willingness to take risks. Since willingness to pay for reduction of risk is empirically unobservable, I rely on an index of NIPF owners' attitudes to risk from a hypothetical survey question involving financial risk. According to the index, respondents (owners) are categorized as risk-averse, risk-neutral or risk-seeking. I apply a probit analysis to test how owner and property characteristics influence the NIPF owners' attitudes to risk. The results show that characteristics influence the formation of risk attitudes. More explicitly, a longer period of ownership increases the probability that the owner is risk-averse, while increased time in the forest conducting silvicultural work increases the likelihood that an owner is risk-seeking. The results also show that female NIPF owners are more risk-seeking than male owners. The study fills a knowledge gap in the literature, relating owner and property characteristics to management decisions. Inclusion of risk attitudes and the judgement of risks into studies of NIPF owners' management can help to understand why NIPF owners' harvesting may deviate from net present value maximisation. © 2011 Department of Forest Economics, SLU Umeå, Sweden.


Wibe S.,Swedish University of Agricultural Sciences
Journal of Forest Economics | Year: 2012

It is often assumed that wood fuels are carbon neutral. This is approximately true in the very long run since the emissions from burning wood fuels are compensated by the uptake from new trees. But it is not true in the short- and the medium term due to a number of factors. This problem is analyzed in detail in this paper, where the net carbon (dioxide) effect of using wood residues in Sweden 1980-2100 is calculated. Two important implications of the program for using wood fuels are considered: (i) the decrease of carbon stored in logging residues due to a faster transformation to carbon dioxide and (ii) delayed growth of new forest generations when logging residues are removed from the forest and used as fuel. The effects of both these factors are calculated (and projected) for the period 1980-2100. The main result is that wood fuels (in the form of wood residues) emits about 60% of the carbon dioxide that would have been emitted if the corresponding amount of energy would, have been produced by oil. One policy implication of this is that emissions from wood fuels should not, as is now the practice, be ignored and by definition equaled to zero, in national and international statistics of green house gas emissions. © 2011 Department of Forest Economics, Swedish University of Agricultural Sciences, Umeå.


Raitio K.,University of Eastern Finland | Raitio K.,Swedish University of Agricultural Sciences
Land Use Policy | Year: 2012

Collaborative planning has become an increasingly popular approach in environmental decision-making, particularly in situations where there are multiple actors with conflicting interests. In this paper, collaborative environmental planning is perceived as being embedded in an institutional environment that has an impact on the processes and outcomes of planning. Building on the theory of new institutionalism, the paper combines legal analysis of forest regulation with interviews and policy document data from two case studies on collaborative Natural Resource Planning in state-owned forests in Finland. These approaches will be used to analyse how formal regulations and informal norms are interpreted and implemented in the planning processes. The paper highlights the important role institutions can play in promoting or hindering successful collaborative planning, and makes recommendations for developing a forest governance system that is equipped to deal with the identified challenges. © 2011 Elsevier Ltd.


Brannas E.,Swedish University of Agricultural Sciences
Journal of Fish Biology | Year: 2014

Feeding activity from a larger refuge site into two visually separated feeding sites with temporally restricted food availability, one in the morning and one in the evening was studied in duplicate groups of Arctic charr Salvelinus alpinus. A passive integrated transponder (PIT) system enabled continuous monitoring of individual movements between the sites. Both groups synchronized their diel pattern of visit activity to the two feeding sites when food was available. One group showed significant anticipatory visit activity into both feeding sites during the hours before the feed was available, suggesting a time and place learning of resource availability. The anticipatory activity of the other group was, however, less pronounced and only occurred into one of the feeding sites. Individual S. alpinus entered the feeding sites independently and no obvious patterns of leaders and followers were identified. All S. alpinus gained mass and moved between a refuge and the feeding sites. Different strategies of how individual S. alpinus utilized the feeding sites were not correlated with growth. © 2013 The Fisheries Society of the British Isles.


Webster B.,Swedish University of Agricultural Sciences
Physiological Entomology | Year: 2012

Aphids are major economic pests of many of the worlds' crops, causing damage directly by feeding and by acting as vectors for plant viruses. By understanding how aphids locate their host plants, it may become possible to develop new means of controlling populations by taking advantage of these natural host location/nonhost avoidance behaviours. Aphids have also become important model organisms in the study of insect-plant interactions and an improved understanding of host location in aphids could yield insights into the behaviour and ecology of other insect orders. The use of olfaction by host-seeking aphids is well documented and, in recent years, considerable information has been gained on how volatiles can encode host identity and suitability, as well as the specific behaviours they elicit from aphids. The purpose of this review is to highlight the major findings on how aphids respond behaviourally to volatile compounds and how they can use them to locate their host plants and avoid unsuitable hosts. © 2012 The Author. Physiological Entomology © 2012 The Royal Entomological Society.


Di Corato L.,Swedish University of Agricultural Sciences | Moretto M.,Fondazione Eni Enrico Mattei
Energy Economics | Year: 2011

In a stochastic dynamic frame, we study the technology choice problem of a continuous co-digestion biogas plant where input factors are substitutes but need to be mixed together to provide output. Given any initial rule for the composition of the feedstock, we consider the possibility of revising it if economic circumstances make it profitable. Flexibility in the mix is an advantage under randomly fluctuating input costs and comes at a higher investment cost. We show that the degree of flexibility in the productive technology installed depends on the value of the option to profitably re-arrange the input mix. Such option adds value to the project in that it provides a device for hedging against fluctuations in the input relative convenience. Accounting for such value we discuss the trade-off between investment timing and profit smoothing flexibility. © 2011 Elsevier B.V.


Hedhammar A.A.,Swedish University of Agricultural Sciences | Indrebo A.,Norwegian Kennel Club
Veterinary Journal | Year: 2011

The structure and aims of the Fédération Cynologique Internationale (FCI) are outlined, with a focus on the rules and regulations that are relevant to breeding and genetic health of dogs. Recently adopted strategies to enhance canine genetic health and activities to counteract exaggerated anatomical features are highlighted. Actions by the FCI regarding recognition of breeds and doping rules, under direct control by cynological organisations, are included, based on their relevance to canine health. © 2011 Elsevier Ltd.


Solovyev A.G.,Moscow State University | Savenkov E.I.,Swedish University of Agricultural Sciences
Journal of Experimental Botany | Year: 2014

Compatible virus-host interactions depend on a suitable milieu in the host cells permitting viral gene expression, replication, and spread. During pathogenesis, viruses hijack the plant cellular machinery to access molecules, subcellular structures, and host transport pathways needed for infection. Vascular trafficking of virus transport forms (VTF) within the phloem is a crucial step in setting-up virus infection within the entire plant. Moreover, vascular trafficking is an essential step for the further transmission of the viruses by their natural vectors as movement of the viruses to the distant parts of the plant from the initial site of infection guarantees accessibility of the virus particle for vector transmission. With the recent advances in the field of plant virology several emerging themes of viral systemic movement occur linking the role of virus-mediated transcriptional reprogramming and nuclear factors in vascular trafficking. Recent studies have uncovered host factors involved in virus vascular trafficking. Surprisingly, it appears that the role of the nucleus and nuclear factors in virus movement is still under-appreciated. This review describes how these new themes started to emerge by using two contrasting modes of virus vascular trafficking. It is argued that the translocation of viral movement proteins into the nuclei is, in many cases, an essential step in promoting virus systemic infection. © 2013 The Author.


Oosten J.E.,University of Groningen | Magnhagen C.,Swedish University of Agricultural Sciences | Hemelrijk C.K.,University of Groningen
Behavioral Ecology and Sociobiology | Year: 2010

Most studies of animal personality attribute personality to genetic traits. But a recent study by Magnhagen and Staffan (Behav Ecol Sociobiol 57:295-303, 2005) on young perch in small groups showed that boldness, a central personality trait, is also shaped by social interactions and by previous experience. The authors measured boldness by recording the duration that an individual spent near a predator and the speed with which it fed there. They found that duration near the predator increased over time and was higher the higher the average boldness of other group members. In addition, the feeding rate of shy individuals was reduced if other members of the same group were bold. The authors supposed that these behavioral dynamics were caused by genetic differences, social interactions, and habituation to the predator. However, they did not quantify exactly how this could happen. In the present study, we therefore use an agent-based model to investigate whether these three factors may explain the empirical findings. We choose an agent-based model because this type of model is especially suited to study the relation between behavior at an individual level and behavioral dynamics at a group level. In our model, individuals were either hiding in vegetation or feeding near a predator, whereby their behavior was affected by habituation and by two social mechanisms: social facilitation to approach the predator and competition over food. We show that even if we start the model with identical individuals, these three mechanisms were sufficient to reproduce the behavioral dynamics of the empirical study, including the consistent differences among individuals. Moreover, if we start the model with individuals that already differ in boldness, the behavioral dynamics produced remained the same. Our results indicate the importance of previous experience and social interactions when studying animal personality empirically. © The Author(s) 2010.


Englund G.,Umea University | Eriksson H.,Umea University | Nilsson M.B.,Swedish University of Agricultural Sciences
Geophysical Research Letters | Year: 2013

Ongoing land uplift caused by postglacial isostatic rebound creates strong landscape-age gradients alongside the Gulf of Bothnia, northern Scandinavia. Lakes are continuously generated on this dynamic landscape as the uplift isolates bays from sea inundation. However, concomitant with this process older lakes are lost as the basins are filled with sediments, creating a continuum of lake ages on the landscape. We studied the lake size and depth distributions and lake densities, along an age gradient covering 0-4500 years. Map data on the density, area, and elevation of lakes were combined with field-based measurements of maximum basin depth. We find that young lake populations are densely distributed and dominated by small and shallow lakes. Over time, small and shallow lakes are lost by complete sediment filling, resulting in lower lake density and a shift in size and depth distributions towards larger, deeper lakes. Since lake filling is a universal process, we propose that these findings can be generalized to other gradients in landscape age. Key Points Lake density decreases with increasing landscape age The proportion of small lakes decreases with increasing landscape age The proportion of shallow lakes decreases with increasing landscape age ©2013. American Geophysical Union. All Rights Reserved.


Seitz F.,University of Koblenz-Landau | Bundschuh M.,University of Koblenz-Landau | Bundschuh M.,Swedish University of Agricultural Sciences | Rosenfeldt R.R.,University of Koblenz-Landau | Schulz R.,University of Koblenz-Landau
Aquatic Toxicology | Year: 2013

The increasing use of titanium dioxide nanoparticles (nTiO2) inevitably results in their release into the environment, raising concerns about potential adverse effects in wildlife. By following standard test protocols, several studies investigated the ecotoxicity of nTiO2 among others to Daphnia magna. These studies indicated a large variability - several orders of magnitude - in the response variables. However, other factors, like nanoparticle characteristics and test design, potentially triggering these differences, were largely ignored. Therefore, the present study assessed the chronic ecotoxicity of two nTiO2 products with varying crystalline structure (A-100; P25) to D. magna. A semi-static and a flow-through exposure scenario were compared, ensuring that both contained environmentally relevant concentrations of dissolved organic carbon. Utilizing the semi-static test design, a concentration as low as 0.06mg/L A-100 (∼330nm) significantly reduced the reproduction of daphnia indicating environmental risk. In contrast, no implication in the number of released offspring was observed during the flow-through experiment with A-100 (∼140nm). Likewise, P25 (∼130nm) did not adversely affect reproduction irrespective of the test design utilized. Given the present study's results, the particle size, the product composition, i.e. the crystalline structure, and the accumulation of nTiO2 at the bottom of the test vessel - the latter is relevant for a semi-static test design - may be suggested as factors potentially triggering differences in nTiO2 toxicity to D. magna. Hence, these factors should be considered to improve environmental risk assessment of nanoparticles. © 2012 Elsevier B.V.


Aichinger E.,ETH Zurich | Aichinger E.,Albert Ludwigs University of Freiburg | Villar C.B.R.,ETH Zurich | di Mambro R.,University of Rome La Sapienza | And 3 more authors.
Plant Cell | Year: 2011

The chromatin modifying Polycomb group (PcG) and trithorax group (trxG) proteins are central regulators of cell identity that maintain a tightly controlled balance between cell proliferation and cell differentiation. The opposing activities of PcG and trxG proteins ensure the correct expression of specific transcriptional programs at defined developmental stages. Here, we report that the chromatin remodeling factor PICKLE (PKL) and the PcG protein CURLY LEAF (CLF) antagonistically determine root meristem activity. Whereas loss of PKL function caused a decrease in meristematic activity, loss of CLF function increased meristematic activity. Alterations of meristematic activity in pkl and clf mutants were not connected with changes in auxin concentration but correlated with decreased or increased expression of root stem cell and meristem marker genes, respectively. Root stem cell and meristem marker genes are modified by the PcG-mediated trimethylation of histone H3 on lysine 27 (H3K27me3). Decreased expression levels of root stem cell and meristem marker genes in pkl correlated with increased levels of H3K27me3, indicating that root meristem activity is largely controlled by the antagonistic activity of PcG proteins and PKL. © 2011 American Society of Plant Biologists.


Dovlen S.,Swedish University of Agricultural Sciences
Landscape Research | Year: 2016

The European Landscape Convention (ELC) aims to promote landscape protection, management and planning and to organise European cooperation on landscape issues. The introduction of the ELC in 2000 created a need for further theoretical work within the field of landscape research, which has historically provided a weak theoretical basis for policy implementation. In this study, a relational approach was used to investigate the ongoing ELC implementation process in Sweden, illustrating government dynamics and highlighting efforts to transform discourses and practices. The conceptual framework used comprised three analytical components (policy community, policy meaning and strategy-making practice) and the relational approach was applied at national, regional and local policy levels. The results revealed both progress and obstacles to ELC implementation in Sweden and confirmed the usefulness of the relational approach. © 2016 Landscape Research Group Ltd


Blomfeldt T.O.J.,KTH Royal Institute of Technology | Kuktaite R.,KTH Royal Institute of Technology | Johansson E.,Swedish University of Agricultural Sciences | Hedenqvist M.S.,KTH Royal Institute of Technology
Biomacromolecules | Year: 2011

This Article reports the influence of the protein network structure on the mechanical properties of foams produced from commercial wheat gluten using freeze-drying. Foams were produced from alkaline aqueous solutions at various gluten concentrations with or without glycerol, modified with bacterial cellulose nanosized fibers, or both. The results showed that 20 wt % glycerol was sufficient for plasticization, yielding foams with low modulus and high strain recovery. It was found that when fibers were mixed into the foams, a small but insignificant increase in elastic modulus was achieved, and the foam structure became more homogeneous. SEM indicated that the compatibility between the fibers and the matrix was good, with fibers acting as bridges in the cell walls. IR spectroscopy and SE-HPLC revealed a relatively low degree of aggregation, which was highest in the presence of glycerol. Confocal laser scanning microscopy revealed distinct differences in HMW-glutenin subunits and gliadin distributions for all of the different samples. © 2011 American Chemical Society.


Moschou P.N.,Swedish University of Agricultural Sciences | Roubelakis-Angelakis K.A.,University of Crete
Journal of Experimental Botany | Year: 2014

Polyamines (PAs) have been considered as important molecules for survival. However, evidence reinforces that PAs are also implicated, directly or indirectly, in pathways regulating programmed cell death (PCD). Direct correlation of PAs with cell death refers to their association with particular biological processes, and their physical contact with molecules or structures involved in cell death. Indirectly, PAs regulate PCD through their metabolic derivatives, such as catabolic and interconversion products. Cytotoxic products of PA metabolism are involved in PCD cascades, whereas it remains largely elusive how PAs directly control pathways leading to PCD. In this review, we present and compare advances in PA-dependent PCD in animals and plants. © The Author 2013.


Kylberg G.,Uppsala University | Sintorn I.-M.,Swedish University of Agricultural Sciences
Eurasip Journal on Image and Video Processing | Year: 2013

Local binary pattern (LBP) operators have become commonly used texture descriptors in recent years. Several new LBP-based descriptors have been proposed, of which some aim at improving robustness to noise. To do this, the thresholding and encoding schemes used in the descriptors are modified. In this article, the robustness to noise for the eight following LBP-based descriptors are evaluated; improved LBP, median binary patterns (MBP), local ternary patterns (LTP), improved LTP (ILTP), local quinary patterns, robust LBP, and fuzzy LBP (FLBP). To put their performance into perspective they are compared to three well-known reference descriptors; the classic LBP, Gabor filter banks (GF), and standard descriptors derived from gray-level co-occurrence matrices. In addition, a roughly five times faster implementation of the FLBP descriptor is presented, and a new descriptor which we call shift LBP is introduced as an even faster approximation to the FLBP. The texture descriptors are compared and evaluated on six texture datasets; Brodatz, KTH-TIPS2b, Kylberg, Mondial Marmi, UIUC, and a Virus texture dataset. After optimizing all parameters for each dataset the descriptors are evaluated under increasing levels of additive Gaussian white noise. The discriminating power of the texture descriptors is assessed using tenfolded cross-validation of a nearest neighbor classifier. The results show that several of the descriptors perform well at low levels of noise while they all suffer, to different degrees, from higher levels of introduced noise. In our tests, ILTP and FLBP show an overall good performance on several datasets. The GF are often very noise robust compared to the LBP-family under moderate to high levels of noise but not necessarily the best descriptor under low levels of added noise. In our tests, MBP is neither a good texture descriptor nor stable to noise. © 2013 Kylberg and Sintorn; licensee Springer.


Zhao G.-L.,University of Stockholm | Hafren J.,Swedish University of Agricultural Sciences | Deiana L.,University of Stockholm | Cordova A.,University of Stockholm
Macromolecular Rapid Communications | Year: 2010

A simple and direct method for derivatization of solid polysaccharides is presented. The novel methodology is based on the combination of organic acid-catalyzed esterification or etherification and photochemical thiol-ene click derivatization of a heterogeneous polysaccharide. The solid cellulose was "organoclick" modified with aryl, alkyl and polyester groups, respectively. The modification allows for a highly modular and metal free surface modification of solid polysaccharides. (Figure Presented) © 2010 WILEY-VCH Verlag GmbH & Co. KGaA,.


This paper calculates the impacts of climatic change on cost effective nutrient management under the Water Framework Directive (WFD) for the eutrophic Mälar lake and Stockholm archipelago in south-eastern Sweden. This is carried out for two types of targets: actual nutrient reduction targets and water quality targets as suggested by WFD. Stochastic programming is applied where climatic changes are modelled as impacts on the mean and variability in nutrient loads and water quality. The results indicate significant impacts on abatement costs and associated nutrient policy design for both targets. Climatic change may under favourable conditions 'solve' the water quality problem by achieving the predetermined target without any need for policy instruments, but can also generate large increases in cleaning costs and required charge/subsidy schemes for the same target. The results also point to the importance of target setting, where water quality targets are more robust than nutrient reduction targets with respect to achievement under different climate change impacts. © 2009 Springer Science+Business Media B.V.


Jarvis N.,Swedish University of Agricultural Sciences
Science of the Total Environment | Year: 2016

Models used to assess leaching of pesticides to groundwater still rely on the sorption koc value, even though its limitations have been known for several decades, especially for soils of low organic carbon content (i.e. subsoils). This is mainly because the general applicability of any improved model approach that is also simple enough to use for regulatory purposes has not been demonstrated. The objective of this study was to test and compare alternative models of sorption that could be useful in pesticide risk assessment and management. To this end, a database containing the results of batch sorption experiments for pesticides was compiled from published studies in the literature, which placed at least as much emphasis on measurements in subsoil horizons as in topsoil. The database includes 785 data entries from 34 different published studies and for 21 different active substances. Overall, the apparent koc value, koc(app), roughly doubled as the soil organic carbon content decreased by a factor of ten. Nevertheless, in nearly half of the individual datasets, a constant koc value proved to be an adequate model. Further analysis showed that significant increases in koc(app) in subsoil were found primarily for the more weakly adsorbing compounds (koc valuesoc concept currently used in leaching models should therefore be replaced by an alternative approach that gives a more realistic representation of pesticide sorption in subsoil. The two alternative models tested in this study appear to have widespread applicability and are also simple enough to parameterize for this purpose. © 2015 Elsevier B.V.


Arora-Jonsson S.,Swedish University of Agricultural Sciences
Ecological Economics | Year: 2016

Culture, that for long had been a neglected concept in resilience thinking, has gained prominence in recent times, especially in the notion of ecocultures/ecocultural resilience to be achieved through transdisciplinary projects. In this paper, I conceptualize the relation of science with society and culture that resilience scholars propose as part of a larger agenda of the integration of science with different knowledge and epistemologies. In order to understand how resilience thinking relates to culture, I investigate the culture of resilience itself. Using the lens of cultural and science studies, I go back to the history and context of resilience and transdisciplinarity, examine some of the central tools and concepts in resilience thinking and its entanglements in the politics of the past and present. In light of the discussion, I argue that we need to 'situate' rather than 'integrate' our knowledge production. This entails not only recognizing our own culture but also being open to different ways of knowing and to be able to transgress resilience. Moving away from integration and embracing ambivalence and humility can open up to experimental practices and 'trading places' in order to engage with nature and others justly. © 2015 Elsevier B.V.


Walker L.R.,University of Nevada, Las Vegas | Wardle D.A.,Swedish University of Agricultural Sciences
Trends in Ecology and Evolution | Year: 2014

Ecologists have studied plant succession for over a hundred years, yet our understanding of the nature of this process is incomplete, particularly in relation to its response to new human perturbations and the need to manipulate it during ecological restoration. We demonstrate how plant succession can be understood better when it is placed in the broadest possible temporal context. We further show how plant succession can be central to the development of a framework that integrates a spectrum of ecological processes, which occur over time scales ranging from seconds to millions of years. This novel framework helps us understand the impacts of human perturbations on successional trajectories, ecosystem recovery, and global environmental change. © 2014 Elsevier Ltd.


Malmberg F.,Uppsala University | Luengo Hendriks C.L.,Swedish University of Agricultural Sciences
Pattern Recognition Letters | Year: 2014

The stochastic watershed is a method for unsupervised image segmentation proposed by Angulo and Jeulin (2007). The method first computes a probability density function (PDF), assigning to each piece of contour in the image the probability to appear as a segmentation boundary in seeded watershed segmentation with randomly selected seeds. Contours that appear with high probability are assumed to be more important. This PDF is then post-processed to obtain a final segmentation. The main computational hurdle with the stochastic watershed method is the calculation of the PDF. In the original publication by Angulo and Jeulin, the PDF was estimated by Monte Carlo simulation, i.e., repeatedly selecting random markers and performing seeded watershed segmentation. Meyer and Stawiaski (2010) showed that the PDF can be calculated exactly, without performing any Monte Carlo simulations, but do not provide any implementation details. In a naive implementation, the computational cost of their method is too high to make it useful in practice. Here, we extend the work of Meyer and Stawiaski by presenting an efficient (quasi-linear) algorithm for exact computation of the PDF. We demonstrate that in practice, the proposed method is faster than any previously reported method by more than two orders of magnitude. The algorithm is formulated for general undirected graphs, and thus trivially generalizes to images with any number of dimensions. © 2014 Elsevier B.V. All rights reserved.


Lofgren S.,Swedish University of Agricultural Sciences | Zetterberg T.,IVL Swedish Environmental Research Institute Ltd
Science of the Total Environment | Year: 2011

During the last two decades, there is a common trend of increasing concentrations of dissolved organic carbon (DOC) in streams and lakes in Europe, Canada and the US. Different processes have been proposed to explain this trend and recently a unifying hypothesis was presented, concluding that declining sulphur deposition and recovery from acidification, is the single most important factor for the long-term DOC concentration trends in surface waters. If this recovery hypothesis is correct, the soil water DOC concentrations should increase as well. However, long-term soil water data from Sweden and Norway indicate that there are either decreasing or indifferent DOC concentrations, while positive DOC trends have been found in the Czech Republic. Based on the soil water data from two Swedish integrated monitoring sites and geochemical modelling, it has been shown that depending on changes in pH, ionic strength and soil Al pools, the DOC solubility might be positive, negative or indifferent. In this study, we test the acidification recovery hypothesis on long-term soil water data (25 and 50cm soil depth) from 68 forest covered sites in southern Sweden, showing clear signs of recovery from acidification. The main aim was to identify potential drivers for the DOC solubility in soil solution by comparing trends in DOC concentrations with observed changes in pH, ionic strength and concentrations of Aln+. As in earlier Swedish and Norwegian studies, the DOC concentrations in soil water decreased or showed no trend. The generally small increases in pH (median <0.3 pH units) during the investigation period seem to be counterbalanced by the reduced ionic strength and diminished Al concentrations, increasing the organic matter coagulation. Hence, opposite to the conclusion for surface waters, the solubility of organic matter seems to decrease in uphill soils, as a result of the acidification recovery. © 2011 Elsevier B.V.


Garcia-Lledo A.,University of Girona | Vilar-Sanz A.,University of Girona | Trias R.,University of Girona | Hallin S.,Swedish University of Agricultural Sciences | Baneras L.,University of Girona
Water Research | Year: 2011

Removal of nitrogen is a key aspect in the functioning of constructed wetlands. However, incomplete denitrification may result in the net emission of the greenhouse gas nitrous oxide (N2O) resulting in an undesired effect of a system supposed to provide an ecosystem service. In this work we evaluated the genetic potential for N2O emissions in relation to the presence or absence of Phragmites and Typha in a free water surface constructed wetland (FWS-CW), since vegetation, through the increase in organic matter due to litter degradation, may significantly affect the denitrification capacity in planted areas. Quantitative real-time PCR analyses of genes in the denitrification pathway indicating capacity to produce or reduce N2O were conducted at periods of different water discharge. Genetic potential for N2O emissions was estimated from the relative abundances of all denitrification genes and nitrous oxide reductase encoding genes (nosZ). nosZ abundance was invariably lower than the other denitrifying genes (down to 100 fold), and differences increased significantly during periods of high nitrate loads in the CW suggesting a higher genetic potential for N2O emissions. This situation coincided with lower nitrogen removal efficiencies in the treatment cell. The presence and the type of vegetation, mainly due to changes in the sediment carbon and nitrogen content, correlated negatively to the ratio between nitrate and nitrite reducers and positively to the ratio between nitrite and nitrous oxide reducers. These results suggest that the potential for nitrous oxide emissions is higher in vegetated sediments. © 2011 Elsevier Ltd.


Gibb H.,La Trobe University | Gibb H.,CSIRO | Gibb H.,Swedish University of Agricultural Sciences | Parr C.L.,University of Oxford
Oecologia | Year: 2010

Habitat complexity can mediate key processes that structure local assemblages through effects on factors such as competition, predation and foraging behaviour. While most studies address assemblage responses to habitat complexity within one locality, a more global approach allows conclusions with greater independence from the phylogenetic constraints of the target assemblages, thus allowing greater generality. We tested the effects of natural and manipulated habitat complexities on ant assemblages from South Africa, Australia and Sweden, in order to determine if there were globally consistent responses in how functional measures of foraging success are regulated by habitat complexity. Specifically, we considered how habitat complexity affected ant foraging rates including the speed of discovery and rate of monopolisation. We also tested if habitat complexity affected the body size index, a size-related morphological trait, of ants discovering resources and occupying and monopolising the resources after 180 min. Ants were significantly slower to discover baits in the more complex treatments, consistent with predictions that they would move more slowly through more complex environments. The monopolisation index was also lower in the more complex treatments, suggesting that resources were more difficult to defend. Our index of ant body size showed trends in the predicted direction for complexity treatments. In addition, ants discovering, occupying and monopolising resources were smaller in simple than in complex natural habitats. Responses of discovering ants to resources in natural habitats were clear in only one of three regions. Consistent with our predictions, habitat complexity thus affected functional measures of the foraging success of ants in terms of measures of discovery and monopolisation rates and body size traits of successful ants. However, patterns were not always equally clear in manipulative and mensurative components of the study. © 2010 Springer-Verlag.


Kothawala D.N.,Uppsala University | Stedmon C.A.,Technical University of Denmark | Muller R.A.,Uppsala University | Weyhenmeyer G.A.,Uppsala University | And 2 more authors.
Global Change Biology | Year: 2014

Inland waters transport large amounts of dissolved organic matter (DOM) from terrestrial environments to the oceans, but DOM also reacts en route, with substantial water column losses by mineralization and sedimentation. For DOM transformations along the aquatic continuum, lakes play an important role as they retain waters in the landscape allowing for more time to alter DOM. We know DOM losses are significant at the global scale, yet little is known about how the reactivity of DOM varies across landscapes and climates. DOM reactivity is inherently linked to its chemical composition. We used fluorescence spectroscopy to explore DOM quality from 560 lakes distributed across Sweden and encompassed a wide climatic gradient typical of the boreal ecozone. Six fluorescence components were identified using parallel factor analysis (PARAFAC). The intensity and relative abundance of these components were analyzed in relation to lake chemistry, catchment, and climate characteristics. Land cover, particularly the percentage of water in the catchment, was a primary factor explaining variability in PARAFAC components. Likewise, lake water retention time influenced DOM quality. These results suggest that processes occurring in upstream water bodies, in addition to the lake itself, have a dominant influence on DOM quality. PARAFAC components with longer emission wavelengths, or red-shifted components, were most reactive. In contrast, protein-like components were most persistent within lakes. Generalized characteristics of PARAFAC components based on emission wavelength could ease future interpretation of fluorescence spectra. An important secondary influence on DOM quality was mean annual temperature, which ranged between -6.2 and +7.5 °C. These results suggest that DOM reactivity depends more heavily on the duration of time taken to pass through the landscape, rather than temperature. Projected increases in runoff in the boreal region may force lake DOM toward a higher overall amount and proportion of humic-like substances. © 2013 The Authors Global Change Biology Published by John Wiley & Sons Ltd.


Fries I.,Swedish University of Agricultural Sciences
Journal of Invertebrate Pathology | Year: 2010

Nosema ceranae is a microsporidian parasite described from the Asian honey bee, Apis cerana. The parasite is cross-infective with the European honey bee, Apis mellifera. It is not known when or where N. ceranae first infected European bees, but N. ceranae has probably been infecting European bees for at least two decades. N. ceranae appears to be replacing Nosema apis, at least in some populations of European honey bees. This replacement is an enigma because the spores of the new parasite are less durable than those of N. apis. Virulence data at both the individual bee and at the colony level are conflicting possibly because the impact of this parasite differs in different environments. The recent advancements in N. ceranae genetics, with a draft assembly of the N. ceranae genome available, are discussed and the need for increased research on the impacts of this parasite on European honey bees is emphasized. © 2009 Elsevier Inc. All rights reserved.


Lee M.-H.,National Taiwan University | Wang L.,Swedish University of Agricultural Sciences | Chang Z.-F.,National Taiwan University | Chang Z.-F.,National Yang Ming University
Nucleic Acids Research | Year: 2014

In quiescent fibroblasts, the expression levels of cytosolic enzymes for thymidine triphosphate (dTTP) synthesis are down-regulated, causing a marked reduction in the dTTP pool. In this study, we provide evidence that mitochondrial thymidylate synthesis via thymidine kinase 2 (TK2) is a limiting factor for the repair of ultraviolet (UV) damage in the nuclear compartment in quiescent fibroblasts. We found that TK2 deficiency causes secondary DNA double-strand breaks formation in the nuclear genome of quiescent cells at the late stage of recovery from UV damage. Despite slower repair of quiescent fibroblast deficient in TK2, DNA damage signals eventually disappeared, and these cells were capable of re-entering the S phase after serum stimulation. However, these cells displayed severe genome stress as revealed by the dramatic increase in 53BP1 nuclear body in the G1 phase of the successive cell cycle. Here, we conclude that mitochondrial thymidylate synthesis via TK2 plays a role in facilitating the quality repair of UV damage for the maintenance of genome integrity in the cells that are temporarily arrested in the quiescent state. © 2014 © The Author(s) 2014. Published by Oxford University Press.


Locke B.,Swedish University of Agricultural Sciences
Apidologie | Year: 2016

The Varroa destructor mite is the largest threat to apiculture worldwide and has been responsible for devastating losses of wild honeybee populations in Europe and North America. However, Varroa mite-resistant populations of A. mellifera honeybees have been reported and documented around the world with a variety of explanations for their long-term survival with uncontrolled mite infestation. This review synthesizes the work on naturally occurring survival to Varroa mites and discusses what these honeybee populations can signify for apiculture. © 2015, The Author(s).


Landberg R.,Swedish University of Agricultural Sciences | Naidoo N.,National University of Singapore | Van Dam R.M.,National University of Singapore
Current Opinion in Lipidology | Year: 2012

Purpose of Review: Endothelial dysfunction plays an important role in development and progression of atherosclerosis and may also contribute to the pathogenesis of type 2 diabetes. This review summarizes recent findings on the effects of vitamin D, antioxidant vitamins, polyphenols, polyphenol-rich foods, dietary component combinations and healthy diets on endothelial function. Recent Findings: Dietary patterns rich in fruit, vegetables, fish and nuts appear to have beneficial effects on endothelial function. With regard to specific foods, cacao and green tea consumption have been associated with improvement in endothelial function and this seems to be due to their flavan-3-ol (catechins and epigallocatechin gallate) content. The evidence for beneficial effects of other foods such as citrus fruit, apples and red wine is less consistent. Recent studies have also suggested beneficial effects of vitamin D and anthocyanins on endothelial function and have provided more insight into potential mechanisms underlying the effect of diet on endothelial function. Summary: The currently available evidence supports beneficial effects of various dietary compounds on endothelial function. However, in order to obtain strong evidence for relevant health effects that can be used for specific dietary recommendations, more long-term studies using well characterized diets/supplements in a large number of individuals are needed. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.


Ostman O.,Uppsala University | Drakare S.,Swedish University of Agricultural Sciences | Kritzberg E.S.,Lund University | Langenheder S.,Uppsala University | And 2 more authors.
Ecology Letters | Year: 2010

Microbial ecology has focused much on causes of between-site variation in community composition. By analysing five data-sets each of aquatic bacteria and phytoplankton, we demonstrated that microbial communities show a large degree of similarity in community composition and that abundant taxa were widespread, a typical pattern for many metazoan metacommunities. The regional abundance of taxa explained on average 85 and 41% of variation in detection frequency and 58 and 31% of variation in local abundances for bacteria and phytoplankton, respectively. However, regional abundance explained less variation in local abundances with increasing environmental variation between sites within data-sets. These findings indicate that the studies of microbial assemblages need to consider similarities between communities to better understand the processes underlying the assembly of microbial communities. Finally, we propose that the degree of regional invariance can be linked to the evolution of microbes and the variation in ecosystem functions performed by microbial communities. © 2009 Blackwell Publishing Ltd/CNRS.


de Miranda J.R.,Swedish University of Agricultural Sciences | Genersch E.,Institute for Bee Research
Journal of Invertebrate Pathology | Year: 2010

Deformed wing virus (DWV; Iflaviridae) is one of many viruses infecting honeybees and one of the most heavily investigated due to its close association with honeybee colony collapse induced by Varroa destructor. In the absence of V. destructor DWV infection does not result in visible symptoms or any apparent negative impact on host fitness. However, for reasons that are still not fully understood, the transmission of DWV by V. destructor to the developing pupae causes clinical symptoms, including pupal death and adult bees emerging with deformed wings, a bloated, shortened abdomen and discolouration. These bees are not viable and die soon after emergence. In this review we will summarize the historical and recent data on DWV and its relatives, covering the genetics, pathobiology, and transmission of this important viral honeybee pathogen, and discuss these within the wider theoretical concepts relating to the genetic variability and population structure of RNA viruses, the evolution of virulence and the development of disease symptoms. © 2009 Elsevier Inc. All rights reserved.


Taylor R.P.,University of Oregon | Spehar B.,University of New South Wales | van Donkelaar P.,University of Oregon | Hagerhall C.M.,Swedish University of Agricultural Sciences
Frontiers in Human Neuroscience | Year: 2011

Fractals have been very successful in quantifying the visual complexity exhibited by many natural patterns, and have captured the imagination of scientists and artists alike. Our research has shown that the poured patterns of the American abstract painter Jackson Pollock are also fractal. This discovery raises an intriguing possibility - are the visual characteristics of fractals responsible for the long-term appeal of Pollock's work? To address this question, we have conducted 10 years of scientific investigation of human response to fractals and here we present, for the first time, a review of this research that examines the inter-relationship between the various results. The investigations include eye tracking, visual preference, skin conductance, and EEG measurement techniques. We discuss the artistic implications of the positive perceptual and physiological responses to fractal patterns. © 2011 Taylor, Spehar, Van Donkelaar and Hagerhall.


Hansson K.,Swedish University of Agricultural Sciences | Helmisaari H.-S.,University of Helsinki | Sah S.P.,Finnish Forest Research Institute | Lange H.,Norwegian Forest And Landscape Institute
Forest Ecology and Management | Year: 2013

Fine roots contribute to net primary production in forests, but knowledge of fine root longevity and turnover is still incomplete and limited to few tree species. In this study, we used minirhizotrons to compare fine root biomass, longevity and turnover of Pinus sylvestris L., Betula pendula Roth and Picea abies (L) Karst. in southern Sweden. Minirhizotron tubes were installed in 2006 and root images were taken in 2007-2010. Soil cores were used to estimate fine root biomass. Soil samples were taken from the humus layer and from 0 to 10. cm, 10 to 20. cm and 20 to 30. cm depth in the mineral soil. Only images from the humus layer and the upper 10. cm of mineral soil were included in root analysis. Spruce has a higher aboveground production than pine and birch in southern Sweden and this was reflected in larger fine root biomass as well as higher fine root biomass production. The annual tree fine root biomass production (humus and 0-30cm in mineral soil) was 73, 78 and 284gm-2 in pine, birch and spruce stands, respectively. Thicker fine roots tended to live longer. The majority of the fine roots were thinner than 0.5mm in diameter, with a turnover rate (KM) of 0.4year-1. When comparing all fine roots, i.e. all roots 0-2mm, pine had the highest longevity, 1120days, compared with 900days for spruce and 922days for birch (KM). © 2013 Elsevier B.V.


Schorkopf D.L.P.,Swedish University of Agricultural Sciences
Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology | Year: 2016

In highly social hymenopteran societies, males mainly serve reproductive purposes. Semiochemicals enable the different hymenopteran sexes and castes to communicate with each other and to coordinate important functions within colonies. I hereby show that sexual dimorphism in meliponine bees incorporates the alarm and defence communication system. I chemically analysed the mandibular glands of Scaptotrigona aff. depilis using GCMS methods and conducted behavioural experiments in both males and female workers using cephalic and mandibular gland extracts. In addition, behaviour studies with male cephalic extracts were also conducted in Scaptotrigona bipunctata and Partamona cupira. Males and female worker bees showed differences in the content of the mandibular glands, which are responsible for alarm communication in meliponines. Males never attacked but usually fled when confronted with the mandibular gland extract content of other conspecific males or females. Interestingly, however, meliponine males were still able to raise alarm and to induce substantial amounts of aggression at nest entrances, which is different from the much better known and studied honey bees. Potential reasons are briefly discussed. © 2016 Springer-Verlag Berlin Heidelberg


Chorell E.,Umea University | Svensson M.B.,Umea University | Moritz T.,Swedish University of Agricultural Sciences | Antti H.,Umea University
Molecular BioSystems | Year: 2012

An excessive energy intake combined with a low level of physical activity induces detrimental processes involved in disease development, e.g. type 2 diabetes and cardiovascular disease. However the underlying mechanisms for regulation of metabolic capacity and fitness status remain unclear. Metabolomics involves global studies of the metabolic reactions in an organism or cell. Thus hypotheses regarding biochemical events can be generated to increase the understanding of disease development and thereby aid in the development of novel treatments or preventions. We present the first standardized intervention study focusing on characterizing the human metabolome in relation to moderate differences in cardiorespiratory fitness. Gas chromatography-time of flight/mass spectrometry (GC-TOF/MS) was used to characterize 460 plasma samples from 27 individuals divided into two groups based on physical fitness level (VO 2max). Multi- and univariate between group comparisons based on 197 metabolites were carried out in samples collected at rest prior to any intervention, over time following a nutritional load or a standardized exercise scheme, with and without nutritional load. We detected decreased levels of gamma-tocopherol (GT), a vitamin E isomer, in response to a high fitness level, whereas the opposite was seen for the alpha isomer (AT). In addition, the high fitness level was associated with elevated ω3-PUFA (DHA, 22:6ω3) and a decrease in ω6-PUFA (18:2ω6) as well as in saturated (16:0, 18:0), monounsaturated (18:1) and trans (16:1) fatty acids. We thus hypothesize that high fitness status induces an increased cardiorespiratory inflammatory and antioxidant defense system, more prone to deal with the inflammatory response following exercise and nutrition intake. © 2012 The Royal Society of Chemistry.


Fischer K.,Swedish University of Agricultural Sciences
Research Policy | Year: 2016

Poverty reduction during the Asian Green Revolution has been attributed to the inherent scale neutrality of new crop varieties making them equally beneficial to small-scale and large-scale farmers. The term 'scale-neutral' is now reappearing in debates on agricultural development in Africa with claims that crop technology is inherently scale-neutral and that African smallholders will significantly benefit from new crop varieties not specifically developed for their contexts. Using a social shaping of technology (SST) perspective and the concept of biological embeddedness, this paper critically examines whether it is helpful to describe crop technology as scale neutral when drawing lessons from the Asian Green Revolution about how new crop technology can be of benefit to African smallholders. The paper describes how political commitment, rather than inherently scale-neutral crops, was central for the outcome of the Asian Green Revolution. It also highlights that while the effects of crop biology are often disregarded in adoption studies, biology significantly affected the ability of Green Revolution crop technology to benefit smallholders, and continues to do so today. Using maize and GM crops as examples, this paper suggests that GM crops in their current form have reinforced a technological trajectory established with hybrid technology and directed it away from smallholder practices and agroecologies. Consequently, describing crop technology as inherently scale-neutral is not helpful for understanding how crop technology works in Africa today and prevents important lessons being learned from the Asian Green Revolution. © 2016 Elsevier B.V. All rights reserved.


Ellison D.,Swedish University of Agricultural Sciences
Ecological Engineering | Year: 2016

In this proof of concept paper, we address the potential role of forests and vegetation cover as an adaptation tool. In contrast to work addressing the carbon benefits of afforestation, we highlight the potential usefulness of forests as major contributors to the water cycle. Integrating water and carbon cycle benefits into a common objective enhances discussions about the role and value of forests. Herein, we describe a method for increasing regional precipitation in semi-arid environments, thereby potentially helping to increase scarce water resources. The approach capitalizes on observed interactions between forest cover and the hydrologic cycle, with the express aim of returning much needed water resources to an increasingly vulnerable region. The natural processes behind "precipitation recycling" (PR), and vegetation based cross continental transport of atmospheric moisture form the core of this solution. Induced precipitation recycling (IPR) initiates these processes by irrigating afforested land using locally available surplus water. This paper discusses the underlying processes and a proposed demonstration project that functions as both a "proof of concept" and a research testing ground, providing potential validation for promoting future expansion to the wider region. The proposed IPR project utilizes treated wastewater and surplus storm run-off, thus averting additional burdens on the existing water supply, while performing additionally valuable environmental and ecosystem services. IPR provides an alternative approach to supplement existing and typically far costlier plans to address regional water shortages and handle wastewater treatment. The proposed integrated solution would not only contribute positively to regional water supply, but would also provide additional eco-system services and end-products that add value and utility, thereby improving the project's potential economic viability. This project should be of particular interest to land use and water management planners in the Los Angeles Basin area for whom it is conceived, as well as to those along much of the coastal region in California where climate change-driven drought cycles have been increasing in length and intensity. © 2016 Elsevier B.V.


Tarka M.,Lund University | Akesson M.,Swedish University of Agricultural Sciences | Hasselquist D.,Lund University | Hansson B.,Lund University
American Naturalist | Year: 2014

Intralocus sexual conflict (ISC) occurs when males and females have different adaptive peaks but are constrained fromevolving sexual dimorphism because of shared genes. Implications of this conflict on evolutionary dynamics in wild populations have not been investigated in detail. In comprehensive analyses of selection, heritability, and genetic correlations, we found evidence for an ISC over wing length, a key trait for flight performance and migration, in a long-term study of wild great reed warblers (Acrocephalus arundinaceus). We found moderate sexual dimorphism, high heritability, moderate sexually antagonistic selection, and strong positive crosssex genetic correlation in wing length, together supporting the presence of ISC. A negative genetic correlation between male wing length and female fitness indicated that females inheriting alleles for longer wings from their male relatives also inherited lower fitness. Moreover, cross-sex genetic correlations imposed constraint on the predicted microevolutionary trajectory of wing length (based on selection gradients), especially in females where the predicted response was reversed. The degree of sexual dimorphism in wing length did not change over time, suggesting no sign of conflict resolution. Our study provides novel insight into how an ISC over a fitness trait can affect microevolution in a wild population under natural selection. © 2013 by The University of Chicago.


Stenberg J.A.,Swedish University of Agricultural Sciences
Insect Science | Year: 2012

The parasitoid Asecodes mento (Walker, 1839) (Hymenoptera: Eulophidae) is the most important biocontrol agent of the strawberry leaf beetle Galerucella tenella (L.) (Coleoptera: Chrysomelidae) in northern Europe. Here, I investigated whether natural parasitism in organic strawberry plantations was affected by the presence of the alternative host plant meadowsweet (Filipendula ulmaria), and whether parasitism rates differed between plantations of different ages (6 to 79 years). I also investigated whether parasitoid brood size, body size and sex ratio differed between the two host plants in the field. Parasitism was very low (0%) in newly established plantations and increased to a plateau (∼40%) in fields where strawberries had been grown for approximately 20 years or longer. Such an extended colonization process is unacceptable for commercial growers. It would thus be desirable to find a method to catalyze parasitoid population buildup in young plantations. Parasitoid brood sizes were larger in beetles collected from meadowsweet, while body size and sex ratio did not differ between parasitoids collected from the two plants. These findings suggest that meadowsweet can export parasitoids to neighboring strawberry fields. Although this is a possibility, I did not find any significant differences in parasitism rates between isolated strawberry fields and fields adjacent to meadowsweet stands, indicating that effects of local vegetation are small on parasitism rates. Releasing parasitoids in newly established strawberry plantations may be a better strategy for quickly obtaining high parasitism than intercropping with meadowsweet. © 2012 Institute of Zoology, Chinese Academy of Sciences.


El-Mogy M.M.,Cairo University | Alsanius B.W.,Swedish University of Agricultural Sciences
Food Control | Year: 2012

The inhibitory effects of cassia oil on the human pathogen . Escherichia coli serotype O157:H7 and the plant pathogen . Botrytis cinerea were tested . in vitro at different concentrations (200-800 ppm). Cassia oil exhibited antibacterial and antifungal activity against both pathogens. Cassia oil at 400-800 ppm inhibited the growth of . E. coli O157:H7 . in vitro and on the surface of treated strawberries. Cassia oil also completely inhibited the growth of . B. cinerea at 400-800 ppm. Spore germination and germ tube elongation of the pathogens in potato dextrose broth were strongly inhibited in the presence of 100 ppm cassia oil. Cassia oil at all concentrations reduced the percentage of decayed strawberries. Experiments on reducing the development of natural decay in strawberries gave similar results. None of the quality parameters tested (colour, total soluble solids, pH, total acidity and ascorbic acid) was affected by cassia oil treatment. Storage experiments on strawberry showed that the percentage weight loss was reduced by cassia oil treatment. Hence, cassia oil could be an alternative to synthetic chemicals for controlling human and plant pathogens on fruits such as strawberries during postharvest and storage. © 2012 Elsevier Ltd.


Grandin U.,Swedish University of Agricultural Sciences
Ambio | Year: 2011

The aim was to describe spatiotemporal patterns of colonization of spruce branches by algae and lichens and the relationship with decreasing deposition of N and S. Coverage was estimated annually over 10 years for four Swedish Integrated Monitoring catchments with varying deposition levels. Initial hypotheses were that algal coverage would be positively correlated with deposition and that lichen coverage would be negatively correlated with S and positively with N deposition. Data were analyzed using regression, ANOVA, and partial least square regression. The results showed a temporal decrease in the coverage of algae but an increase in colonization rates, while lichens showed less uniform patterns. Within catchments, algae and lichen coverages were positively correlated with mainly S deposition. Across catchments, coverage of algae increased, while the coverage of lichens decreased with increasing N and S deposition. Colonization rates of both algae and lichens showed weak correlations with both spatial and temporal trends in N and S deposition. Thus, while N and S deposition had an effect on the colonization and coverage of algae and lichens, other factors are also important. © 2011 Royal Swedish Academy of Sciences.


Grandin U.,Swedish University of Agricultural Sciences
Ambio | Year: 2011

The aims of this study were to investigate spatial patterns and temporal changes in understorey vegetation at four forest catchments forming a depositional gradient. Inventories of the bottom and field layers were carried out in the 1990s and repeated after 514 years, depending on catchment. It was hypothesized that changes and patterns in ground vegetation would be related to changes and patterns in N and S deposition. The data were analyzed using Ellenberg indices and multivariate methods. All catchments showed temporal changes in species composition. Analyses of the bottom layer were confounded by a change of field staff, but after accounting for this observer effect, differences in species composition between the catchments remained. Within catchments, the changes in species composition were unrelated to N or S deposition. Relationships between environmental factors, expressed as Ellenberg indices, and compositional patterns differed between catchments although Ellenberg indices showed small temporal changes. © 2011 Royal Swedish Academy of Science.


Langvall O.,Swedish University of Agricultural Sciences
Scandinavian Journal of Forest Research | Year: 2011

A model including site-specific microclimate-affecting properties of a forest regeneration area together with seedling characteristics was used to evaluate the accumulated risk of frost damage to Norway spruce (Picea abies (L.) Karst.) seedlings. Climate change in Sweden was simulated on the basis of the regional climate model RCA3. The daily average temperature, the driving factor for bud burst in the model, was adjusted using the difference between the mean of the climate model data for the years 1961-1990 and 2036-2065. The model was run for a highly frost prone, clear-cut site in which bare-rooted Norway spruce seedlings of mid-Swedish provenance were planted. Alternate runs were conducted with data for containerized seedlings and seedlings of Belarusian origin. The study showed that bud burst will occur at earlier dates throughout Sweden in the period 2036-2065 if the climate changes according to either of the climate scenarios examined, compared to the reference period 1961-1990. Furthermore, the risk of damage to Norway spruce seedlings as a result of frost events during summer will increase in southern Sweden and be unaffected or decrease in northern Sweden. The risk of frost damage was exacerbated in containerized seedlings, while the risk was lower for the seedlings of Belarusian provenance when compared with bare-rooted seedlings or seedlings of mid-Swedish origin. © 2011 Taylor & Francis.


Norell K.,Swedish University of Agricultural Sciences
Computers and Electronics in Agriculture | Year: 2011

The quality of wood can be analyzed using annual ring width. At Swedish sawmills, this is performed using manual inspection for grading purpose. Here a completely automatic method for counting the number of annual rings on log end faces is described and evaluated. The method is applied and tested using images from Pinus sylvestris end faces acquired in online sawmill production with a camera mounted above a conveyor belt. Completely untreated end faces were captured, as well as newly sawn ones. The proposed method includes preprocessing, pith detection and counting the number of rings in two regions of the end face. A new method to remove marks from uneven sawing is presented as a part of the preprocessing steps. The evaluation shows that the suggested automatic method performs as well as the manual measurements that are the method used for measuring today. © 2010 Elsevier B.V.


Jansson T.,Swedish University of Agricultural Sciences | Heckelei T.,University of Bonn
Journal of Agricultural Economics | Year: 2011

This article estimates behavioural parameters of the quadratic regional supply models in the modelling system CAPRI. Using the time-series data in the CAPRI database, we directly estimate the optimality conditions using a Bayesian highest posterior density estimator. After discarding regions with insufficient data, parameters for up to 23 crop production activities with related inputs, outputs, prices and behavioural functions are estimated for 219 regions in EU-27. The results are systematically compared with the outcomes of other studies. For crop aggregates (e.g. cereals, oilseeds, etc.) at the national level, the estimated own price elasticities of supply are found to be in a plausible range. On a regional level and for individual crops, the picture is much more diverse. As far as we know, there is no other study of similar regional and product coverage. © 2010 Blackwell Publishing Ltd.


Zydor A.,Tyndall National Institute | Kessler V.G.,Swedish University of Agricultural Sciences | Elliott S.D.,Tyndall National Institute
Physical Chemistry Chemical Physics | Year: 2012

It is a common finding that titanocene-derived precursors do not yield TiO 2 films in atomic layer deposition (ALD) with water. For instance, ALD with Ti(OMe) 4 and water gives 0.5 Å/cycle, while TiCp*(OMe) 3 does not show any growth (Me = CH 3, Cp* = C 5(CH 3) 5). From mass spectrometry we found that Ti(OMe) 4 occurs in the gas phase practically exclusively as a monomer. We then used first principles density functional theory (DFT) to model the ALD reaction sequence and find the reason for the difference in growth behaviour. Both precursors adsorb initially via hydrogen-bonding. The simulations reveal that the Cp* ligand of TiCp*(OMe) 3 lowers the Lewis acidity of the Ti centre and prevents its coordination to surface O ('densification') during both of the ALD pulses. The effect of Cp* on Ti seems to be both steric (full coordination sphere) and electronic (lower electrophilicity). This crucial step in the sequence of ALD reactions is therefore not possible in the case of TiCp*(OMe) 3 + H 2O, which means that there is no deposition of TiO 2 films. © 2012 the Owner Societies.


Kleijn D.,Wageningen University | Rundlof M.,Lund University | Rundlof M.,Swedish University of Agricultural Sciences | Scheper J.,Wageningen University | And 2 more authors.
Trends in Ecology and Evolution | Year: 2011

Biodiversity continues to decline, despite the implementation of international conservation conventions and measures. To counteract biodiversity loss, it is pivotal to know how conservation actions affect biodiversity trends. Focussing on European farmland species, we review what is known about the impact of conservation initiatives on biodiversity. We argue that the effects of conservation are a function of conservation-induced ecological contrast, agricultural land-use intensity and landscape context. We find that, to date, only a few studies have linked local conservation effects to national biodiversity trends. It is therefore unknown how the extensive European agri-environmental budget for conservation on farmland contributes to the policy objectives to halt biodiversity decline. Based on this review, we identify new research directions addressing this important knowledge gap. © 2011 Elsevier Ltd.


Makela M.,Swedish University of Agricultural Sciences | Benavente V.,University of Alicante | Fullana A.,University of Alicante
Applied Energy | Year: 2015

Although hydrothermal carbonization of biomass components is known to be mainly governed by reaction temperature, consistent reports on the effect and statistical significance of process conditions on hydrochar properties are still lacking. The objective of this research was to determine the importance and significance of reaction temperature, retention time and solid load on the properties of hydrochar produced from an industrial lignocellulosic sludge residue. According to the results, reaction temperature and retention time had a statistically significant effect on hydrochar ash content, solid yield, carbon content, O/C-ratio, energy densification and energy yield as reactor solid load was statistically insignificant for all acquired models within the design range. Although statistically significant, the effect of retention time was 3-7 times lower than that of reaction temperature. Predicted dry ash-free solid yields of attained hydrochar decreased to approximately 40% due to the dissolution of biomass components at higher reaction temperatures, as respective oxygen contents were comparable to subbituminous coal. Significant increases in the carbon contents of hydrochar led to predicted energy densification ratios of 1-1.5 with respective energy yields of 60-100%. Estimated theoretical energy requirements of carbonization were dependent on the literature method used and mainly controlled by reaction temperature and reactor solid load. The attained results enable future prediction of hydrochar properties from this feedstock and help to understand the effect of process conditions on hydrothermal treatment of lignocellulosic biomass. © 2015 Elsevier Ltd.


Pacurar D.I.,Umea University | Perrone I.,Umea University | Perrone I.,Swedish University of Agricultural Sciences | Bellini C.,Umea University | Bellini C.,French National Institute for Agricultural Research
Physiologia Plantarum | Year: 2014

Vegetative propagation of economically important woody, horticultural and agricultural species rely on an efficient adventitious root (AR) formation. The formation of ARs is a complex genetic trait regulated by the interaction of environmental and endogenous factors among which the phytohormone auxin plays an essential role. This article summarizes the current knowledge related to the intricate network through which auxin controls adventitious rooting. How auxin and recently identified auxin-related compounds affect AR formation in different plant species is discussed. Particular attention is addressed to illustrate how auxin has a central role in the hormone cross-talk leading to AR development. In parallel, we describe the molecular players involved in the control of auxin homeostasis, transport and signaling, for a better understanding of the auxin action during adventitious rooting. © 2014 Scandinavian Plant Physiology Society.


Ekstrom G.,Former Pesticide Regulator | Ekbom B.,Swedish University of Agricultural Sciences
Critical Reviews in Plant Sciences | Year: 2011

This text combines two basically different views on pest control namely the scientific researcher's view on pest control and the pesticide regulator's views on pesticide control aiming at a common and pragmatic ecological approach. A set of practicable 'tools' are discussed that can be used to monitor and reduce environmental impact on agro-ecosystems where the ultimate goal is to move towards a more environmentally sustainable agriculture. General principles governing farming systems and pest control strategies are illustrated with pesticide use and pesticide risk reduction measures in coffee and rice cultivations. Adaptive pest control based on Integrated Pest Management with a rational use of pesticides as a last resort is suggested to be the most viable way forward. © Taylor & Francis Group, LLC.


Mensah J.T.,Swedish University of Agricultural Sciences
Energy Policy | Year: 2014

Following the recent global economic downturn, attention has gradually shifted towards emerging economies which have experienced robust growth amidst sluggish growth of the world economy. A significant number of these emerging economies are in Africa. Rising growth in these economies is associated with surging demand for energy to propel the engines of growth, with direct implications on emissions into the atmosphere. Further, these economies are constantly being shaped by series of structural reforms with direct and indirect effects on growth, demand for energy, etc. To this end, this paper examines the causal dynamics among energy use, real GDP and CO2 emissions in the presence of regime shifts in six emerging African economies using the Gregory and Hansen (1996a). J. Econ. 70, 99-126 threshold cointegration and the Toda and Yamamoto (1995). J. Econometrics. 66, 225-250 Granger causality techniques. Results confirm the presence of regime shift effects in the long run inter-linkages among energy use, real GDP and CO2 emissions in the countries considered, thus indicating that structural changes have both economic and environmental effects. Hence, integration of energy and environmental policies into development plans is imperative towards attaining sustainable growth and development. © 2014 Elsevier Ltd.


Larsbo M.,Swedish University of Agricultural Sciences
Vadose Zone Journal | Year: 2011

Variations in the concentrations of naturally occurring isotopes in rainfall provide a "continuous" signal that has the potential to generate more information on how weather conditions control solute transport than traditional field tracer experiments. An isotopically distinct rainfall event can be rapidly transferred through the system when preferential flow occurs. The objective of this study was to develop and test an approach for analyzing how rainfall and soil moisture control preferential transport to tile drains. An episodic solute transit time distributions model that accounts for these effects was developed. The model was tested on artificial data (daily values of tile drain discharge and 18O concentrations in the drainage water) generated by the MACRO model for soils with different potentials for preferential flow. The results showed that the transit time model gave an excellent fit to the artificial data for the soil with a high potential for preferential flow. The dynamics of the preferential flow events were well captured also for the soil with medium potential for preferential flow but the magnitude was sometimes poorly simulated. Once the model parameter values have been determined, the model can be used to calculate the amount and distribution with time of preferential flow to tile drains for all daily rainfall data. Model calculations integrate the soil's potential for preferential flow and the effects of weather conditions and are, therefore, highly relevant as site-specific indicators for the risk of preferential leaching of agrochemicals. The approach needs to be evaluated against real field data, however, before its usefulness can be established. © Soil Science Society of America.


Edenius L.,Swedish University of Agricultural Sciences
Ornis Fennica | Year: 2011

Effects of wildfire on forest birds have rarely been studied in Fennoscandia. Hence, birds were surveyed three years after fire at two large areas that were not subjected to salvage logging, in northern Sweden. The 300- and 440-ha burns and surrounding forests were dominated by Scots pine and Norway spruce, respectively. Closed-nest breeders and ground-feeding insectivores were more abundant within the burns than in the surrounding forests, whereas ground- and shrub-breeders were nearly equally abundant in the burns and in unburned forests. Redpoll and Tree Pipit were more common within than outside the burns. Birds feeding on insects in the air and the Redstart were more abundant in burned than in unburned spruce-dominated forest but no such difference was found in pine-dominated forest, suggesting that the short-term effects of wildfire on these birds were stronger in spruce-dominated forest than in pine-dominated forest. A contributing factor might be that crown fire killed most trees in the spruce-dominated burn, but most of the large trees survived the ground fire in the pine-dominated burn.


Jarnemo A.,Swedish University of Agricultural Sciences
Journal of Ethology | Year: 2011

Breeding dispersal can be of significant ecological and evolutionary importance. Yet, it is seldom considered in mammals. I present data on male red deer (Cervus elaphus) movements between sub-populations in southern Sweden during the rut. I investigated whether these movements could be breeding dispersal driven by mate competition. During the ruts of 1998-2009, I recorded 91 movements of males. The longest movement distance was 18.5 km. Dispersal was not restricted to yearlings or sub-adults, but also observed among adult stags. Of 91 movements observed, 7 were made by yearlings, 46 by sub-adults and 38 by adults. There was a significant move among yearlings and sub-adults towards areas with a higher ratio of females/adult males and towards areas with more females. The movements between rutting areas thereby seemed driven by sexual competition. © 2011 Japan Ethological Society and Springer.


Ohlsson K.E.A.,Swedish University of Agricultural Sciences
Soil Biology and Biochemistry | Year: 2011

For measurement of the time lag between photosynthesis and CO2 efflux from soil, the carbon isotope pulse-labeling technique is considered as the most suitable. However, an interference from the abiotic tracer CO2 component is identified as a key difficulty for obtaining accurate results with this technique. Guidelines on how to reduce this interference are therefore urgently needed. The flux of abiotic 13CO2 tracer into soil during the labeling stage, and its return to atmosphere during the monitoring stage was modeled numerically, and the labeling stage also analytically. The controls of the abiotic interference were investigated using these models. The amount of the abiotic tracer component and the time distribution of its rate of return to the atmosphere, were predicted by these models. The main model parameters were Dm (=the ratio between the soil 13CO2 diffusivity and the retardation factor), and the 13CO2 concentration at the soil-atmosphere interface during the labeling stage (S13), while background 13CO2 soil production parameters were unnecessary. The presented models guide the selection of experimental parameters for minimization of the abiotic interference. With parameterization for a particular case, the present numerical model provides a preliminary order-of-magnitude estimate of the abiotic component, which would indicate if this interference is of significance. © 2010 Elsevier Ltd.


Muller C.E.,Swedish University of Agricultural Sciences
Applied Animal Behaviour Science | Year: 2011

The influence of plant maturity at harvest of haylage on equine ingestion times and ingestive behaviour was studied. Haylage was harvested at three different occasions: June, July and August, from the primary growth of the same grass-dominated sward. Twelve adult horses of European warmblood type were divided into three groups and used in a change-over experiment with three periods, so that all horses had been fed each of the three haylages at the end of the experiment. Measurements of eating time (min/kg dry matter (DM)), chewing rate (chews/min), swallowing rate (swallowing/min) and the number of chews/swallowing were made for five consecutive days in each period for each horse. Haylages were analysed for chemical composition and nutritive value. Results showed that horses ingested haylage harvested in June (29 min/kg DM) faster (P<. 0.0001) than haylages harvested in July and August (37 and 36 min/kg DM, respectively). Pearson's correlation coefficients were calculated between eating time and ingestive data and between eating time/ingestive data and composition of haylages. The highest correlation coefficient (0.94***) was found between eating time and number of chews/kg DM. The highest correlation coefficient related to fibre composition of haylage and ingestive behaviour was 0.66 (***), and was found between eating time and content of neutral detergent fibre in the haylage. Similar correlation coefficients were present for eating time and other variables describing fibre content (content of acid detergent fibre and lignin) in the haylage. In conclusion, a late harvest date of haylage may prolong total eating times for adult horses, partly due to a longer eating time per kg dry matter for such haylage, but also due to the generally higher feeding level needed to cover the energy and nutrient requirements of the horse when late harvested forages are used in forage-only diets. © 2011 Elsevier B.V.


Keskitalo E.C.H.,Swedish University of Agricultural Sciences | Keskitalo E.C.H.,Umea University
Forests | Year: 2011

It is only relatively recently that national adaptation strategies have begun to develop measures by which forestry can adapt to climate change; often those measures opt to use a relatively general strategy for coping under conditions of disturbance. Particularly in states using intensive forest management, such as Sweden, this approach marks a departure from current strategies for achieving maximum yield. In other countries, however, where the economic output from forestry is less significant and interests such as biodiversity, local use and tourism, may figure more prominently, the conditions for developing risk-based forest management may be more manifest. This study reviews literature on adaptations in forest management, and analyzes country reports submitted as part of an EU27 project. The study concludes that the diverse prerequisites and policies of states have seldom been reflected in the design of adaptation management actions to date. © 2011 by the authors; licensee MDPI, Basel, Switzerland.


Raitio K.,Swedish University of Agricultural Sciences
Forest Policy and Economics | Year: 2013

The purpose of the paper is to present an analytical framework for studying conflict management processes. The paper draws on discursive approaches to new institutional theory in integrating three inter-related elements of conflict management: collaborative practices; formal and informal institutions; and the ways the policy issues are understood and communicated (framed) by the different actors in contested situations. The Discursive Institutional Conflict Management Analysis framework (DICMA) draws focus to the interaction between these three elements during conflict management efforts. It also helps to identify challenges related to each of the elements when improving conflict management, and contributes to formulating necessary policy reforms.A case study looking at the management of old-growth forest conflicts on public land in Finland is used to illustrate the applicability of the approach. The empirical analysis shows that the 'old new institutionalist' analysis is useful in explaining how history shapes the paths of the institutional reforms, how informal norms affect behaviour of natural resource management agencies, and how institutional structures create counterproductive incentive structures for the conflict management practices. However it takes the discursive approach, here applied through frame analysis, to understand the responses and strategies of natural resource management agencies in the face of the institutional challenges. Institutional and frame analyses in combination shed light to the logic behind the state forest agency's seemingly unproductive approaches to the conflicts. © 2012 Elsevier B.V.


Delin S.,Swedish University of Agricultural Sciences | Stromberg N.,SP Technical Research Institute of Sweden
European Journal of Soil Science | Year: 2011

The choice of manure application technique can affect both the spatial distribution of ammonium in soil and net nitrogen (N) mineralization, and thereby N availability to crops. In this study we compared net N mineralization and spatial ammonium distribution after different degrees of incorporation of solid chicken manure and cattle slurry into soil. Ammonium-specific fluorescing optodes were assembled with manure applied to soil in closed chambers and the spatial distribution of ammonium in different treatments was measured for 2 weeks. The results indicated that much ammonium from the manures was quickly adsorbed to clay particles. Consequently, the ammonium concentration in the soil solution was threefold higher in the sandy soil than in the clay soil studied. Ammonium was distributed over a larger soil volume from manure applied below the soil surface than from manure applied above. Because the optodes excluded ammonium adsorbed to soil particles, net N mineralization was instead studied in separate incubations using extraction with potassium chloride solution for determination of ammonium and nitrate. When manure was kept concentrated in lumps rather than being mixed with soil, nitrate levels were about five times smaller after 1 week and 5-10% more of the manure N occurred as mineral N after 2 weeks. There were no differences in net N mineralization between surface application and subsurface incorporation. In this study a new technique to visualize and measure ammonium patterns around manure in soil proved to be useful for evaluating ammonium distribution and adsorption, but net N mineralization required incubations. © 2010 The Authors. Journal compilation © 2010 British Society of Soil Science.


Johansson T.,Swedish University of Agricultural Sciences
Scandinavian Journal of Forest Research | Year: 2011

Site index (SI) curves for H20 (dominant height at 20 years total age) were constructed using growth data from 64 hybrid poplars (Populus spp.) growing in 33 stands planted on farmland in Sweden (Lat. 55-60°N). The mean age of the stands was 24 years (range 14-45), the mean density 993 stems ha-l (155-3493), and the mean diameter at breast height (outside bark) 24 cm (10-45). SI curves fitted for H20 at total age were well in accordance with the SI curves presented by other studies. A number of dynamic equations for modeling top-height growth from total age were assessed. A generalized algebraic difference approach (ADA) model derived by Cieszewski performed best. The model explained 98% of the observed variation in height development and exhibited no apparent bias across the range of predicted site indices. SI was also examined in relation to soil type. Multiple samples were available for three types of soil: light clay, medium clay, and till. There were no significant differences between the soil types. © 2011 Taylor & Francis.


Duan L.,Carnegie Institution for Science | Duan L.,National University of Singapore | Dietrich D.,University of Nottingham | Ng C.H.,National University of Singapore | And 5 more authors.
Plant Cell | Year: 2013

The endodermal tissue layer is found in the roots of vascular plants and functions as a semipermeable barrier, regulating the transport of solutes from the soil into the vascular stream. As a gateway for solutes, the endodermis may also serve as an important site for sensing and responding to useful or toxic substances in the environment. Here, we show that high salinity, an environmental stress widely impacting agricultural land, regulates growth of the seedling root system through a signaling network operating primarily in the endodermis. We report that salt stress induces an extended quiescent phase in postemergence lateral roots (LRs) whereby the rate of growth is suppressed for several days before recovery begins. Quiescence is correlated with sustained abscisic acid (ABA) response in LRs and is dependent upon genes necessary for ABA biosynthesis, signaling, and transcriptional regulation. We use a tissue-specific strategy to identify the key cell layers where ABA signaling acts to regulate growth. In the endodermis, misexpression of the ABA insensitive1-1 mutant protein, which dominantly inhibits ABA signaling, leads to a substantial recovery in LR growth under salt stress conditions. Gibberellic acid signaling, which antagonizes the ABA pathway, also acts primarily in the endodermis, and we define the crosstalk between these two hormones. Our results identify the endodermis as a gateway with an ABA-dependent guard, which prevents root growth into saline environments. © 2013 American Society of Plant Biologists. All rights reserved.


Liljenstolpe C.,Swedish University of Agricultural Sciences
Agribusiness | Year: 2011

A choice experiment survey dataset is used to investigate heterogeneous preferences among Swedish consumers for attributes of pig production. To model the preferences, a random parameter logit model and a latent class model are estimated and compared. The comparison, based on predicted probability distribution, regression analysis of the probabilities, and investigation of the probability ratio, suggests that the latent class model is preferred to the random parameter logit model. Estimating a latent class model with three latent classes, using group dependent variables, i.e., class indicators, suggests that preferences may be characterized by food safety and animal welfare dimensions. Calculating the willingness to pay for the variables within each class, the author found that Class 1 is oriented towards animal welfare, Class 3 is oriented towards food safety, and Class 2 is intermediate of Class 1 and Class 3. Moreover, class membership and its implication for the assessment of organic pork are investigated. The respondents within the "food safety-conscious" class have a strong belief that organic food products are safer, though this class is also found to be the most price sensitive. The "animal welfare-conscious" respondents are also price sensitive, but to a lesser extent than the food safety-conscious consumers. Moreover, respondents that show a concern for animal welfare do not believe that organic pork is produced under more animal friendly conditions. The relatively large size of the animal welfare-conscious class and the negative perception of organic pork found in this group suggest that market opportunities exist for the marketing of animal welfare-certified products. [EconLit citations: C010; C500; Q100]. © 2010 Wiley Periodicals, Inc.


Algers B.,Swedish University of Agricultural Sciences
CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources | Year: 2011

Animal welfare science has engaged in the studies of how mainly farm animals, but to a lesser extent also sport and pet animals and laboratory animals, are affected by various environmental factors. With philosophers engaging in animal welfare it became obvious that animal welfare cannot be properly improved without addressing ethical values. A new trend in animal welfare research is to focus on animal-based measures of welfare, making use of positive emotions as measures of good animal welfare and a multidisciplinary approach to the subject of animal welfare. In order to help risk managers to set appropriate priorities, the European Food Safety Authority (EFSA) has taken on the task of developing a risk assessment methodology for animal welfare. In the last decade, the engagement in animal welfare has led to two international bodies working globally to bring on the subject of animal welfare as one of their areas of responsibility. It can be concluded that animal welfare research has developed from merely studies on changes in behaviour and physiological parameters to also include studies of affective states. Research has become more interdisciplinary and often social sciences are part of such research. Animal welfare has become a factor to consider for legislation and international trade. © CAB International 2011.


Bankefors J.,Swedish University of Agricultural Sciences
Journal of mass spectrometry : JMS | Year: 2011

Fifteen identified C-18 fatty acyl-containing saponin structures from Quillaja saponaria Molina have been investigated by electrospray ionization ion-trap multiple-stage mass spectrometry (ESI-IT-MS(n)) in positive ion mode. Their MS(1)-MS(3) spectra were analyzed and ions corresponding to useful fragments, important for the structural identification of Quillaja saponins, were recognized. A few key fragments could describe the structural variations in the C-3 and the C-28 oligosaccharides of the Quillaja saponins. A flowchart involving a stepwise procedure based on key fragments from the MS(1)-MS(3) spectra of these saponins, together with key fragments from these saponins and 13 previously investigated saponins, was constructed for the identification of structural elements in Quillaja saponins. Peak intensity ratios in MS(3) spectra were found to be correlated to structural features of the investigated saponins and is therefore of value for the identification of regioisomers. Copyright © 2011 John Wiley & Sons, Ltd.


Bassel G.W.,University of Birmingham | Bassel G.W.,University of Nottingham | Gaudinier A.,University of California at Davis | Brady S.M.,University of California at Davis | And 3 more authors.
Plant Cell | Year: 2012

Physiological responses, developmental programs, and cellular functions rely on complex networks of interactions at different levels and scales. Systems biology brings together high-throughput biochemical, genetic, and molecular approaches to generate omics data that can be analyzed and used in mathematical and computational models toward uncovering these networks on a global scale. Various approaches, including transcriptomics, proteomics, interactomics, and metabolomics, have been employed to obtain these data on the cellular, tissue, organ, and whole-plant level. We summarize progress on gene regulatory, cofunction, protein interaction, and metabolic networks. We also illustrate the main approaches that have been used to obtain these networks, with specific examples from Arabidopsis thaliana, and describe the pros and cons of each approach. © 2012 American Society of Plant Biologists. All rights reserved.


Johansson J.,Lund University | Bolmgren K.,Lund University | Bolmgren K.,Swedish University of Agricultural Sciences | Jonzen N.,Lund University
Global Change Biology | Year: 2013

Long-term phenology monitoring has documented numerous examples of changing flowering dates during the last century. A pivotal question is whether these phenological responses are adaptive or not under directionally changing climatic conditions. We use a classic dynamic growth model for annual plants, based on optimal control theory, to find the fitness-maximizing flowering time, defined as the switching time from vegetative to reproductive growth. In a typical scenario of global warming, with advanced growing season and increased productivity, optimal flowering time advances less than the start of the growing season. Interestingly, increased temporal spread in production over the season may either advance or delay the optimal flowering time depending on overall productivity or season length. We identify situations where large phenological changes are necessary for flowering time to remain optimal. Such changes also indicate changed selection pressures. In other situations, the model predicts advanced phenology on a calendar scale, but no selection for early flowering in relation to the start of the season. We also show that the optimum is more sensitive to increased productivity when productivity is low than when productivity is high. All our results are derived using a general, graphical method to calculate the optimal flowering time applicable for a large range of shapes of the seasonal production curve. The model can thus explain apparent maladaptation in phenological responses in a multitude of scenarios of climate change. We conclude that taking energy allocation trade-offs and appropriate time scales into account is critical when interpreting phenological patterns. © 2012 Blackwell Publishing Ltd.


Widgren S.,National Veterinary Institute | Frossling J.,Swedish University of Agricultural Sciences
Geospatial Health | Year: 2010

Understanding the intensity and spatial patterns of animal transfers is of prime importance as geographical moves play an important part in the spread and potential control of contagious animal diseases of veterinary importance. For the purpose of visualizing all registered between-herd animal movements in Sweden between 1 July 2005 and 31 December 2008 by map animation, a grid network technique based on the Bresenham line algorithm was developed. Potential spatio-temporal clustering of animals registered as sold or purchased based on location and month of trade was also detected and tested using a spatial scan statistic. Calculations were based on data from 31,375 holdings and 3,487,426 head of cattle. In total, 988,167 between-herd movements of individual bovines were displayed in a sequence of maps covering three and a half years by 2-week intervals. The maps showed that several cattle movements, both short- and long-distance, take place in Sweden each week of the year. However, most animals (75%) were only registered at one single holding during the study period and 23% were sold to a different holding once. Spatial scan statistics based on data from the year 2008 indicated uneven distributions of purchased or sold animals in space and time. During each autumn, there was an increase in cattle movements and October and November showed significantly more cases of sold or purchased animals (relative risk ~1.7, p = 0.001). Based on the results, we conclude that cattle trade is constantly active at a considerable level. This, in combination with possibly insufficient biosecurity routines applied on many farms, constitutes a risk that contagious diseases are spread in the population. The grid network maps were generated through the use of open-source tools and software in order to decrease software costs and facilitate sharing of programme code. In addition, the technique was based on scripts that allow for the inclusion of iterative processes and that comprise all main parts of map creation. Thereby, a large number of maps can be generated and the demands for high reproducibility are met.


Jonsson H.,Swedish University of Agricultural Sciences
FEMS Microbiology Letters | Year: 2013

Segmented filamentous bacteria (SFB) are inhabitants of the small intestine of various animals, where they can be detected microscopically due to their specific morphology and intimate association with the intestinal epithelium. SFB colonize the distal part of the small intestine in a host-specific manner and affects important functions of the immune system, such as the induction of secretory IgA production and regulation of T-cell maturation. Considering the influences SFB have on immune functions, they could be regarded as a key species in host-microbial interactions of the gastrointestinal tract. Although these influences might be executed by other microorganisms, a human-adapted variant of SFB is not unlikely. In this study, ileostomy samples from 10 human subjects were screened with PCR, using primers derived from sequences of SFB from rat and mouse. PCR products were obtained from samples taken from one individual at two time points. Sequencing revealed the presence of a 16S rRNA gene with high similarity (98%) to the corresponding genes from SFB of mouse and rat origin, thus indicating the presence of a human variant of SFB. The findings presented in this study will hopefully encourage research to elucidate whether this intriguing organism is a persistent member of the normal human microbiota. © 2013 Federation of European Microbiological Societies.


Hagman R.,Swedish University of Agricultural Sciences
Reproduction in Domestic Animals | Year: 2012

Contents: Pyometra is a common disease of female dogs. In Sweden, where approximately 90% of the dog population is intact (not neutered), nearly 25% of all female dogs are diagnosed with the disease before 10 years of age. In certain high-risk breeds, this risk of developing pyometra exceeds 50%. Various clinical signs associated with the genital tract as well as with systemic disease are present in dogs with pyometra. A frequent and serious consequence of the uterine infection is endotoxaemia and progression into the systemic inflammatory response syndrome (SIRS), or sepsis, and the disease is then regarded as a medical emergency. Acute phase proteins and inflammatory markers associated with SIRS and with the outcome as measured by length of hospitalization have been identified in blood samples. Recently, the inflammatory response in infected uterine tissue during pyometra has been more closely explored. The expression of many genes associated with chemokines, cytokines, inflammatory cell extravasation, anti-bacterial action, the complement system and innate immune responses and also a large panel of proteases are upregulated in the uterine tissue in pyometra. Products of certain upregulated genes may be detected systemically and used for diagnostic or prognostic purposes provided that tests are developed in the future. More knowledge of the complex local and systemic inflammatory response in pyometra may allow identification of novel disease biomarkers or future targets for treatment. In this article, clinical as well as molecular characteristics of the disease are reviewed. © 2012 Blackwell Verlag GmbH.


Dynesius M.,Umea University | Gibb H.,La Trobe University | Hjalten J.,Swedish University of Agricultural Sciences
PLoS ONE | Year: 2010

Many species use coarse woody debris (CWD) and are disadvantaged by the forestry-induced loss of this resource. A neglected process affecting CWD is the covering of the surfaces of downed logs caused by sinking into the ground (increasing soil contact, mostly covering the underside of the log), and dense overgrowth by ground vegetation. Such cover is likely to profoundly influence the quality and accessibility of CWD for wood-inhabiting organisms, but the factors affecting covering are largely unknown. In a five-year experiment we determined predictors of covering rate of fresh logs in boreal forests and clear-cuts. Logs with branches were little covered because they had low longitudinal ground contact. For branchless logs, longitudinal ground contact was most strongly related to estimated peat depth (positive relation). The strongest predictor for total cover of branchless logs was longitudinal ground contact. To evaluate the effect on cover of factors other than longitudinal ground contact, we separately analyzed data from only those log sections that were in contact with the ground. Four factors were prominent predictors of percentage cover of such log sections: estimated peat depth, canopy shade (both increasing cover), potential solar radiation calculated from slope and slope aspect, and diameter of the log (both reducing cover). Peat increased cover directly through its low resistance, which allowed logs to sink and soil contact to increase. High moisture and low temperatures in pole-ward facing slopes and under a canopy favor peat formation through lowered decomposition and enhanced growth of peat-forming mosses, which also proved to rapidly overgrow logs. We found that in some boreal forests, peat and fast-growing mosses can rapidly cover logs lying on the ground. When actively introducing CWD for conservation purposes, we recommend that such rapid covering is avoided, thereby most likely improving the CWD's longevity as habitat for many species. © 2010 Dynesius et al.


Soler C.C.L.,CNRS Center of Evolutionary and Functional Ecology | Proffit M.,Swedish University of Agricultural Sciences | Bessiere J.-M.,National Graduate School of Chemistry, Montpellier | Hossaert-Mckey M.,CNRS Center of Evolutionary and Functional Ecology | Schatz B.,CNRS Center of Evolutionary and Functional Ecology
Ecology Letters | Year: 2012

The dioecious Mediterranean fig, Ficus carica, displays a unique phenology in which males sometimes bloom synchronously with females (in summer), and sometimes not (in spring). Ficus carica is engaged in an obligatory mutualism with a specific pollinating wasp, which reproduces only within figs, localising them by their specific scents. We show that scents emitted by male figs show seasonal variation within individual trees. Scents of summer male figs resemble those of the co-flowering females, and are different from those of the same male trees in spring, when female figs are absent. These differences hold even if only compounds electrophysiologically active for pollinators are considered. The similar scents of summer males and females may explain why the rewardless females are still pollinated. These results offer a tractable model for future studies of intersexual chemical mimicry in mutualistic pollination interactions. © 2012 Blackwell Publishing Ltd/CNRS.


Zhu F.,University of Hong Kong | Corke H.,University of Hong Kong | Bertoft E.,Swedish University of Agricultural Sciences
Carbohydrate Polymers | Year: 2011

Unit chain length distributions of amylopectins and their φ,β-limit dextrins (reflecting amylopectin internal part) from 11 Chinese sweetpotato genotypes were characterized by high performance anion-exchange chromatography after debranching, and were related to the thermal and pasting properties of granular starches. The weight-based unit chain length profiles of whole amylopectin and their internal parts both had three distinguishable major groups with approximate range of DP 6-36, 37-68, and >69 for amylopectins and DP 3-25, 26-55, and >55 for φ,β-limit dextrins. Among different genotypes, two different patterns of Bfp (fingerprint B-chains, DP 3-7) were observed for φ,β-limit dextrins, whereas Afp (fingerprint A-chains, DP 6-8) for whole amylopectins were consistent. Reconstruction of amylopectins from their φ,β-limit dextrins revealed that B-chains with internal DP > 20 possessed an external chain length corresponding to the average value DP 12.8. Wide genetic variations were recorded among structural parameters, of which several concerning the amylopectin internal part were highly correlated to the thermal and pasting parameters of sweetpotato starches, and suggested that the internal part of amylopectin is critical to the physical behavior of granular starch. © 2010 Elsevier Ltd. All rights reserved.


Josefsson T.,Swedish University of Agricultural Sciences
Holocene | Year: 2014

Archaeological and historical records suggest that cultivation became established rather late in northern Fennoscandia, preferably in coastal villages of northernmost Sweden during the 14th century. The expansion of these settlements has obliterated the relevant biological archives, thus restricting our ability to conduct palaeoecological studies of the oldest villages and limiting our knowledge of their cultivation history. In a secondary phase, new settlements were established around the periphery of these primary villages. We hypothesize that such secondary villages, which generally are only moderately affected by urban expansion, may function as key sites for vegetation-history studies and that the results can be extrapolated to provide clues about the establishment of primary villages and the initiation of associated permanent cultivations. Analyses of pollen, pollen accumulation rates, charred particles and loss-on-ignition residues from a small lake in the secondary village of Arnemark revealed continuous land use from at least c. 1650 cal. BP (cal. ad 300), a step-up phase in grazing and trampling around 1200 cal. BP (cal. ad 750), and permanent cultivation during the last c. 625 years (cal. ad 1325). The results suggest that the secondary village was established around cal. ad 750, that is, c. 600 years earlier than previously thought and that cultivation here was initiated at the same time as has been suggested for the primary villages by the coast. In this study, we also demonstrate that using pollen from old cereal types as references can make the distinction between cereal and wild-grass pollen more reliable. © The Author(s) 2014.


Cong R.-G.,Lund University | Brady M.,Lund University | Brady M.,Swedish University of Agricultural Sciences
PLoS ONE | Year: 2012

In this paper we appraise current agricultural subsidy policy in the EU. Several sources of its inefficiency are identified: it is inefficient for supporting farmers' incomes or guaranteeing food security, and irrational transfer payments decoupled from actual performance that may be negative for environmental protection, social cohesion, etc. Based on a simplified economic model, we prove that there is "reverse redistribution" in the current tax-subsidy system, which cannot be avoided. To find a possible way to distribute subsidies more efficiently and equitably, several alternative subsidy systems (the pure loan, the harvest tax and the income contingent loan) are presented and examined. © 2012 Cong, Brady.


Lindahl G.,Swedish University of Agricultural Sciences
Meat Science | Year: 2011

The aim was to investigate the effects of ageing large beef cuts, 10-cm-long longissimus dorsi (LD) and 4-cm-long semimembranosus (SM), on colour stability during subsequent storage of steaks in air for 5days. Ageing solely in high oxygen modified atmosphere (MA, 80% O 2+20% CO 2) for 5 or 10days or ageing in vacuum for 5 or 15days followed by high oxygen MA for 5 or 10days were compared with ageing in vacuum for 5, 15 and 25days at 4°C. Ageing system and ageing time influenced colour stability. For short ageing times, 5 to 10days, large beef cuts could be aged in high oxygen MA without negative effect on colour stability compared with vacuum ageing. Longer ageing times, 15 to 25days, decreased colour stability. Then vacuum ageing was preferable to ageing in vacuum for 5 or 15days followed by high oxygen MA. © 2010 The American Meat Science Association.


Scogings P.F.,University of Zululand | Hjalten J.,Swedish University of Agricultural Sciences | Skarpe C.,Hedmark University College
Oecologia | Year: 2011

Carbon-based secondary metabolites (CBSMs) are assumed to function as defences that contribute to herbivore-avoidance strategies of woody plants. Severe browsing has been reported to reduce concentrations of CBSMs and increase N concentrations in individual plants, causing heavily browsed plants to be characterised by N-rich/C-poor tissues. We hypothesised that concentrations of condensed tannins (CT) and total polyphenols (TP) should decrease, or N increase, in relation to increasing intensity of browsing, rendering severely browsed plants potentially more palatable (increased N:CT) and less N-limited (increased N:P) than lightly browsed ones. We sampled naturally browsed trees (taller than 2 m) of four abundant species in southern Kruger National Park, South Africa. Species-specific relationships between N:CT, CT, TP and P concentrations and increasing browsing intensity were detected, but N and N:P were consistently invariable. We developed a conceptual post-hoc model to explain diverse species-specific CBSM responses on the basis of relative allocation of C to total C-based defence traits (e.g. spines/thorns, tough/evergreen leaves, phenolic compounds). The model suggests that species with low allocation of C to C-based defence traits become C-limited (potentially more palatable) at higher browsing intensity than species with high allocation of C to C-based defences. The model also suggests that when N availability is high, plants become C-limited at higher browsing intensity than when N availability is low. © 2011 Springer-Verlag.


Chapman W.K.,Borland | Paul L.,Swedish University of Agricultural Sciences
Microbial Ecology | Year: 2012

Tuberculate mycorrhizae on Pinus contorta (lodgepole pine) have previously been shown to reduce acetylene, but an outstanding question has been to what degree these structures could meet the nitrogen requirements of the tree. We compared the growth, tissue nitrogen contents, and stable nitrogen isotope ratios of P. contorta growing in gravel pits to the same species growing on adjacent intact soil. Trees growing in severely nitrogen deficient gravel pits had virtually identical growth rates and tissue nitrogen contents to those growing on intact soil that had nitrogen levels typical for the area. δ15N values for trees in the gravel pits were substantially lower than δ15N values for trees on intact soil, and isotope ratios in vegetation were lower than the isotope ratios of the soil. The form of soil nitrogen in the gravel pits was almost exclusively nitrate, while ammonium predominated in the intact soil. Discrimination against 15N during plant uptake of soil nitrate in the highly N-deficient soil should be weak or nonexistent. Therefore, the low δ15N in the gravel pit trees suggests that trees growing in gravel pits were using another nitrogen source in addition to the soil. Precipitation-borne nitrogen in the study area is extremely low. In conjunction with our other work, these findings strongly suggests that P. contorta and its microbial symbionts or associates fix nitrogen in sufficient amounts to sustain vigorous tree growth on the most nitrogen-deficient soils. © 2012 The Author(s).


Grafstrom A.,Swedish University of Agricultural Sciences | Lundstrom N.L.P.,Umea University | Schelin L.,Umea University
Biometrics | Year: 2012

A simple method to select a spatially balanced sample using equal or unequal inclusion probabilities is presented. For populations with spatial trends in the variables of interest, the estimation can be much improved by selecting samples that are well spread over the population. The method can be used for any number of dimensions and can hence also select spatially balanced samples in a space spanned by several auxiliary variables. Analysis and examples indicate that the suggested method achieves a high degree of spatial balance and is therefore efficient for populations with trends. © 2011, The International Biometric Society.


Berge A.C.,Ghent University | Wierup M.,Swedish University of Agricultural Sciences
Animal | Year: 2012

Nutritional strategies to minimize Salmonella in food animal production are one of the key components in producing safer food. The current European approach is to use a farm-to-fork strategy, where each sector must implement measures to minimize and reduce Salmonella contamination. In the pre-harvest phase, this means that all available tools need to be used such as implementation of biosecurity measures, control of Salmonella infections in animals at the farm as well as in transport and trade, optimal housing and management including cleaning, disinfection procedures as well as efforts to achieve Salmonella-free feed production. This paper describes some nutritional strategies that could be used in farm control programmes in the major mono-gastric food production animals: poultry and pigs. Initially, it is important to prevent the introduction of Salmonella onto the farm through Salmonella-contaminated feed and this risk is reduced through heat treatment and the use of organic acids and their salts and formaldehyde. Microbiological sampling and monitoring for Salmonella in the feed mills is required to minimize the introduction of Salmonella via feed onto the farm. In addition, feed withdrawal may create a stressful situation in animals, resulting in an increase in Salmonella shedding. Physical feed characteristics such as coarse-ground meal to pigs can delay gastric emptying, thereby increasing the acidity of the gut and thus reducing the possible prevalence of Salmonella. Coarse-ground grains and access to litter have also been shown to decrease Salmonella shedding in poultry. The feed can also modify the gastro-intestinal tract microflora and influence the immune system, which can minimize Salmonella colonization and shedding. Feed additives, such as organic acids, short- and medium-chain fatty acids, probiotics, including competitive exclusion cultures, prebiotics and certain specific carbohydrates, such as mannan-based compounds, egg proteins, essential oils and bacteriophages, have the potential to reduce Salmonella levels when added to the feed. These nutritional strategies could be evaluated and used in farm control programmes. © 2011 The Animal Consortium.


Axner E.,Swedish University of Agricultural Sciences
Journal of Feline Medicine and Surgery | Year: 2014

Cats more than 2 months of age have alloantibodies against the blood type antigen that they do not possess. Maternal antibodies, including alloantibodies against blood groups, are transferred to the kittens’ systemic circulation when they suckle colostrum during the first 12–16 h after birth. If kittens with blood group A or AB nurse from a mother with blood group B they may develop neonatal isoerythrolysis (NI). Breeders can prevent kittens at risk of NI from nursing during the first 16–24 h; after this period it is safe to let them nurse. Kittens depend, however, on the passive transfer of antibodies from the colostrum for early protection against infections. Although it is known that kittens deprived of colostrum will also be deprived of passive systemic immunity, it is not known if this will affect their health. Therefore, the aim of this study was to evaluate kitten mortality in litters with B-mothers and A-fathers compared to litters with A-mothers. In addition, the aim was to evaluate the effects of colostrum deprivation on the health of the mothers, and the breeders’ opinions and experiences of these combinations of breedings. A web-based questionnaire was constructed and distributed to breeders. The results indicate that there is no difference in mortality between planned litters that have mothers with blood group A and litters with mothers that have blood group B and fathers that have blood group A. When managing blood group incompatibility in cat all factors affecting the health of the cats, including genetic variation, should be considered. © ISFM and AAFP 2014.


Franzen M.,Helmholtz Center for Environmental Research | Franzen M.,Lund University | Ockinger E.,Swedish University of Agricultural Sciences
Journal of Insect Conservation | Year: 2012

Climate change is occurring more rapidly in the Arctic than elsewhere, and is predicted to have a large impact on biodiversity, since entire cold-adapted ecosystems are likely to disappear. Here, we highlight changes in the insect species richness and community composition of wild bees, butterflies and moths over 60 years in an area situated above the tree limit (Padjelanta National Park) in northern Sweden. Although there were changes in habitat availability, indicated by a significant decrease in the area of a glacier (from 22 km 2 in 1898 to 7.5 km 2 in 2009), and an increase in the area of birch forest in the National Park, we nevertheless found relatively moderate changes in the insect communities. Indeed, the observed number of species increased from 52 in 1944 to 64 in 2008. Remarkably, the mean number of butterflies and moths per site, but not wild bee species, increased significantly. Among the species that were recorded in both periods, the average altitude of 17 species had shifted downhill, 12 shifted uphill, and the altitude of the remaining 17 had not changed. While alterations in community composition were greater at the highest altitudes, changes in the insect community were smaller than expected, indeed much smaller than those reported from agricultural landscapes in North-West Europe. Interestingly, our results suggest that lower alpine altitudes (600-800 m a. s. l.) have become colonized by southern species, but also that high alpine areas (above 1,000 m a. s. l.) have recently become colonized by high alpine species previously absent from these sites, likely as a result of increasing habitat availability. We conclude that wild bee, butterfly, and moth communities in Arctic areas in northern Sweden are in flux, as a result of climate change and suggest that increased attention must be given to conservation planning in cold areas. In addition, we propose that monitoring programs should be established, because more pronounced climate-driven changes can be expected in the future. © 2011 Springer Science+Business Media B.V.


Uden P.,Swedish University of Agricultural Sciences
Journal of Animal Physiology and Animal Nutrition | Year: 2011

A novel macro in vitro system was used to test the theory that rumen proportions of acetate, propionate and butyrate are not representative of their respective net production rates. Whole rumen content (10-16 kg) from two cows was mixed with a bicarbonate buffer and incubated separately in two 40-l in vitro vessels for 3 h. A total of six experimental periods were used. In this study, a total of six cows were used and fed 1/8 of the daily ration by hand every 3 h. To obtain differences in rumen volatile fatty acids (VFA) composition, 1 l of acetate (416 mm), propionate (108 mm), butyrate (79 mm), lactic acid (300 mm) or nothing was infused during 24 h into the rumen before collection of representative samples of rumen contents. Infusions of acids were then continued during the in vitro incubations in exact proportion to the digesta removed from the rumen. In Periods 1 and 2, the cows were alternatively infused with acetate or nothing. In Periods 3 and 4, the infusions consisted of propionate or butyrate and in Periods 5 and 6 of lactate or nothing. Nine liquid samples were obtained between 3 and 180 min after the start of incubation and analysed for concentrations of VFA. Changes in proportions of individual VFA were estimated by linear regression. No differences in VFA proportions were observed in the absence of infusion (p > 0.5) over time, but when individual VFA were infused, their respective proportions increased. This was interpreted as the result of a decreased in vitro fermentation rate of digesta substrates compared with that in the rumen. Lactate infusion increased butyrate proportion in vitro. It is concluded that this study could not provide any evidence that ruminal VFA proportions are unrepresentative of the proportions of net production. © 2010 The Authors. Journal of Animal Physiology and Animal Nutrition © 2010 Blackwell Verlag GmbH.


Bull J.W.,Imperial College London | Suttle K.B.,Imperial College London | Singh N.J.,Swedish University of Agricultural Sciences | Milner-Gulland E.J.,Imperial College London
Frontiers in Ecology and the Environment | Year: 2013

Conservation is particularly difficult to implement for "moving targets", such as migratory species or landscapes subject to environmental change. Traditional conservation strategies involving static tools (eg protected areas that have fixed spatial boundaries) may be ineffective for managing species whose ranges are changing. This shortfall needs to be addressed urgently. More dynamic conservation-based approaches have been suggested but remain mostly theoretical, and so implementation issues and measures of success have yet to be explored. In recent years, however, the concept of biodiversity offsets has gained traction in the conservation community. Such offsets effectively replace biodiversity "lost" during current economic development projects, and are intended to ensure "no net loss" of biodiversity overall. Given their flexibility and unique no-net-loss requirement, offsets provide a platform for testing dynamic new approaches to conservation. Here we explore the potential for offsets to conserve moving targets, using a complex dynamic example: the migratory saiga antelope (Saiga tatarica) in Uzbekistan. © 2013 The Ecological Society of America.


Saarikoski H.,Finnish Environment Institute | Raitio K.,Swedish University of Agricultural Sciences | Barry J.,University of Sheffield
Land Use Policy | Year: 2013

The paper seeks to shed new light on both the dynamics and possibilities for resolving complex land use conflicts by examining the development of the Great Bear Rainforest (GBR) Agreement in British Columbia, Canada. This agreement signalled a major policy change in the region by increasing the protection of old growth forests from 9% to 33% of the total planning area and by promoting more environmentally friendly logging practices though the establishment of ecosystem-based management. It also gave rise to new land use planning relationships between the Province and First Nations. Our analysis shows that 'success' in reaching agreement in land use conflicts can be better understood when political science's work on policy regimes and their background conditions is combined with planning theory's work on deliberative processes. We suggest that collaborative planning theory can complement the policy regime approach by highlighting how process design and the interactions that occur within policy arenas provide the physical and organisational spaces for dialogue, collaboration and policy change. The policy regime approach, on the other hand, helps draws attention to the dynamics of policy processes and consequent changes in governance relations that motivate actors to work together, instead of against each other. © 2012 Elsevier Ltd.


Adom P.K.,Swedish University of Agricultural Sciences | Adom P.K.,University of Professional Studies
Energy Economics | Year: 2015

This study analysed the problem of energy intensity determinants in Nigeria based on the fully modified OLS and canonical cointegration regressions. These methods were preferred since they are able to deal effectively with the second-order bias problems, an often characteristics of time series data. The impacts of price of crude oil, FDI, trade openness and industry structure are asymmetric which suggests the presence of structural effects in parameters. The impact of crude oil price is negative but becomes stronger post-1989 saving .126% more in energy consumption relative to pre-1989. Also, the impacts of FDI and trade openness are negative and significant but become stronger post-1989 saving 11.2% and 0.8% more in energy consumption relative to the baseline, respectively for every one percentage point increase in FDI and trade openness. The impact of industry value-added is positive and significant but weakens after 1989 consuming 1.8% less in energy for every one percentage point increase in industry value-added relative to the baseline. The energy reducing effect of industry value-added post-1989 reflects improvements in the technical characteristics of industrial sector in Nigeria. Last, the result showed that the absorptive capability and industry characteristics of Nigeria are important determinants of how FDI affects energy intensity. This implies that a more integrated FDI programme (considering the country characteristics) rather than a 'one-fit-all' programme is preferable. © 2015 Elsevier B.V.


Jarvis N.J.,Swedish University of Agricultural Sciences
Hydrology and Earth System Sciences | Year: 2011

Many land surface schemes and simulation models of plant growth designed for practical use employ simple empirical sub-models of root water uptake that cannot adequately reflect the critical role water uptake from sparsely rooted deep subsoil plays in meeting atmospheric transpiration demand in water-limited environments, especially in the presence of shallow groundwater. A failure to account for this so-called "compensatory" water uptake may have serious consequences for both local and global modeling of water and energy fluxes, carbon balances and climate. Some purely empirical compensatory root water uptake models have been proposed, but they are of limited use in global modeling exercises since their parameters cannot be related to measurable soil and vegetation properties. A parsimonious physics-based model of uptake compensation has been developed that requires no more parameters than empirical approaches. This model is described and some aspects of its behavior are illustrated with the help of example simulations. These analyses demonstrate that hydraulic lift can be considered as an extreme form of compensation and that the degree of compensation is principally a function of soil capillarity and the ratio of total effective root length to potential transpiration. Thus, uptake compensation increases as root to leaf area ratios increase, since potential transpiration depends on leaf area. Results of "scenario" simulations for two case studies, one at the local scale (riparian vegetation growing above shallow water tables in seasonally dry or arid climates) and one at a global scale (water balances across an aridity gradient in the continental USA), are presented to illustrate biases in model predictions that arise when water uptake compensation is neglected. In the first case, it is shown that only a compensated model can match the strong relationships between water table depth and leaf area and transpiration observed in riparian forest ecosystems, where sparse roots in the capillary fringe contribute a significant proportion of the water uptake during extended dry periods. The results of the second case study suggest that uncompensated models may give biased estimates of long-term evapotranspiration at the continental scale. In the example presented here, the uncompensated model underestimated total evapotranspiration by 5-7% in climates of intermediate aridity, while the ratio of transpiration to evaporation was also smaller than for the compensated model, especially in arid climates. It is concluded that the parsimonious physics-based model concepts described here may be useful in the context of eco-hydrological modeling at local, regional and global scales. © 2011 Author(s).


Walther Y.M.,Swedish University of Agricultural Sciences | Mollmann C.,University of Hamburg
ICES Journal of Marine Science | Year: 2014

An ecosystem approach to management (EAM) aims to secure a healthy ecosystem along with sustainable use of its goods and services. Although the main principles of EAM are agreed upon and desirable, wider implementation of EAM is still a challenge. The difficulties stem from unclear definition and communication of the EAM, lack of routines or protocols to develop ecosystem-based advice, inappropriate institutional structures, and communication issues between scientists, advisers, and managers. Integrated ecosystem assessment (IEA) is an instrument that has proven to help in the implementation of EAM. For successful implementation of EAM and IEA in the European regional seas context, an international forum is required that develops tailor-made EAM tools specific to the different regional ecosystems to overcome fragmented national strategies. We describe a multinational peer network of working groups developed within the International Council for the Exploration of the Sea (ICES) under the auspice of Science Steering Group on Regional Sea Programmes. Available is a wealth of data, expertise, scientific methods, and models for each regional sea. This network can be instrumental in advancing IEA for the implementation of EAM in the North Atlantic seas. © 2014 International Council for the Exploration of the Sea. All rights reserved.


Schlyter F.,Swedish University of Agricultural Sciences
Psyche (New York) | Year: 2012

Reduction of tree mortality caused by bark beetle attacks is not only important for forestry, but also essential for the preservation of biodiversity and forest carbon sinks in the face of climate change. While bark beetle mass trapping (a pull approach) is implemented in practice, few studies exist to estimate its effect. The more complex push-pull tactic has, in contrast, been repeatedly tested during the last decade. I analysed published data from 32 experiments in 9 papers published during 20002011 on Ips typographus and Dendroctonus ponderosae, to test if there was an overall effect of antiattractant semiochemicals, that is, if treatments reduced the number of attacks on standing trees at the habitat or stand scale. This meta-analysis showed a substantial overall effect size (treatment-control means divided by their SD) of -0.96, with some heterogeneity but little evidence of publication bias. There was no effect of beetle species or publication year. Heterogeneity resulted from different designs and beetle population levels (as year of study). The conventional Reduction measure correlated well with effect size (r 2 = 0.7). Recommendations include more precise reporting of responses (avoiding dichotomous data), more unified experimental designs, and further meta-analyses that include grey literature and more beetle species. © 2012 Fredrik Schlyter.


Yahya A.,Swedish University of Agricultural Sciences
Journal of Plant Nutrition | Year: 2010

Net uptake and partitioning of sodium (Na+) and potassium (K+) in plants of two sesame cultivars (Sesamum indicum cv. 'PB-1' and cv. 'UCR') exposed to 20 mM sodium chloride (NaCl) were studied over a period of 28 days. Both cultivars showed a marked discrimination between K+ and Na+ during uptake. The reduction of K+ in the plants caused by the NaCl treatment was of similar magnitude in the two cvs. The cv. 'UCR' showed lower Na+ concentrations in the shoot tissues than 'PB-1' and K+/Na+ selectivity ratios were higher in cv. 'UCR' than in cv. 'PB-1'. At the last sampling on day 28 there was a marked decrease of shoot growth in cv. 'PB-1' in comparison to the cv. 'UCR'. Leaves of cv. 'PB-1' showed clear toxic symptoms, while those of cv. 'UCR' did not. It is concluded that Na+ exclusion from the shoot contributes to salt tolerance of sesame, cv. 'UCR'. © Taylor & Francis Group, LLC.


Zavyalov V.,University of Turku | Zavialov A.,Swedish University of Agricultural Sciences | Zav'Yalova G.,University of Turku | Korpela T.,University of Turku
FEMS Microbiology Reviews | Year: 2010

This review summarizes current knowledge on the structure, function, assembly and biomedical applications of the superfamily of adhesive fimbrial organelles exposed on the surface of Gram-negative pathogens with the classical chaperone/usher machinery. High-resolution three-dimensional (3D) structure studies of the minifibers assembling with the FGL (having a long F1-G1 loop) and FGS (having a short F1-G1 loop) chaperones show that they exploit the same principle of donor-strand complementation for polymerization of subunits. The 3D structure of adhesive subunits bound to host-cell receptors and the final architecture of adhesive fimbrial organelles reveal two functional families of the organelles, respectively, possessing polyadhesive and monoadhesive binding. The FGL and FGS chaperone-assembled polyadhesins are encoded exclusively by the gene clusters of the γ3- and κ-monophyletic groups, respectively, while gene clusters belonging to the γ1-, γ2-, γ4-, and π-fimbrial clades exclusively encode FGS chaperone-assembled monoadhesins. Novel approaches are suggested for a rational design of antimicrobials inhibiting the organelle assembly or inhibiting their binding to host-cell receptors. Vaccines are currently under development based on the recombinant subunits of adhesins. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.


Wallentin C.,Holmen Skog | Nilsson U.,Swedish University of Agricultural Sciences
Forestry | Year: 2014

To assess uncertainties regarding the effects of thinning on risks of storm and snow damage, three thinning treatments (control, normal and heavy: 0, 30 and 61 per cent basal area removal, respectively)with four replicationswere applied in a 33-year-old Norway spruce plantation on a fertile site in south-west Sweden. Amajor storm event occurred three growing seasons after thinning followed by snow damage 2 months later and another storm 2 years later. There was a near-linear relationship between thinning intensity and damage caused by the first storm (adj R2 = 0.94): 7, 42 and 74 per cent of the standing basal area was damaged in the control, normally and heavily thinned plots, respectively. Corresponding percentages after both the storm and snow damage were also approximately linearly correlated with thinning intensity: 8, 53 and 89 per cent, respectively (adj R2 = 0.91). Damage caused by the second storm was related to both previous damage levels and standing basal area in the control and normally thinned plots. Stem taper between breast height and 6 mstemheight was negatively correlated with risk for stormand snow damage in the normally thinned plots. Of the trees categorized as damaged (up-rooted, broken or heavily leaning), the frequency of stembreakage after the first stormwas almost negligible in the normally thinned plots, (,5 per cent),while 24-50 per cent of the damaged stemswere broken (mean, 36 per cent) in the heavily thinned plots. The relative diameter growth of the remaining trees in the control plots, for the first and second growing seasons following the storm and snow damage, were significantly decreased compared with the three preceding years. The results confirm previous findings that increasing thinning intensity increases risks of windfall and highlight the need for new Norway spruce management programmes if climate change results in more frequent storm events. © Institute of Chartered Foresters, 2013.


Mondet F.,University of Otago | Mondet F.,French National Institute for Agricultural Research | Mondet F.,Agro ParisTech | de Miranda J.R.,Swedish University of Agricultural Sciences | And 3 more authors.
PLoS Pathogens | Year: 2014

Over the past fifty years, annual honeybee (Apis mellifera) colony losses have been steadily increasing worldwide. These losses have occurred in parallel with the global spread of the honeybee parasite Varroa destructor. Indeed, Varroa mite infestations are considered to be a key explanatory factor for the widespread increase in annual honeybee colony mortality. The host-parasite relationship between honeybees and Varroa is complicated by the mite's close association with a range of honeybee viral pathogens. The 10-year history of the expanding front of Varroa infestation in New Zealand offered a rare opportunity to assess the dynamic quantitative and qualitative changes in honeybee viral landscapes in response to the arrival, spread and level of Varroa infestation. We studied the impact of de novo infestation of bee colonies by Varroa on the prevalence and titres of seven well-characterised honeybee viruses in both bees and mites, using a large-scale molecular ecology approach. We also examined the effect of the number of years since Varroa arrival on honeybee and mite viral titres. The dynamic shifts in the viral titres of black queen cell virus and Kashmir bee virus mirrored the patterns of change in Varroa infestation rates along the Varroa expansion front. The deformed wing virus (DWV) titres in bees continued to increase with Varroa infestation history, despite dropping infestation rates, which could be linked to increasing DWV titres in the mites. This suggests that the DWV titres in mites, perhaps boosted by virus replication, may be a major factor in maintaining the DWV epidemic after initial establishment. Both positive and negative associations were identified for several pairs of viruses, in response to the arrival of Varroa. These findings provide important new insights into the role of the parasitic mite Varroa destructor in influencing the viral landscape that affects honeybee colonies. © 2014 Mondet et al.


Twelve dairy cows in mid to late lactation were fed iso-nitrogenous diets (161 g CP/kg DM, forage:concentrate ratio 65:35) where rolled barley and coarsely ground seeds from either narrow-leafed lupin or field pea supplemented grass-clover silage. Feed allowance was individually restricted and fixed (18.8 ± 0.6 kg dry matter/day) throughout the experiment to avoid refusals. The experiment was of 2 × 2 change-over design and utilized a previous change-over experiment with 3 periods as covariate. Nitrogen balance was assessed by quantitative urine sampling and fecal spot sampling in eight cows whereas rumen metabolism was studied in four cannulated cows. Production of energy corrected milk was 24.3 kg/day with the lupin diet and 23.2 kg/day with the pea diet (P < 0.05). Daily milk fat yield was also higher (P < 0.05) with the lupin diet. Proportion of feed N excreted in milk did not differ between diets. Milk urea concentration, as well as the amounts of total urinary N and urinary urea were higher (P < 0.05) for the lupin diet, while urinary N proportion of feed N only tended (P = 0.08) to be higher with the lupin diet. N balance was lower with the lupin diet. Digestibilities of organic matter, neutral detergent fiber and crude protein did not differ between diets and neither did ruminal pools of these constituents. In addition, there were no differences between the diets with respect to the ruminal concentrations of NH3-N and total volatile fatty acids, and only minor differences in ruminal pH and ruminal concentrations of iso-acids and α-amino-N. It is concluded that the higher fat content in lupins compared to peas is an advantage in typical Scandinavian home-grown rations and probably explains the higher milk yield in this experiment. Differences in protein utilization between lupins and peas are of small magnitude when fed ground without thermal processing. In practical feeding, ad libitum forage allowance may create response differences between lupin seeds and peas not observed in this experiment. © 2010 Elsevier B.V. All rights reserved.


Ragnarsson S.,Holar University College | Lindberg J.E.,Swedish University of Agricultural Sciences
Livestock Science | Year: 2010

The influence of cutting time of mixed grass haylages on energy and nitrogen (N) metabolism, and the coefficients of total tract apparent digestibility (CTTAD) were studied in four mature Icelandic geldings by performing total collection of faeces and urine. The experiment was arranged as 4 × 4 balanced Latin square. The four haylages used were harvested at different times and were considered to be representative in botanical composition for mixed grass haylages in Iceland. The CTTAD of dry matter (DM), organic matter (OM), crude protein, neutral detergent fibre, acid detergent fibre (ADF) and energy were different (p < 0.05) in the haylage batches. The CTTAD of all dietary components and energy decreased with time of cutting. The content of ADF (% in DM) accounted for a major part of the difference in CTTAD of OM (r2 = 0.95) between haylage batches. The urinary nitrogen losses decreased with date of cutting, while the energy losses in urine (as % of digestible energy intake) were unaffected (p > 0.05). The digestible energy content of the haylages studied ranged from 13.4 to 10.8 MJ/kg DM. © 2010 Elsevier B.V. All rights reserved.


Zetterberg T.,IVL Swedish Environmental Research Institute Ltd | Zetterberg T.,Swedish University of Agricultural Sciences
Science of the Total Environment | Year: 2014

Forest biofuel is a main provider of energy in Sweden and the market is expected to grow even further in the future. Removal of logging residues via harvest can lead to short-term acidification but the long-term effects are largely unknown. The objectives of this study were to 1) model the long-term effect of whole-tree harvest (WTH) on soil and stream water acidity and 2) perform sensitivity analyses by varying the amounts of logging residues, calcium (Ca2+) concentrations in tree biomass and site productivity in nine alternate scenarios. Data from three Swedish forested catchments and the Model of Acidification of Groundwater in Catchments (MAGIC) were used to simulate changes in forest soil exchangeable Ca2+ pools and stream water acid neutralizing capacity (ANC) at Gammtratten, Kindla and Aneboda. Large depletions in soil Ca2+ supply and a reversal of the positive trend in stream ANC were predicted for all three sites after WTH. However, the magnitude of impact on stream ANC varied depending on site and the concentration of mobile strong acid anions. Contrary to common beliefs, the largest decrease in modelled ANC was observed at the well-buffered site Gammtratten. The effects at Kindla and Aneboda were much more limited and not large enough to offset the general recovery from acidification. Varying the tree biomass Ca2+ concentrations exerted the largest impact on modelled outcome. Site productivity was the second most important variable whereas changing biomass amounts left on site only marginally affected the results. The outcome from the sensitivity analyses pointed in the same direction of change as in the base scenario, except for Kindla where soil Ca2+ pools were predicted to be replenished under a given set of input data. The reliability of modelled outcome would increase by using site-specific Ca2+ concentrations in tree biomass and field determined identification of site productivity. © 2014 Elsevier B.V.


Elofsson K.,Swedish University of Agricultural Sciences
Environmental and Resource Economics | Year: 2011

Different nutrient abatement activities jointly determine water quality. Policies are determined by governments at central and local level, implying that decisions can be affected by strategic considerations. In this article, decentralization of wetland policies is analyzed with regard to the environmental and economic consequences. A two-stage game is used to investigate strategic abatement decisions regarding nitrogen fertilizer reductions, waste water treatment plant phosphorus reductions and wetlands, assuming that wetland decision can be decentralized. It is shown that under particular circumstances, strategic consideration may imply that a central government undertakes more abatement than socially optimal, but in most cases the opposite is likely to occur. Decentralization of wetland decisions is advantageous to the central government but only benefits the local government if its wetland technology is considerably more efficient that the central government's. This paper explains why local governments often hesitate to take on additional responsibilities for environmental management, and identifies conditions under which local governments make smaller losses or even gain from delegation. The results also contribute to understanding how strategically optimal matching grants are chosen when governments only take into account their own direct costs of abatement and the central government needs to satisfy the local government's participation constraint. © 2011 The Author(s).


Bengtsson J.,Swedish University of Agricultural Sciences
Ecological Entomology | Year: 2015

1. The concept of ecosystem services (ES) has rapidly entered policy and planning agendas nationally and globally. However, its usefulness is hampered by, for example, insufficient understanding of underlying ecological processes and poorly developed and competing conceptual frameworks. 2. It is suggested that final ecosystem services, such as yield, can be partitioned into components describing contributions from ecosystems (regulating and maintenance ES as natural inputs) and human inputs. This conceptual framework is tested by examining the relative importance of farming system (conventional vs. organic, indicating human inputs, and management), landscape (field shape and landscape heterogeneity), and biological control of aphids by natural enemies (indicating a regulating ES) for barley yield on 10 fields in central Sweden. 3. Although biological control was related to increased yield, its contribution was relatively small (<20%). The farming system explained most of the magnitude and variation in yield (47% of the variation, of which 34% was unique). Landscape and biological control had the largest shared contribution to variation in yield (14%). Conventional farming management seemed to have a larger effect on yield than biological control. This could be interpreted as indicating that agricultural production should be further intensified to increase yields, but a high dependency on external inputs may cause further environmental problems, such as eutrophication, and may not be sustainable. 4. Although preliminary, the results suggest that partitioning of natural and human inputs is useful to analyse the contribution of regulating ES to final ecosystem services, and how ES are co-produced by ecosystems and humans. © 2015 The Royal Entomological Society.


Jonsson S.,Umea University | Skyllberg U.,Swedish University of Agricultural Sciences | Bjorn E.,Umea University
Environmental Science and Technology | Year: 2010

Emission rates of gaseous monomethylmercury (CH3Hg II), as well as elemental mercury (Hg0) and dimethylmercury [(CH3)2HgII], were determined in Hg-contaminated water-sediment microcosms (duplicates of three treatments) by gaseous speciesspecific isotope dilution analysis (SSIDA). Incubation of ∼500 g (wet mass) of sediments containing 30 μ mol of ambient Hg with an addition of 2.6 μ mol of 201HgII tracer resulted in average (n = 6) gaseous emissions of 84 ± 26, 100 ± 37, and 830 ± 380 pmol of ambient CH3HgII, CH3201HgII, and 201Hg0, respectively, during 108 days of incubation. In contrast to Hg0, a transient temporal pattern was observed for measured CH3HgII emission rates, which peaked at day 12 and decreased to much lower levels by theendof the experiments. At day 12,CH3HgII constituted 30-50% of the total emitted gaseous Hg, emphasizing the significance of this species to total Hg emissions from anoxic sediment-water systems. Emission rates of gaseous CH3HgII did not reflect the accumulated CH3HgII content in the sediment, suggesting that emissions mainly originated from newly methylated HgII. Speciation modeling of the pore water suggests that CH3HgII was emitted as CH3HgSH0(g). © 2010 American Chemical Society.


Pacheco-Villalobos D.,University of Lausanne | Sankar M.,University of Lausanne | Ljung K.,Swedish University of Agricultural Sciences | Hardtke C.S.,University of Lausanne
PLoS Genetics | Year: 2013

Observations gained from model organisms are essential, yet it remains unclear to which degree they are applicable to distant relatives. For example, in the dicotyledon Arabidopsis thaliana (Arabidopsis), auxin biosynthesis via indole-3-pyruvic acid (IPA) is essential for root development and requires redundant TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (TAA1) and TAA1-RELATED (TAR) genes. A promoter T-DNA insertion in the monocotyledon Brachypodium distachyon (Brachypodium) TAR2-LIKE gene (BdTAR2L) severely down-regulates expression, suggesting reduced tryptophan aminotransferase activity in this mutant, which thus represents a hypomorphic Bdtar2l allele (Bdtar2lhypo). Counterintuitive however, Bdtar2lhypo mutants display dramatically elongated seminal roots because of enhanced cell elongation. This phenotype is also observed in another, stronger Bdtar2l allele and can be mimicked by treating wild type with L-kynerunine, a specific TAA1/TAR inhibitor. Surprisingly, L-kynerunine-treated as well as Bdtar2l roots display elevated rather than reduced auxin levels. This does not appear to result from compensation by alternative auxin biosynthesis pathways. Rather, expression of YUCCA genes, which are rate-limiting for conversion of IPA to auxin, is increased in Bdtar2l mutants. Consistent with suppression of Bdtar2lhypo root phenotypes upon application of the ethylene precursor 1-aminocyclopropane-1-carboxylic-acid (ACC), BdYUCCA genes are down-regulated upon ACC treatment. Moreover, they are up-regulated in a downstream ethylene-signaling component homolog mutant, Bd ethylene insensitive 2-like 1, which also displays a Bdtar2l root phenotype. In summary, Bdtar2l phenotypes contrast with gradually reduced root growth and auxin levels described for Arabidopsis taa1/tar mutants. This could be explained if in Brachypodium, ethylene inhibits the rate-limiting step of auxin biosynthesis in an IPA-dependent manner to confer auxin levels that are sub-optimal for root cell elongation, as suggested by our observations. Thus, our results reveal a delicate homeostasis of local auxin and ethylene activity to control cell elongation in Brachypodium roots and suggest alternative wiring of auxin-ethylene crosstalk as compared to Arabidopsis. © 2013 Pacheco-Villalobos et al.


Morrison D.A.,Swedish University of Agricultural Sciences
Molecular Biology and Evolution | Year: 2010

Exploratory data analysis (EDA) is a frequently undervalued part of data analysis in biology. It involves evaluating the characteristics of the data "before" proceeding to the definitive analysis in relation to the scientific question at hand. For phylogenetic analyses, a useful tool for EDA is a data-display network. This type of network is designed to display any character (or tree) conflict in a data set, without prior assumptions about the causes of those conflicts. The conflicts might be caused by 1) methodological issues in data collection or analysis, 2) homoplasy, or 3) horizontal gene flow of some sort. Here, I explore 13 published data sets using splits networks, as examples of using data-display networks for EDA. In each case, I performed an original EDA on the data provided, to highlight the aspects of the resulting network that will be important for an interpretation of the phylogeny. In each case, there is at least one important point (possibly missed by the original authors) that might affect the phylogenetic analysis. I conclude that EDA should play a greater role in phylogenetic analyses than it has done. © 2010 The Author. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved.


Rader R.,Lipman | Reilly J.,Lipman | Bartomeus I.,Swedish University of Agricultural Sciences | Winfree R.,Lipman
Global Change Biology | Year: 2013

If climate change affects pollinator-dependent crop production, this will have important implications for global food security because insect pollinators contribute to production for 75% of the leading global food crops. We investigate whether climate warming could result in indirect impacts upon crop pollination services via an overlooked mechanism, namely temperature-induced shifts in the diurnal activity patterns of pollinators. Using a large data set on bee pollination of watermelon crops, we predict how pollination services might change under various climate change scenarios. Our results show that under the most extreme IPCC scenario (A1F1), pollination services by managed honey bees are expected to decline by 14.5%, whereas pollination services provided by most native, wild taxa are predicted to increase, resulting in an estimated aggregate change in pollination services of +4.5% by 2099. We demonstrate the importance of native biodiversity in buffering the impacts of climate change, because crop pollination services would decline more steeply without the native, wild pollinators. More generally, our study provides an important example of how biodiversity can stabilize ecosystem services against environmental change. © 2013 John Wiley & Sons Ltd.


Due to a significant decrease in the cost of DNA sequencing, the number of sequences submitted to the public databases has dramatically increased in recent years. Efficient analysis of these data sets may lead to a significant understanding of the nature of pathogens such as bacteria, viruses, parasites, etc. However, this has raised questions about the efficacy of currently available algorithms for the study of pathogen evolution and construction of phylogenetic trees. While the advanced algorithms and corresponding programs are being developed, it is crucial to optimize the available ones in order to cope with the current need. The protocol presented in this study is optimized using a number of strategies currently being proposed for handling large-scale DNA sequence data sets, and offers a highly efficacious and accurate method for computing phylogenetic trees with limited computer resources. The protocol may take up to 36 h for construction and annotation of a final tree of about 20,000 sequences. © 2013 Landes Bioscience.


Magnusson U.,Swedish University of Agricultural Sciences | Ljungvall K.,Swedish Medical Products Agency
Reproductive Toxicology | Year: 2014

The scientific literature on altered onset of puberty predominantly involves studies on females. This paper reviews current knowledge on the role of environmental pollutants in dysregulation of male puberty in humans, laboratory rodents and farm animals. The methods used to determine the onset of puberty are well developed in humans and farm animals, and standardized across studies in humans. In laboratory rodents standardized external morphological endpoints are used. There is an increasing weight of evidence from epidemiological studies in humans, as well as from experiments in animals, indicating that environmental pollutants dysregulate puberty in males. Most data are from studies on "classical" persistent environmental pollutants. Assessing the effect of multichemical environmental pollution on dysregulation of puberty in humans is more challenging; further solid epidemiological data would likely contribute most to our understanding, especially if combined with systematically collected field-data from selected wildlife. © 2014 The Authors.


Luengo Hendriks C.L.,Swedish University of Agricultural Sciences
IEEE Transactions on Image Processing | Year: 2010

Path openings and closings are morphological operations with flexible line segments as structuring elements. These line segments have the ability to adapt to local image structures, and can be used to detect lines that are not perfectly straight. They also are a convenient and efficient alternative to straight line segments as structuring elements when the exact orientation of lines in the image is not known. These path operations are defined by an adjacency relation, which typically allows for lines that are approximately horizontal, vertical or diagonal. However, because this definition allows zig-zag lines, diagonal paths can be much shorter than the corresponding horizontal or vertical paths. This undoubtedly causes problems when attempting to use path operations for length measurements. This paper 1) Introduces a dimensionality-independent implementation of the path opening and closing algorithm by Appleton and Talbot, 2) Proposes a constraint on the path operations to improve their ability to perform length measurements, and 3) Shows how to use path openings and closings in a granulometry to obtain the length distribution of elongated structures directly from a gray-value image, without a need for binarizing the image and identifying individual objects. © 2010 IEEE.


Rocklinsberg H.,Swedish University of Agricultural Sciences
Journal of Agricultural and Environmental Ethics | Year: 2015

Future global food insecurity due to growing population as well as changing consumption demands and population growth is sometimes suggested to be met by increase in aquaculture production. This raises a range of ethical issues, seldom discussed together: fish welfare, food security, human health, climate change and environment, and public concern and legislation, which could preferably be seen as pieces in a puzzle, accepting their interdependency. A balanced decision in favour of or against aquaculture needs to take at least these issues into consideration. It is further argued that in the parallel discussion on increased livestock production animal welfare is an inevitable element both in relation to current legislation in many countries but also in relation to our perception of moral, whereas awareness of fish welfare is low. Both EU legislation and labelling concerning fish is mainly limited to environmental aspects. It is argued that EU shows a split perception of fish, on the one hand acknowledging scientific evidence of fish capacities but on the other excludes fish from detailed legislation. Combining the claim of the Treaty of Lisbon to pay full regard to animal welfare and scientific evidence fish are sentient it is concluded that fish welfare need to be considered in any farming practice and any ethical consideration of increased aquaculture. This might be facilitated taking a basis in our own vulnerability and interdependence, combined with moral responsibility to show sentient beings a ‘loving kindness’—an extension of Cora Diamond’s argument regarding mammals. © 2014, Springer Science+Business Media Dordrecht.


Josefsson S.,Umea University | Leonardsson K.,Swedish University of Agricultural Sciences | Gunnarsson J.S.,University of Stockholm | Wiberg K.,Umea University
Environmental Science and Technology | Year: 2010

Bioturbation can remobilize previously buried contaminants, leading to an increased exposure of aquatic biota. The remobilization of buried polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) from three different sediment depth layers (2.0-2.5 cm, 5.0-5.5 cm, and 10.0-10.5 cm) was studied in a laboratory experiment with two benthic macrofauna species, the amphipod Monoporeia affinis and the polychaete Marenzelleria spp. Remobilization of PCBs and PBDEs was significantly higher in the presence of Marenzelleria spp. than in M. affinis treatments and controls (without macrofauna). The highest remobilization occurred from the most shallow layers (2.0-2.5 cm > 5.0-5.5 cm > 10.0-10.5 cm), but contaminants were remobilized due to bioturbation from layers down to at least 10 cm. Congeners with lower hydrophobicity were remobilized to a higher extent than more hydrophobic congeners. The contaminant distribution between the particulate and the dissolved phase in the water column depended on hydrophobicity and burial depth of the contaminant, with congeners from deeper layers displaying an increased distribution to the particulate phase. Release fluxes and sediment-to-water mass transfer coefficients (MTCs) show that bioturbation by the polychaete Marenzelleria spp. can lead to a significant remobilization of buried contaminants from Baltic Sea sediments. © 2010 American Chemical Society.


Hoglund S.,Swedish University of Agricultural Sciences
Ecological Entomology | Year: 2014

Characteristics that determine a plant's quality as herbivore food exhibit within-plant heterogeneity. Most models suggest negative effects from secondary chemicals. Less work has focused on plant growth dynamics that might also be important in creating heterogeneity in the distribution of food resources among leaves within the plant. Gall-forming insects are sessile during their feeding stage and are therefore of particular interest when assessing the relative importance of growth and non-growth processes in plants. Galls act as sinks for photoassimilates, and successful redirection of these resources requires that gall formation takes place in plant modules that are in an active growth phase. The gall midge Dasineura marginemtorquens infests leaves of the fast-growing Salix viminalis. Several young leaves per shoot are used as oviposition sites during any single egg-laying occasion. This study investigates the extent to which growth in leaves that are apparently suitable for gall initiation varies along shoots of S. viminalis, and tests whether or not such variation affects the fitness and performance of D. marginemtorquens. The relative position of the galled leaves along a shoot was found to determine the success of the gall midge in terms of larval survival, larval developmental time, and adult size. Leaf growth dynamics, but not leaf size, was associated with the variation in insect fitness and performance. Thus, when considering habitat quality for a sessile insect like D. marginemtorquens, the length of time that the galling site acts as a photoassimilate sink is more important than the final size of the plant module. © 2013 The Royal Entomological Society.


Mayor J.R.,Smithsonian Tropical Research Institute | Mayor J.R.,Swedish University of Agricultural Sciences | Wright S.J.,Smithsonian Tropical Research Institute | Turner B.L.,Smithsonian Tropical Research Institute
Journal of Ecology | Year: 2014

The concentration, stoichiometry and resorption of nitrogen (N) and phosphorus (P) in plant leaves are often used as proxies of the availability of these growth-limiting nutrients, but the responses of these metrics to changes in nutrient availability remain largely untested for tropical forest trees. We evaluated changes in N and P concentrations, N/P ratios and resorption for four common tree species after 13 years of factorial N and P additions in a lowland tropical forest in Panama. Chronic P addition increased foliar P concentrations, decreased P resorption proficiency and decreased N/P ratios in three locally common eudicot tree species (Alseis blackiana, Heisteria concinna, Tetragastris panamensis). The increase in foliar P involved similar proportional increases in organic and inorganic P in two species and a disproportionately large increase in inorganic P in A. blackiana. Nitrogen addition did not alter foliar N concentrations in any species, but did decrease N resorption proficiency in H. concinna. A fourth species, the palm Oenocarpus mapora, demonstrated remarkably static foliar nutrient concentrations, responding only with a marginal decrease in P resorption proficiency under N plus P co-addition. Synthesis. Collectively, these results suggest that adjustment of N/P ratios can be expected in eudicots exposed to elevated P, but foliar N appears to already be at optimal levels in these lowland rain forest tree species. The complexity of species-specific responses to altered nutrient availability highlights the difficulty in predicting future responses of tropical forest trees to a changing world. Collectively, these results suggest that adjustment of N/P ratios can be expected in eudicots exposed to elevated P, but foliar N appears to already be at optimal levels in these lowland rain forest tree species. The complexity of species-specific responses to altered nutrient availability highlights the difficulty in predicting future responses of tropical forest trees to a changing world. © 2013 British Ecological Society.


Andersson L.,Uppsala University | Andersson L.,Swedish University of Agricultural Sciences
Current Opinion in Genetics and Development | Year: 2013

The phenotypic diversity in domestic animals provides a unique opportunity to study genotype-phenotype relationships. The identification of causal mutations provides an insight into what types of mutations have contributed to phenotypic evolution in domestic animals. Whole genome sequencing has revealed that fixation of null alleles that inactivate genes, which are essential under natural conditions but disadvantageous on the farm, has not been a common mechanism for genetic adaptation in domestic animals. Numerous examples have been revealed where structural changes cause specific phenotypic effects by altering transcriptional regulation. An emerging feature is also the evolution of alleles by the accumulation of several consecutive mutations which affect gene function. © 2013 Elsevier Ltd.


Johansson V.,University of Stockholm | Lonnell N.,University of Stockholm | Sundberg S.,Swedish University of Agricultural Sciences | Hylander K.,University of Stockholm
Journal of Ecology | Year: 2014

Adequately describing the dispersal mechanisms of a species is important for understanding and predicting its distribution dynamics in space and time. For wind-dispersed species, the transportation of airborne propagules is comparatively well studied, while the mechanisms triggering propagule release are poorly understood, especially for cryptogams. We investigated the effect of wind speed and turbulence on spore release in the moss Atrichum undulatum in a wind tunnel. Specifically, we measured the amount of spores released from sporophytes when exposed to different wind speeds, in high and low turbulence, using a particle counter. We also related spore release to variation in vibrations of the sporophyte and investigated how the vibrations were affected by wind speed, turbulence and sporophyte length (here including capsule, seta and the top part of the shoot). We show that in high turbulence, the amount of spores released increased with increasing wind speed, while in low turbulence, it did not, within the wind speed range 0.8-4.3 m s-1. However, there was a threshold in wind speed (̃2.5-3 m s-1) before large amounts of spores started to be released in turbulent flow, which coincided with incipient vibrations of the sporophyte. Thresholds in wind variation, rather than average wind speed, seemed to initiate sporophyte vibrations. The vibration threshold increased with decreasing sporophyte length. The deposition of spores near the source decreased with increasing wind variation during the time of their release, based on simulated spore deposition from another study of moss dispersal. Synthesis. We suggest that vibration of moss sporophytes is an important mechanism to regulate spore release and that turbulence and sporophyte length regulate the onset of sporophyte vibration. Spore release thresholds affect dispersal distances and have implications for our understanding and predictions of species distribution patterns, population dynamics and persistence. The mechanisms of this phase of the dispersal process are also important to explore for other species, as there may be a substantial variation depending on the species' different traits. © 2014 British Ecological Society.


Berglund B.,Agricultural University of Iceland | Hallgren L.,Swedish University of Agricultural Sciences | Aradottir A.L.,Agricultural University of Iceland
Ecology and Society | Year: 2013

Stakeholder participation in environmental management is increasing. Staff of environmental agencies, however, often lack training in communication and in conducting participatory processes. Their interpretation of "participation" is of interest because interpretation affects how participation is practiced. We explored how participation was interpreted within the Soil Conservation Service of Iceland and how the interpretation affected how participation was carried out in two land restoration projects. Our methods included semi-structured interviews with agency staff and involved stakeholders, participant observations, and document review. The findings showed that participation was seen as a method to accomplish the agency's tasks, and the focus was primarily on the outputs, or products, of the participatory processes. This interpretation worked well and created positive outcomes as long as process factors, such as interaction with other stakeholders and shared influence, were adequately attended to and joint gains were assured, but other stakeholders expressed dissatisfaction when they were not. We conclude that, although tangible outcomes are necessary for environmental agencies, maintaining a balance between product and process focus in participatory projects is important for optimal results. To increase their ability to deal with process factors, environmental agencies, and ultimately environmental management, would benefit from enhancing their personnel's understanding of participation, and capacity to conduct participatory processes. To facilitate participation, this understanding should also be integrated in the institutional framework the agencies work within. © 2013 by the author(s).


Cromsigt J.P.G.M.,Swedish University of Agricultural Sciences | Cromsigt J.P.G.M.,Nelson Mandela Metropolitan University | Cromsigt J.P.G.M.,University of Oslo | te Beest M.,Umea University
Journal of Ecology | Year: 2014

Megaherbivores have been lost from most ecosystems world-wide, and current increases in poaching of rhino and elephant spp. threaten their status in the systems where they still occur. Although megaherbivores are said to be key drivers of ecosystem structure and functioning, empirical evidence is strongly biased to studies on African elephant. We urgently need a better understanding of the impact of other megaherbivore species to predict the consequences of megaherbivore loss. We used a unique 'recolonization experiment' to test how a megagrazer, white rhinoceros, is affecting the structure of savanna grasslands in Kruger National Park (KNP). With a 30-year record of rhinoceros distribution, we quantified how they recolonized KNP following their re-introduction. This allowed us to identify landscapes with high rhino densities and long time since recolonization versus landscapes with low rhino densities that were recolonized more recently but were otherwise biophysically similar. We recorded grassland heterogeneity on 40 transects covering a total of 30 km distributed across both landscapes. We used two proxies of grassland heterogeneity: % short grass cover and number of grazing lawn patches. Grazing lawns are patches with specific communities of prostrate-growing stoloniferous short grass species. Short grass cover was clearly higher in the high rhino impact (17.5%) than low rhino impact landscape (10.7%). Moreover, we encountered ~20 times more grazing lawns in the high rhino impact landscape. The effect of rhino on number of lawns and on short grass cover was similar to the two dominant geologies in KNP, basalt-derived versus granite-derived soils. Synthesis. We provide empirical evidence that white rhinoceros may have started to change the structure and composition of KNP's savanna grasslands. It remains to be tested if these changes lead to other ecological cascading effects. However, our results highlight that the current rhino poaching crisis may not only affect the species, but also threaten the potential key role of this megaherbivore as a driver of savanna functioning. We provide empirical evidence that white rhinoceros may have started to change the structure and composition of Kruger National Park's savanna grasslands. It remains to be tested if these changes lead to other ecological cascading effects. Our results highlight that the current rhino poaching crisis may not only affect the species, but also threaten the potential key role of this megaherbivore as a driver of savanna functioning. © 2014 British Ecological Society.


Hytteborn H.,Uppsala University | Hytteborn H.,Norwegian University of Science and Technology | Verwijst T.,Swedish University of Agricultural Sciences
Journal of Vegetation Science | Year: 2014

Questions: Can assumptions of the existence of spatially distinct patches (delineated structurally homogeneous parts of the forest, being either areas consisting of canopy trees or areas without canopy trees but in an early or later regenerative phase) and of directional development over time of the vegetation in such patches, as implied by current theory of storm gap dynamics, be verified by remapping previous study sites? Location: Natural, unmanaged boreo-nemoral spruce-dominated forest in eastern central Sweden. Methods: By re-mapping three plots, ca, 50 yr after the first inventory, we studied the structure and dynamics of gaps (patches without canopy tree cover) and major tree populations. The old and new maps allowed us to compare two independent assessments of the forest dynamics: one based on tree population changes and one on changes in gap area over time. Results: The current population structure could partly be described through the earlier-encountered structures of the different tree populations and consecutive processes of recruitment and mortality. However, the re-mapping exercise showed that spatially delineated patches did not develop directionally over time, nor was their development spatially discrete. Conclusions: Patch dynamics proceeds in such a way that the fate of a single patch may depend on the development of neighbouring patches. As gaps may partly close or merge into larger gaps, and as gap disappearance rate is a function of actual gap size, performance of an initially delimited patch is largely determined by developments in neighbouring patches and cannot be predicted from its momentary patch characteristics. Consequently, we propose an 'open matrix model' to describe the changes in a boreo-nemoral spruce forest, rather than a 'storm gap dynamics' model. © 2013 International Association for Vegetation Science.


Ezebilo E.E.,Swedish University of Agricultural Sciences
International Journal of Environmental Research | Year: 2010

This paper discusses the study of community's preferences for biodiversity conservation management institution which may motivate them to support conservation efforts in the Okwangwo Division of the Cross River National Park, Nigeria. The empirical data was generated from personal interviews and factors influencing the respondents' choice were examined with the aid of multinomial logit model. The results showed that most of the respondents preferred an institution that has less transaction costs. Respondents' choice of biodiversity conservation institution were influenced by factors such as income from farming activities, income from non-timber forest products, and income from non-traditional employment. This study will contribute to the knowledge of natural resource management policy.


Manzoni S.,Duke University | Taylor P.,University of Colorado at Boulder | Richter A.,University of Vienna | Porporato A.,Duke University | Agren G.I.,Swedish University of Agricultural Sciences
New Phytologist | Year: 2012

Carbon (C) metabolism is at the core of ecosystem function. Decomposers play a critical role in this metabolism as they drive soil C cycle by mineralizing organic matter to CO2. Their growth depends on the carbon-use efficiency (CUE), defined as the ratio of growth over C uptake. By definition, high CUE promotes growth and possibly C stabilization in soils, while low CUE favors respiration. Despite the importance of this variable, flexibility in CUE for terrestrial decomposers is still poorly characterized and is not represented in most biogeochemical models. Here, we synthesize the theoretical and empirical basis of changes in CUE across aquatic and terrestrial ecosystems, highlighting common patterns and hypothesizing changes in CUE under future climates. Both theoretical considerations and empirical evidence from aquatic organisms indicate that CUE decreases as temperature increases and nutrient availability decreases. More limited evidence shows a similar sensitivity of CUE to temperature and nutrient availability in terrestrial decomposers. Increasing CUE with improved nutrient availability might explain observed declines in respiration from fertilized stands, while decreased CUE with increasing temperature and plant C:N ratios might decrease soil C storage. Current biogeochemical models could be improved by accounting for these CUE responses along environmental and stoichiometric gradients. © 2012 The Authors New Phytologist © 2012 New Phytologist Trust.


Hobbie E.A.,University of New Hampshire | Hogberg P.,Swedish University of Agricultural Sciences
New Phytologist | Year: 2012

Contents: Summary 367 I. Introduction 367 II. Background on isotopes 368 III. Patterns of soil δ15N 370 IV. Patterns of fungal δ15N 372 V. Biochemical basis for the influence of fungi on δ15N patterns in plant-soil systems 373 VI. Patterns of δ15N in plant and fungal culture studies 374 VII. Mycoheterotrophic and parasitic plants 375 VIII. Patterns of foliar δ15N in autotrophic plants 376 IX. Controls over plant δ15N 377 X. Conclusions and research needs 378 Acknowledgements 379 References 379 Summary: In this review, we synthesize field and culture studies of the 15N/14N (expressed as δ15N) of autotrophic plants, mycoheterotrophic plants, parasitic plants, soil, and mycorrhizal fungi to assess the major controls of isotopic patterns. One major control for plants and fungi is the partitioning of nitrogen (N) into either 15N-depleted chitin, ammonia, or transfer compounds or 15N-enriched proteinaceous N. For example, parasitic plants and autotrophic hosts are similar in δ15N (with no partitioning between chitin and protein), mycoheterotrophic plants are higher in δ15N than their fungal hosts, presumably with preferential assimilation of fungal protein, and autotrophic, mycorrhizal plants are lower in 15N than their fungal symbionts, with saprotrophic fungi intermediate, because mycorrhizal fungi transfer 15N-depleted ammonia or amino acids to plants. Similarly, nodules of N2-fixing bacteria transferring ammonia are often higher in δ15N than their plant hosts. N losses via denitrification greatly influence bulk soil δ15N, whereas δ15N patterns within soil profiles are influenced both by vertical patterns of N losses and by N transfers within the soil-plant system. Climate correlates poorly with soil δ15N; climate may primarily influence δ15N patterns in soils and plants by determining the primary loss mechanisms and which types of mycorrhizal fungi and associated vegetation dominate across climatic gradients. © 2012 New Phytologist Trust.


Sjostedt C.S.,KTH Royal Institute of Technology | Gustafsson J.P.,KTH Royal Institute of Technology | Kohler S.J.,Swedish University of Agricultural Sciences
Environmental Science and Technology | Year: 2010

A consistent chemical equilibrium model that calculates pH from charge balance constraints and aluminum and iron speciation in the presence of natural organic matter is presented. The model requires input data for total aluminum, iron, organic carbon, fluoride, sulfate, and charge balance ANC. The model is calibrated to pH measurements (n = 322) by adjusting the fraction of active organic matter only, which results in an error of pH prediction on average below 0.2 pH units. The small systematic discrepancy between the analytical results for the monomeric aluminum fractionation and the model results is corrected for separately for two different fractionation techniques (n = 499) and validated on a large number (n = 3419) of geographically widely spread samples all over Sweden. The resulting average error for inorganic monomeric aluminum is around 1 μM. In its present form the model is the first internally consistent modeling approach for Sweden and may now be used as a tool for environmental quality management. Soil gibbsite with a log*K s of 8.29 at 25 °C together with a pH dependent loading function that uses molar Al/C ratios describes the amount of aluminum in solution in the presence of organic matter if the pH is roughly above 6.0. © 2010 American Chemical Society.


Brownfield L.,ETH Zurich | Kohler C.,ETH Zurich | Kohler C.,Swedish University of Agricultural Sciences
Journal of Experimental Botany | Year: 2011

Polyploids, organisms with more than two sets of chromosomes, are widespread in flowering plants, including many important crop species. Increases in ploidy level are believed to arise commonly through the production of gametes that have not had their ploidy level reduced during meiosis. Although there have been cytological descriptions of unreduced gamete formation in a number of plants, until recently none of the underlying genes or molecular mechanisms involved in unreduced gamete production have been described. The recent discovery of several genes in which mutations give rise to a high frequency of unreduced gametes in the model plant Arabidopsis thaliana opens the door to the elucidation of this important event and its manipulation in crop species. Here this recent progress is reviewed and the identified genes and the mechanism by which the loss of protein function leads to the formation of unreduced gametes are discussed. The potential to use the knowledge gained from Arabidopsis mutants to design tools and develop techniques to engineer unreduced gamete production in important crop species for use in plant breeding is also discussed. © 2010 The Author.


Esbensen K.H.,University of Aalborg | Geladi P.,Swedish University of Agricultural Sciences
Journal of Chemometrics | Year: 2010

Validation in chemometrics is presented using the exemplar context of multivariate calibration/prediction. A phenomenological analysis of common validation practices in data analysis and chemometrics leads to formulation of a set of generic Principles of Proper Validation (PPV), which is based on a set of characterizing distinctions: (i) Validation cannot be understood by focusing on the methods of validation only; validation must be based on full knowledge of the underlying definitions, objectives, methods, effects and consequences-which are all outlined and discussed here. (ii) Analysis of proper validation objectives implies that there is one valid paradigm only: test set validation. (iii) Contrary to much contemporary chemometric practices (and validation myths), cross-validation is shown to be unjustified in the form of monolithic application of a one-for-all procedure (segmented cross-validation) on all data sets. Within its own design and scope, cross-validation is in reality a sub-optimal simulation of test set validation, crippled by a critical sampling variance omission, as it manifestly is based on one data set only (training data set). Other re-sampling validation methods are shown to suffer from the same deficiencies. The PPVare universal and can be applied to all situations in which the assessment of performance is desired: prediction-, classification-, time series forecasting-, modeling validation. The key element of PPV is the Theory of Sampling (TOS), which allow insight into all variance generating factors, especially the so-called incorrect sampling errors, which, if not properly eliminated, are responsible for a fatal inconstant sampling bias, for which no statistical correction is possible. In the light of TOS it is shown how a second data set (test set, validation set) is critically necessary for the inclusion of the sampling errors incurred in all 'future'situations in which the validated model must perform. Logically, therefore, all one data set re-sampling approaches for validation, especially cross-validation and leverage-corrected validation, should be terminated, or at the very least used only with full scientific understanding and disclosure of their detrimental variance omissions and consequences. Regarding PLS-regression, an emphatic call is made for stringent commitment to test set validation based on graphical inspection of pertinent t-u plots for optimal understanding of the X-Y interrelationships and for validation guidance. QSAR/QSAP forms a partial exemption from the present test set imperative with no generalization potential. © 2010 John Wiley & Sons, Ltd.


Nicolia A.,University of Perugia | Nicolia A.,Swedish University of Agricultural Sciences | Manzo A.,Ministry of Agriculture | Veronesi F.,University of Perugia | Rosellini D.,University of Perugia
Critical Reviews in Biotechnology | Year: 2014

The technology to produce genetically engineered (GE) plants is celebrating its 30th anniversary and one of the major achievements has been the development of GE crops. The safety of GE crops is crucial for their adoption and has been the object of intense research work often ignored in the public debate. We have reviewed the scientific literature on GE crop safety during the last 10 years, built a classified and manageable list of scientific papers, and analyzed the distribution and composition of the published literature. We selected original research papers, reviews, relevant opinions and reports addressing all the major issues that emerged in the debate on GE crops, trying to catch the scientific consensus that has matured since GE plants became widely cultivated worldwide. The scientific research conducted so far has not detected any significant hazards directly connected with the use of GE crops; however, the debate is still intense. An improvement in the efficacy of scientific communication could have a significant impact on the future of agricultural GE. Our collection of scientific records is available to researchers, communicators and teachers at all levels to help create an informed, balanced public perception on the important issue of GE use in agriculture. © 2014 Informa Healthcare USA, Inc. All rights reserved: reproduction in whole or part not permitted.


Ahlgren S.,Swedish University of Agricultural Sciences | Di Lucia L.,Lund University
Biotechnology for Biofuels | Year: 2014

The issue of indirect land use changes (ILUC) caused by the promotion of transport biofuels has attracted considerable attention in recent years. In this paper, we reviewed the current literature on modelling work to estimate emissions of greenhouse gases (GHG) caused by ILUC of biofuels. We also reviewed the development of ILUC policies in the EU. Our review of past modelling work revealed that most studies employ economic equilibrium modelling and focus on ethanol fuels, especially with maize as feedstock. It also revealed major variation in the results from the models, especially for biodiesel fuels. However, there has been some convergence of results over time, particularly for ethanol from maize, wheat and sugar cane. Our review of EU policy developments showed that the introduction of fuel-specific ILUC factors has been officially suggested by policymakers to deal with the ILUC of biofuels. The values proposed as ILUC factors in the policymaking process in the case of ethanol fuels are generally in line with the results of the latest modelling exercises, in particular for first-generation ethanol fuels from maize and sugar cane, while those for biodiesel fuels are somewhat higher. If the proposed values were introduced into EU policy, no (first-generation) biodiesel fuel would be able to comply with the EU GHG saving requirements. We identified a conflict between the demand from EU policymakers for exact, highly specific values and the capacity of the current models to supply results with that level of precision. We concluded that alternative policy approaches to ILUC factors should be further explored. © 2014 Ahlgren and Di Lucia; licensee BioMed Central Ltd.


Allen C.R.,U.S. Geological Survey | Angeler D.G.,Swedish University of Agricultural Sciences | Garmestani A.S.,U.S. Environmental Protection Agency | Gunderson L.H.,Emory University | Holling C.S.,Resilience
Ecosystems | Year: 2014

The concept of panarchy provides a framework that characterizes complex systems of people and nature as dynamically organized and structured within and across scales of space and time. It has been more than a decade since the introduction of panarchy. Over this period, its invocation in peer-reviewed literature has been steadily increasing, but its use remains primarily descriptive and abstract. Here, we discuss the use of the concept in the literature to date, highlight where the concept may be useful, and discuss limitations to the broader applicability of panarchy theory for research in the ecological and social sciences. Finally, we forward a set of testable hypotheses to evaluate key propositions that follow from panarchy theory. © 2014 Springer Science+Business Media New York (outside the USA).


Flysjo A.,Arla Foods | Flysjo A.,University of Aarhus | Cederberg C.,Swedish Institute for Food and Biotechnology | Henriksson M.,Swedish University of Agricultural Sciences | Ledgard S.,Agresearch Ltd.
Journal of Cleaner Production | Year: 2012

Two most critical factors to address in environmental system analysis of future milk production are 1) the link between milk and beef production, and 2) the competition for land, possibly leading to land use change (LUC) with greenhouse gas (GHG) emissions and loss of biodiversity as important implications. Different methodological approaches concerning these factors, in studies on environmental impacts of dairy production, sometimes lead to contradictory results. Increasing milk yield per cow is often one of the solutions discussed in order to reduce GHG emissions from milk production. However, when also accounting for other systems affected (e.g. beef production) it is not certain that an increase in milk yield per cow leads to a reduction in total GHG emissions per kg milk. In the present study the correlation between carbon footprint (CF) of milk and the amount of milk delivered per cow is investigated for 23 dairy farms (both organic and conventional) in Sweden. Use of a fixed allocation factor of 90% (based on economic value) indicates a reduction in CF with increased milk yield, while no correlation can be noted when system expansion is applied. The average CF for two groups of farms, organic and high yielding conventional, is also calculated. When conducting system expansion the CF is somewhat lower for the organic farms (which have a lower milk yield per cow, but more meat per kg milk), but when a 90% allocation factor is used, the CF is somewhat higher for the organic farms compared to the high yielding conventional farms. In analysis of future strategies for milk production, it is suggested that system expansion should be applied, in order to also account for environmental impacts from affected systems. Thus, scenarios for milk and meat production should be analysed in an integrated approach in order to reduce total emissions from the livestock sector. How to account for emissions from LUC is highly debated and there is no current shared consensus. Different LUC methods result in significantly different results. In this study, four different LUC methods are applied, using data for organic milk production and high yielding conventional milk production systems in Sweden. Depending on which LUC method was applied, the organic system showed about 50% higher or 40% lower CF compared to the conventional high yielding system. Thus, when reporting CF numbers, it is important to report LUC-factors separately and clearly explain the underlying assumptions, since the method of accounting for LUC can drastically change the results. © 2011 Elsevier Ltd. All rights reserved.


Karlsson J.,Swedish University of Agricultural Sciences | Sjostrom M.,Umea University
Ecology and Society | Year: 2011

Studies of how proactive measures to reduce livestock depredation by carnivores affect human tolerance toward carnivores are extremely rare. Nevertheless, substantial amounts of money are spent each year on proactive measures to facilitate large carnivore conservation. The objective of this study was to assess how subsidies for proactive measures to reduce sheep losses to wolves are associated with public attitudes toward wolves. The respondents were 445 people living inside wolf territories in Sweden. Our data set is unique because we combine wolf territory level information regarding proactive subsidies and wolf attacks on dogs and sheep with geographical information of the respondents. Consequently, the respondents can be assigned to a specific wolf territory. The number of wolf attacks on sheep and dogs in the respective territories as well as the number of years that the wolf territory had existed did not affect human attitudes toward wolves. Subsidies for proactive measures to reduce wolf predation on sheep significantly increased positive attitudes toward wolf presence on the local scale. The magnitude of the effect of subsidies for proactive measures was comparable to the effect of other variables well known to affect human attitudes toward wolves such as age or education. Our data show that subsidies not only made the already positive more positive, but also made people with negative attitudes to wolf presence locally, less negative. Our conclusion is, therefore, that subsidies for proactive measures are an effective tool when working with "the human dimension" of conservation biology. © 2011 by the author(s).


Naddafi R.,Swedish University of Agricultural Sciences | Rudstam L.G.,Cornell University
PLoS ONE | Year: 2013

Cascading trophic interactions are often defined as the indirect effects of a predator on primary producers through the effect of the predator on herbivores. These effects can be both direct through removal of herbivores [density-mediated indirect interactions (DMIIs)] or indirect through changes in the behavior of the herbivores [trait-mediated indirect interactions (TMIIs)]. How the relative importance of these two indirect interactions varies with predator diversity remains poorly understood. We tested the effect of predator diversity on both TMIIs and DMIIs on phytoplankton using two competitive invasive dreissenid mussel species (zebra mussel and quagga mussel) as the herbivores and combinations of one, two or all three species of the predators pumpkinseed sunfish, round goby, and rusty crayfish. Predators had either direct access to mussels and induced both TMII and DMII, or no direct access and induced only TMII through the presence of risk cues. In both sets of treatments, the predators induced a trophic cascade which resulted in more phytoplankton remaining with predators present than with only mussels present. The trophic cascade was weaker in three-predator and two-predator treatments than in one-predator treatments when predators had direct access to dreissenids (DMIIs and TMIIs). Crayfish had higher cascading effects on phytoplankton than both pumpkinseed and round goby. Increased predator diversity decreased the strength of DMIIs but had no effect on the strength of TMIIs. The strength of TMIIs was higher with zebra than quagga mussels. Our study suggests that inter-specific interference among predators in multi-species treatments weakens the consumptive cascading effects of predation on lower trophic levels whereas the importance of predator diversity on trait mediated effects depends on predator identity. © 2013 Naddafi and Rudstam.


De Riek J.,Belgium Institute for Agricultural and Fisheries Research | De Cock K.,Belgium Institute for Agricultural and Fisheries Research | Smulders M.J.M.,Wageningen UR Plant Breeding | Nybom H.,Swedish University of Agricultural Sciences
Molecular Phylogenetics and Evolution | Year: 2013

Within the genus Rosa numerous species have been described. Circumscription of the dogrose section Caninae is straightforward, but the delineation of species and subsections within this section is less clear, partly due to hybridisation between species. We have investigated the extent to which DNA marker-based information of wild populations corroborates present-day dogrose taxonomy and hypotheses about the origination of taxa. Sampling was conducted in a transect across Europe, collecting over 900 specimens of all encountered dogrose taxa. For comparison, we also included more than 200 samples of species belonging to other sections. Two lines of statistical analyses were used to investigate the genetic structure based on AFLP data: (1) an unstructured model with principal coordinate analysis and hierarchical clustering, and (2) a model with a superimposed taxonomic structure based on analysis of genetic diversity using a novel approach combining assignment tests with canonical discriminant analysis. Support was found for five of the seven subsections, whereas R. balsamica apparently belongs to subsection Caninae thus omitting the need for recognising subsection Tomentellae. For R. stylosa, a hybridogenic origin with a non-dogrose section member has been suggested, and it can be treated either as a separate subsection or within subsection Caninae. Within the subsection Rubigineae, a species cluster with low support for the taxa R. micrantha, R. rubiginosa and the putatively hybridogenous R. gremlii was identified. Similarly, several species in the subsection Caninae overlapped considerably, and are best regarded as one common species complex. This population genetic approach provides a general method to validate the taxonomic system in complex and polyploid taxa. © 2013 Elsevier Inc.


Rising A.,Karolinska Institutet | Rising A.,Swedish University of Agricultural Sciences
Acta Biomaterialia | Year: 2014

Recent biotechnological progress has enabled the production of spider silk proteins, spidroins, in heterologous hosts. Matrices based on recombinant spidroins support stem cell growth and are well tolerated when implanted in living tissue, thus the material is highly attractive for use in regenerative medicine. However, the matrices made are far from natural silk in terms of mechanical properties and are either spontaneously assembled, which results in heterogeneous products, or spun from harsh solvents with the concomitant risk of harmful remnants in the final products. If we could mimic the spider's aqueous silk spinning process we would likely obtain a material that had reproducible and better characteristics and that more easily could be transferred to clinical practice. Herein, the knowledge of the spiders' silk production system and the prerequisites for artificial spinning and assembly of recombinant proteins are reviewed and discussed in a biomedical context. © 2013 Acta Materialia Inc.


Hasund K.P.,Swedish University of Agricultural Sciences
Journal of Environmental Planning and Management | Year: 2011

This paper presents a methodology for developing state indicators, reflecting the provision of environmental public goods from agricultural landscapes. The methodology involves a structured use of meta-criteria and criteria for developing indicator variables and indicators, along with a coherent set of indicators. These indicators are aimed at providing a basis for determining agri-environmental payments to farmers. They are estimated at the object level, that is, per field or field element, so payments can be set that lead to an efficient resource allocation, structure of incentives and production. We find that, according to the criteria assessments for the Swedish agri-environmental situation, it is best to use a set of seven composite indicators on arable fields, permanent grasslands, linear elements, point elements, forest edges, bio-rich trees and relics. By estimating the indicators in two case study areas, we show that environmental services vary considerably between objects, indicating that value-differentiated payments may work as an efficient instrument in practical policy making. © 2011 University of Newcastle upon Tyne.


Bonnett B.N.,University of Guelph | Egenvall A.,Swedish University of Agricultural Sciences
Journal of Comparative Pathology | Year: 2010

From 1995 to the present Agria Animal Insurance, Sweden (Agria Djurförsäkring, Stockholm, Sweden) has provided data on both health care and life insurance claims for descriptive and analytical research. From these data we have published extensively on insured dogs and horses and have recently submitted a study on cat mortality. Over the periods studied most extensively (1995-2002 for dogs, 1997-2004 for horses and 1999-2006 for cats), Agria has insured approximately 200,000 dogs, 100,000 horses and up to 200,000 cats per year. Estimates based on formal research or market surveys suggest that Agria insures approximately 40% of both the Swedish dog and horse populations and 50% of the purebred cat population. Where animal insurance is so widely embraced, the Agria-insured populations are likely to be representative of the national population. This paper focuses on age patterns of disease, differences between breeds and genders, body system and disease process and changes over time. An increase in survival over the years for dogs and cats is undoubtedly affected by owner, societal and veterinary factors relative to the availability of, and willingness and ability to access, and continue, veterinary care. In addition, marked differences in survival across breeds suggest that comparisons between people and companion animals in terms of health, disease and longevity must consider these complexities. © 2009 Elsevier Ltd. All rights reserved.


Trubins R.,Swedish University of Agricultural Sciences
Land Use Policy | Year: 2013

Rural land-use in the European Union (EU) is strongly influenced by the Common Agricultural Policy (CAP) because it directly affects the relative profitability of different land-use options. Since 2000, the CAP has been heavily reformed. In particular, in Sweden, the 2003 CAP reform was followed by substantial shifts in agricultural land allocation. However, this land-use change has barely been studied empirically beyond the net changes of land-use categories. In order to better understand the transformation of the land-use system, all transitions between land-use categories and changes within existing categories need to be considered. This article presents an analysis of agricultural land-use change between 2002 and 2010 in a landscape in southern Sweden. The inter-category land transitions were identified and quantified by using a spatially explicit field-level resolution dataset. The intra-category change of utilization intensity was assessed for grasslands by using standard yields and forage consumption estimates. Substantial shifts in chains of connected inter-category land transitions were found between cereals, temporary grasses, permanent pastures and fallow lands. The grassland utilization analysis showed a growing gap between grassland area and forage consumption. These results indicate concentration of agricultural production to better quality land and a growing number of land-idling farms in the region. The CAP single farm payment scheme is discussed in the light of these findings. © 2013 Elsevier Ltd.


Levinsson A.,Swedish University of Agricultural Sciences
Arboriculture and Urban Forestry | Year: 2013

After transplanting, many trees enter a period of reduced growth that may limit their environmental and aesthetic benefits for several years. A number of nursery production methods have been developed in attempt to reduce root disturbance, which is often associated with the reduced growth. The main objective of this study was to investigate how five nursery production methods affect root systems and post-transplant shoot growth. Other objectives were the study of the effect of root structure (i.e., fibrous verses coarse) on trees' response to different production methods and the effect of the conditions at the transplanting site. Sweet cherry (Prunus avium L.) and red oak (Quercus rubra L.) with a stem circumference of 16-18 cm were produced as bare-rooted-, balled-and-burlapped-, root-pruned-, air-potted-, or fabric-container-grown trees, transplanted at two sites and studied for five seasons. Visual analysis showed that the production methods had clear effect on the root balls at transplanting. However, the differences were not clearly related to shoot growth. All transplanted red oaks, regardless of production method, showed significantly reduced shoot growth compared to pre-transplant growth. Balled and burlapped, root-pruned, and fabric-container-grown sweet cherry trees exhibited restored pre-transplant shoot growth three years after transplanting at the more favorable site. The results suggest that the fibrous-rooted sweet cherry was more responsive to production methods designed to reduce transplanting stress than the coarse-rooted red oak, and that site affected the time required for normal shoot growth to be regained. The results do not indicate that different sites require differently produced trees. © 2013 International Society of Arboriculture.


Ezebilo E.E.,Swedish University of Agricultural Sciences
International Journal of Biodiversity Science, Ecosystems Services and Management | Year: 2013

In most developing countries, there has been a long-standing conflict between nature conservation and local demands for natural resources. This paper reports a study on the preference of local people for different incentives that could help increase local support for nature conservation. It also explores the possibilities for designing a sustainable incentive strategy. Data were obtained from personal interviews conducted with community members around the Okwangwo Division of the Cross River National Park in south-east Nigeria, and were analysed using a multinomial logit model. The results showed that skill development was the most preferred incentive, followed by community forestry. The gathering of non-timber forest products under the supervision of national park officials was least preferred. The local people's preferences were influenced by factors such as education, extraction of bush mangoes, membership of environmental group, farmland size, income from non-timber forest products, ownership of commercial cocoa farms and gender. We conclude that an incentive-based strategy for nature conservation will be more effective if local people are more involved in negotiations regarding the incentive that are being offered. The findings from this study could assist nature conservation managers in designing a more acceptable and effective nature conservation strategy. © 2013 Copyright Taylor and Francis Group, LLC.


Bengtsson A.,Swedish University of Agricultural Sciences | Carlsson G.,Lund University
Urban Forestry and Urban Greening | Year: 2013

The present study aimed at describing older persons' experiences of outdoor environments at nursing homes in Sweden in terms of what factors are important and in what way they are important. Twelve residents and seven next of kin from three nursing homes participated in 16 interviews. Two main themes were identified. The first theme, access to nature and surrounding life, describes the outdoor environment as a means for change and as promoting a feeling of freedom. This theme calls for an inspiring design. The second theme, being comfortable in the outdoor environment, describes how important it is that going outdoors can be something easy and natural, and it calls for a comfortable design. The results are intended to facilitate practical knowledge that is useful to planners, decision-makers and care workers striving to create attractive and useable environments that are part of the daily life of nursing home residents. The themes also exemplify how the outdoor environment at nursing homes can serve as a resource in promoting restoration, a feeling of being at home and positive development late in life. © 2013 Elsevier GmbH.


Karltun E.,Swedish University of Agricultural Sciences | Lemenih M.,Hawassa University | Tolera M.,Hawassa University
Land Degradation and Development | Year: 2013

Farmers' perceptions of soil fertility change were compared with observations on soil quality changes and crop performance in soils from a chronosequence representing a range of soil ages since conversion from forest to cropland (0 to 57years). A majority of the farmers, 92 per cent, had observed a decline in soil fertility on their land. Farmers use crop yield, indicator plants, soil softness and soil colour to judge soil fertility. They identified 11 plants that they used to indicate high soil fertility and four plants that they used to indicate low soil fertility. There was a strong correlation (r=0·96) between soil organic matter content (loss on ignition) and farmers' ranking of soil fertility based on colour and softness of soil samples from the chronosequence. The biotest experiment with maize showed an exponential decline in biomass production along the chronosequence, confirming the results of farmers' soil fertility ranking. In the biotest, total soil N predicted produced biomass well (r2=0·95), whereas the relationship with soil available P (Olsen) was less obvious. Among the eight analysed plant nutrients in the maize leaves, N content was found to correlate best with biomass production (r2=0·94). We conclude (i) that there is good agreement between farmers' knowledge and scientific indicators of soil fertility and (ii) that the major reason for declining soil fertility in Beseku is the decrease in N mineralization over time. Interventions should focus on supporting farmers to implement a diversified nutrient management strategy that can maintain or increase long-term productivity of the soil. © 2011 John Wiley & Sons, Ltd.


Simonsen R.,Swedish University of Agricultural Sciences
Silva Fennica | Year: 2013

In thisstudy the profitability of regenerating Scots pine (Pinus sylvestris L.) was examined for two methods; planting and natural regeneration with seed trees. The methods were modelled on stand level and optimised numerically using nonlinear optimisation. The analysis includes 7 site indexes, 16 to 28 expressed as dominant height in meters at an age of 100 years; and 8 localities in northern Sweden distributed on two latitudes, 60°N and 64°N and four altitudes, 100 to 400m.a.s.l. Furthermore, two scenarios of genetically improved planting material were examined. The results show that the optimal choice of regeneration method depends on the location, site index and discount rate. Considering the same genetic regeneration material, natural regeneration was the optimal method for most of the evaluated sites. Planting was optimal only for stands of high site index and low rate of seedling mortality, which is associated with localities on low altitudes. The break even site index, where the two methods yielded the same net present value, was 27 on average (25 to 28). The choice between the two regeneration methods wasfound to be more economically important when the discount rate waslow and for low site indexes. The option of using genetically improved plant material shift the preference towards planting. Thus, the two levels of genetic gain of +4% and +10% to maximum mean annual increment resulted in an average break even site index of 25 and 21 respectively.


Odeen A.,Uppsala University | Hastad O.,Swedish University of Agricultural Sciences
BMC Evolutionary Biology | Year: 2013

Background: Colour vision in birds can be categorized into two classes, the ultraviolet (UVS) and violet sensitive (VS). Their phylogenetic distributions have traditionally been regarded as highly conserved. However, the complicated nature of acquiring spectral sensitivities from cone photoreceptors meant that until recently, only a few species had actually been studied. Whether birds are UVS or VS can nowadays be inferred from a wide range of species via genomic sequencing of the UV/violet SWS1 cone opsin gene. Results: We present genomic sequencing results of the SWS1 gene from 21 avian orders. Amino acid residues signifying UV sensitivity are found in the two most important spectral tuning sites 86 and 90 of Pteroclidiformes and Coraciiformes, in addition to the major clades, Palaeognathae, Charadriiformes, Trogoniformes, Psittaciformes and Passeriformes, where they where previously known to occur. We confirm that the presumed UVS-conferring amino acid combination F86, C90 and M93 is common to Palaeognathae and unique to this clade, despite available spectrometric evidence showing the ostrich retina to be VS. Conclusions: By mapping our results together with data from previous studies on a molecular phylogeny we show that avian colour vision shifted between VS and UVS at least 14 times. Single nucleotide substitutions can explain all these shifts. The common ancestor of birds most likely had a VS phenotype. However, the ancestral state of the avian SWS1 opsin's spectral tuning sites cannot be resolved, since the Palaeognathae are F86, C90 while the Neognathae are ancestrally S86, S90. The phylogenetic distribution of UVS and VS colour vision in birds is so complex that inferences of spectral sensitivities from closely related taxa should be used with caution. © 2013 Ödeen and Håstad; licensee BioMed Central Ltd.


Hall H.,University of British Columbia | Hall H.,Swedish University of Agricultural Sciences | Ellis B.,University of British Columbia
BMC Plant Biology | Year: 2013

Background: Plant cell walls are complex dynamic structures that play a vital role in coordinating the directional growth of plant tissues. The rapid elongation of the inflorescence stem in the model plant Arabidopsis thaliana is accompanied by radical changes in cell wall structure and chemistry, but analysis of the underlying mechanisms and identification of the genes that are involved has been hampered by difficulties in accurately sampling discrete developmental states along the developing stem.Results: By creating stem growth kinematic profiles for individual expanding Arabidopsis stems we have been able to harvest and pool developmentally-matched tissue samples, and to use these for comparative analysis of global transcript profiles at four distinct phases of stem growth: the period of elongation rate increase, the point of maximum growth rate, the point of stem growth cessation and the fully matured stem. The resulting profiles identify numerous genes whose expression is affected as the stem tissues pass through these defined growth transitions, including both novel loci and genes identified in earlier studies. Of particular note is the preponderance of highly active genes associated with secondary cell wall deposition in the region of stem growth cessation, and of genes associated with defence and stress responses in the fully mature stem.Conclusions: The use of growth kinematic profiling to create tissue samples that are accurately positioned along the expansion growth continuum of Arabidopsis inflorescence stems establishes a new standard for transcript profiling analyses of such tissues. The resulting expression profiles identify a substantial number of genes whose expression is correlated for the first time with rapid cell wall extension and subsequent fortification, and thus provide an important new resource for plant biologists interested in gene discovery related to plant biomass accumulation. © 2013 Hall and Ellis; licensee BioMed Central Ltd.


Hasund K.P.,Swedish University of Agricultural Sciences
Land Use Policy | Year: 2013

Biodiversity, cultural heritage, and scenery are major public goods produced in the agricultural landscape. Theoretically, Indicator-based Agri-Environmental Payments have the properties of providing socially efficient production. A system of seven composite state indicators, expressing the public goods of the respective fields or field elements, was developed and tested to assess if the model worked in practical policy implementation. The evaluation indicated a more efficient resource allocation, better dynamic incentives and lower transaction costs, compared to the current Swedish payment programs. A disadvantage is that such value-differentiated payments do not comply with tailoring and with present WTO- or CAP-regulations of cost-based payments. © 2012 Elsevier Ltd.


Folkeson L.,Swedish Road and Transport Research Institute | Antonson H.,VTI | Helldin J.O.,Swedish University of Agricultural Sciences
Land Use Policy | Year: 2013

Cumulative effects (CE) still receive little attention in the Swedish processes for road and railway infrastructure planning. This article seeks to analyse how CE are treated by professionals engaged in Environmental Impact Assessment (EIA) and Strategic Environmental Assessment of roads and railways. The aims were (i) to analyse views of CE held by professionals with long planning practice, (ii) to analyse how planners experience the handling of CE in their daily planning practice, and (iii) to identify means to strengthen the assessment of CE in the Swedish road and railway planning process. The study was performed as an international literature review and two focus groups among planners. Discussions revealed little knowledge and use of the term CE, partly due to lack of incentives and guidance. Little mention was made of research. Participants said EIA work was much directed towards the environmental compartments/aspects listed in the Environmental Code. Environmental impacts designated as significant demanded much work. The discussions revealed a need of more collaboration between various actors in EIA and of novel methods of public participation. Spatial and temporal scales were chosen with little concern of CE. The European Landscape Convention was hoped to enhance CE treatment in EIA. Improvement suggestions include (i) use of the term CE in regulatory instruments, (ii) development of the interplay between CEA practice and CE science, (iii) co-ordination of management of baseline, monitoring and follow-up data, (iv) assessment of CE in relation to project-specific environmental objectives, developed in a bottom-up process, (v) inclusion of CE, within and across environmental aspects, in determining the significance of environmental impacts, (vi) advice on CE treatment in EIA guidelines, (vii) requirement of CE assessment in EIA procurement, (viii) strengthened generalist competence in environmental assessment, and (ix) enhancing skills in stepwise analyses and indirect environmental effects. Research needs include adaptation of the Swedish EIA procedure to international state of the art, knowledge support of quantification in CE assessment, and development of innovative means of public consultation in transport infrastructure planning. © 2012 Elsevier Ltd.


Kapralov M.V.,University of Oxford | Kubien D.S.,University of New Brunswick | Andersson I.,Swedish University of Agricultural Sciences | Filatov D.A.,University of Oxford
Molecular Biology and Evolution | Year: 2011

Rubisco, the primary photosynthetic carboxylase, evolved 3-4 billion years ago in an anaerobic, high CO 2 atmosphere. The combined effect of low CO 2 and high O 2 levels in the modern atmosphere, and the inability of Rubisco to distinguish completely between CO 2 and O 2, leads to the occurrence of an oxygenation reaction that reduces the efficiency of photosynthesis. Among land plants, C 4 photosynthesis largely solves this problem by facilitating a high CO 2/O 2 ratio at the site of Rubisco that resembles the atmosphere in which the ancestral enzyme evolved. The prediction that such conditions favor Rubiscos with higher kcatCO 2 and lower CO 2/O 2 specificity (SC/O) is well supported, but the structural basis for the differences between C 3 and C 4 Rubiscos is not clear. Flaveria (Asteraceae) includes C 3, C 3-C 4 intermediate, and C 4 species with kinetically distinct Rubiscos, providing a powerful system in which to study the biochemical transition of Rubisco during the evolution from C 3 to C 4 photosynthesis. We analyzed the molecular evolution of chloroplast rbcL and nuclear rbcS genes encoding the large subunit (LSu) and small subunit (SSu) of Rubisco from 15 Flaveria species. We demonstrate positive selection on both subunits, although selection is much stronger on the LSu. In Flaveria, two positively selected LSu amino acid substitutions, M309I and D149A, distinguish C 4 Rubiscos from the ancestral C 3 species and statistically account for much of the kinetic difference between the two groups. However, although Flaveria lacks a characteristic "C 4" SSu, our data suggest that specific residue substitutions in the SSu are correlated with the kinetic properties of Rubisco in this genus. © 2010 The Author.


Gibb H.,La Trobe University | Gibb H.,Swedish University of Agricultural Sciences
Ecology | Year: 2011

Habitat succession is thought to influence the importance of competition in assemblages. Competitive interactions are considered of critical importance in structuring ant assemblages, but field experiments show varied effects. I tested how succession in managed boreal forests affects the outcome of competition from dominant red wood ants, Formica aquilonia, through a removal experiment in replicated stands of three different ages (0-4, 30- 40, and 80-100 years old). F. aquilonia abundance was reduced by 87%, and procedural controls showed no nontarget effects. The succession gradient revealed the full range of possible responses from ant species: decreases in 1-4-year-old stands, increases in 30-40-yearold stands, and no effects in 80-100-year-old stands, where diversity was lowest. Habitat succession thus regulates competitive interactions in this system. I propose a model for this system, where competitive effects depend on time since disturbance. In this case, soon after disturbance the dominant species facilitates increases in the abundance of other species. At intermediate times, competition reduces the abundance of some species. Finally, in longundisturbed habitats, competitors may fail to evolve, particularly in high-stress environments. Interactions between competition and habitat succession may explain why structuring effects of ecologically dominant species appear inconsistent. © 2011 by the Ecological Society of America.


Jones B.,University of Sydney | Ljung K.,Swedish University of Agricultural Sciences
Current Opinion in Plant Biology | Year: 2012

The colonisation of terrestrial environments offered plants a host of advantages. It also presented them with major challenges. The foremost amongst these, the dichotomous nature of terrestrial environments, was clearly successfully met by the development of an integrated but divergent root-shoot structure. Whereas they share many similarities, roots and shoots evolved specialist functions in line with their principle roles and their growth environment. In this review, we discuss a number of areas where recent discoveries, principally in Arabidopsis, are shedding light on the mechanisms that enable the successful colonisation of the soil environment. © 2011 Elsevier Ltd.


Oni S.K.,Trent University | Futter M.N.,Swedish University of Agricultural Sciences | Dillon P.J.,Trent University
Journal of Great Lakes Research | Year: 2011

We present an application of the Integrated Catchments model for Carbon (INCA-C) to simulate dissolved organic carbon (DOC) dynamics in two main tributaries of Lake Simcoe. This is the first application of the INCA-C model to a large watershed with mixed agricultural, urban and forest land use. Understanding DOC dynamics in the Lake Simcoe watershed will aid in understanding the spatial and temporal patterns of organic and metal contaminant transport in the watershed which should, in turn, lead to improved watershed management. We were able to successfully simulate flows in the Beaver River and to capture the seasonal and inter-annual patterns in DOC concentration in the Beaver and White Creeks, two of Lake Simcoe's major tributaries. Sensitivity analysis showed the importance of hydrology and land use in controlling surface water DOC. The success of the model application presented here suggests that some of the same processes which control DOC in headwater watersheds are also operating in larger river basins. © 2010 Elsevier B.V.


Kronholm T.,Swedish University of Agricultural Sciences
Small-scale Forestry | Year: 2016

This paper examines how Swedish forest owners’ associations are adapting their strategies to fit the changing needs of current and future members, and assesses how this development affects the organizations’ profile and relationship with members. To explore this issue eight semi-structured, face-to-face interviews with chairmen and senior managers from three associations and the Federation of Swedish Family Forest Owners were performed. Results showed that associations have identified an increasing need for management-support activities among members due to their decreasing familiarity with the basics of forestry. Help is increasingly needed both for setting up goals and objectives for their forest ownership, and to practically manage their properties. The associations’ education programmes are also being improved and adapted to suit members’ varying understanding of forestry by the introduction of A-, B- and C-level courses. Education campaigns have proved to be a successful tool for affecting members’ management objectives. Further, the associations see an increasing need for political activity to counter calls for stricter management regulations being made by the media, politicians and environmental organizations and thereby protect members’ ownership rights. Initiatives within the organizations for more efficient governance processes and the professionalization of working procedures within the member organizations may, however, come to reduce individual member involvement in the associations. Members may thus increasingly come to act as customers of service in their interaction with the organizations. © 2016 Steve Harrison, John Herbohn


Bryhn A.C.,Uppsala University | Bryhn A.C.,Swedish University of Agricultural Sciences
Journal of Environmental Engineering (United States) | Year: 2012

Environmental conflicts of interest are important to account for when environmental policies are designed. This paper explores the quantitative connection between urban wastewater treatment, coastal eutrophication, and fish biomass in the mesotrophic Gulf of Riga (northern Europe). The probable effect on the water quality from one clearly defined abatement measure, improved urban sewage treatment, has been studied. The implementation cost and the likely effect on total fish biomass also have been assessed. Computer simulations by using the previously published model CoastMab suggested that good water quality according to the European Union (EU Marine) Strategy Framework Directive could be achieved if urban sewage treatment would be upgraded to Nordic and German standards, and not only around the Gulf of Riga but also in the whole Baltic Sea drainage basin. The Secchi depth would double according to these simulations, whereas total phosphorus and summer chlorophyll concentrations would decrease by 54% and 53%, respectively. The total fish biomass should be expected to decrease by approximately 42% if good water quality (as defined in EU directives) should be achieved. However, changes in total fish biomass also could be offset by changes in other important determinants, such as climate-related variables or fishing pressure. The study estimated that it could take approximately 20-40 years after abatement action for the trophic state in the Gulf to stabilise again. Upgrading urban sewage treatment to this extent would cost 468-1,118 million Euro per year. Treatment could have substantial positive effects on the water quality of the Gulf but could also have adverse side effects on the total fish biomass. © 2012 American Society of Civil Engineers.


Lindberg E.,Swedish University of Agricultural Sciences | Hollaus M.,Vienna University of Technology
Remote Sensing | Year: 2012

This study compares methods to estimate stem volume, stem number and basal area from Airborne Laser Scanning (ALS) data for 68 field plots in a hemi-boreal, spruce dominated forest (Lat. 58°N, Long. 13°E). The stem volume was estimated with five different regression models: one model based on height and density metrics from the ALS data derived from the whole field plot, two models based on similar combinations derived from 0.5 m raster cells, and two models based on canopy volumes from the ALS data. The best result was achieved with a model based on height and density metrics derived from 0.5 m raster cells (Root Mean Square Error or RMSE 37.3%) and the worst with a model based on height and density metrics derived from the whole field plot (RMSE 41.9%). The stem number and the basal area were estimated with: (i) area-based regression models using height and density metrics from the ALS data; and (ii) single tree-based information derived from local maxima in a normalized digital surface model (nDSM) mean filtered with different conditions. The estimates from the regression model were more accurate (RMSE 52.7% for stem number and 21.5% for basal area) than those derived from the nDSM (RMSE 63.4%-91.9% and 57.0%-175.5%, respectively). The accuracy of the estimates from the nDSM varied depending on the filter size and the conditions of the applied filter. This suggests that conditional filtering is useful but sensitive to the conditions. © 2012 by the authors.


Skarin H.,National Veterinary Institute SVA | Skarin H.,Swedish University of Agricultural Sciences | Hafstrom T.,National Veterinary Institute SVA | Westerberg J.,National Veterinary Institute SVA | Segerman B.,National Veterinary Institute SVA
BMC Genomics | Year: 2011

Background: Clostridium botulinum strains can be divided into four physiological groups that are sufficiently diverged to be considered as separate species. Here we present the first complete genome of a C. botulinum strain from physiological group III, causing animal botulism. We also compare the sequence to three new draft genomes from the same physiological group.Results: The 2.77 Mb chromosome was highly conserved between the isolates and also closely related to that of C. novyi. However, the sequence was very different from the human C. botulinum group genomes. Replication-directed translocations were rare and conservation of synteny was high. The largest difference between C. botulinum group III isolates occurred within their surprisingly large plasmidomes and in the pattern of mobile elements insertions. Five plasmids, constituting 13.5% of the total genetic material, were present in the completed genome. Interestingly, the set of plasmids differed compared to other isolates. The largest plasmid, the botulinum-neurotoxin carrying prophage, was conserved at a level similar to that of the chromosome while the medium-sized plasmids seemed to be undergoing faster genetic drift. These plasmids also contained more mobile elements than other replicons. Several toxins and resistance genes were identified, many of which were located on the plasmids.Conclusions: The completion of the genome of C. botulinum group III has revealed it to be a genome with dual identity. It belongs to the pathogenic species C. botulinum, but as a genotypic species it should also include C. novyi and C. haemolyticum. The genotypic species share a conserved chromosomal core that can be transformed into various pathogenic variants by modulation of the highly plastic plasmidome. © 2011 Skarin et al; licensee BioMed Central Ltd.


Hard T.,Swedish University of Agricultural Sciences
FEBS Journal | Year: 2011

The molecular biology underlying protein aggregation and neuronal death in Alzheimer's disease is not yet completely understood, but small soluble nonamyloid aggregates of the amyloid β-protein (Aβ) have been shown to play a fundamental neurotoxic role. The composition and biological action of such aggregates, known as oligomers and protofibrils, are therefore areas of intense study. However, research is complicated by the multitude of different interconverting aggregates that Aβ can form in vitro and in vivo, and by the inhomogeneity and instability of in vitro preparations. Here we review recent studies in which protein engineering, and in particular disulfide engineering, has been applied to stabilize different Aβ aggregates. For example, several techniques now exist to obtain stable and neurotoxic protofibrillar forms of Aβ, and engineered Aβ dimers, or larger aggregates formed by these, have been shown to specifically induce neuronal damage in a way that mimics Alzheimer's disease pathology. Disulfide engineering has also revealed structural properties of neurotoxic aggregates, for instance that Aβ in protofibrils and globular oligomers adopts a β-hairpin conformation that is similar to, but topologically distinct from, the conformation of Aβ in mature amyloid fibrils. Protein engineering is therefore a workable strategy to address many of the outstanding questions relating to the structure, interconversion and biological effects of oligomers and protofibrils of Aβ. Oligomeric aggregates of the amyloid β-protein (Aβ) have been shown to play a fundamental neurotoxic role in Alzheimer's disease. However, research is complicated by the multitude of different interconverting aggregates that Aβ can form in vitro and in vivo, and by the inhomogeneity and instability of in vitro preparations. Here we review recent studies in which protein engineering, and in particular disulfide engineering, has been applied to stabilize different Aβ aggregates. © 2011 The Author Journal compilation.


Weslien J.,Forestry Research Institute of Sweden | Djupstrom L.B.,Forestry Research Institute of Sweden | Schroeder M.,Swedish University of Agricultural Sciences | Widenfalk O.,Forestry Research Institute of Sweden
Journal of Animal Ecology | Year: 2011

1.Priority effects have been hypothesized to have long-lasting impact on community structure in natural ecosystems. Long-term studies of priority effects in natural ecosystems are however sparse, especially in terrestrial ecosystems. 2.Wood decay is a slow process involving a high diversity of insect and fungus species. Species interactions that drive change in communities of insects and fungi during wood decay are poorly understood because of a lack of sufficient long-term studies. 3.In this paper, we followed the colonization and succession of wood-living insects and fungi on cut trees during 15years, from tree death and onwards, in a boreal forest landscape. We test the long-term priority effects hypothesis that the identity and abundance of species that colonize first affect the colonization success of later-arriving species. We also hypothesize that species interact in both facilitative and inhibitory ways, which ultimately affect habitat quality for a red-listed late-succession beetle species. 4.Possible causal associations between species were explored by path analysis. The results indicate that one bark beetle species, Hylurgops palliatus, and one wood-borer species, Monochamus sutor, which colonized the wood during the first year after cutting, influenced the occurrence of a rare, wood-living beetle, Peltis grossa, that started to emerge from the stumps about 10years later. The positive effects of Hylurgops palliatus and negative effects of M. sutor were largely mediated through the wood-decaying fungus species Fomitopsis pinicola. 5.The study shows that variable priority effects may have long-lasting impact on community assembly in decaying wood. The study also exemplifies new possibilities for managing populations of threatened species by exploring links between early, well-understood species guilds and late, more poorly understood species guilds. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.


Baum S.,Johann Heinrich Von Thunen Institute | Bolte A.,Johann Heinrich Von Thunen Institute | Weih M.,Swedish University of Agricultural Sciences
GCB Bioenergy | Year: 2012

The demand for wood from short rotation coppice (SRC) plantations as a renewable energy source is currently increasing and could affect biodiversity in agricultural areas. The objective was to evaluate the contribution of SRC plantations to phytodiversity in agricultural landscapes assessed as species richness, species-area relationships, Shannon indices, detrended correspondence analysis on species composition, Sørensen similarities, habitat preference proportions, and species proportions found in only one land use. Vegetation surveys were conducted on 12 willow (Salix spp.) and three poplar (Populus spp.) coppice sites as well as on surrounding arable lands, grasslands and forests in central Sweden and northern Germany. SRC plantations were richer in plant species (mean: 30 species per 100 m 2) than arable land (10), coniferous forests (13) and mixed forests in Germany (12). Comparing SRC plantations with other land uses, we found lowest similarities in species composition with arable lands, coniferous forests and German mixed forests and highest similarities with marginal grassland strips, grasslands and Swedish mixed forests. Similarity depended on the SRC tree cover: at increased tree cover, SRC plantations became less similar to grasslands but more similar to forests. The SRC plantations were composed of a mixture of grassland (33%), ruderal (24%) and woodland (15%) species. Species abundance in SRC plantations was more heterogeneous than in arable lands. We conclude that SRC plantations form novel habitats leading to different plant species composition compared to conventional land uses. Their landscape-scale value for phytodiversity changes depending on harvest cycles and over time. As a structural landscape element, SRC plantations contribute positively to phytodiversity in rural areas, especially in land use mosaics where these plantations are admixed to other land uses with dissimilar plant species composition such as arable land, coniferous forest and, at the German sites, also mixed forest. © 2012 Blackwell Publishing Ltd.


Jagerstad M.,Swedish University of Agricultural Sciences
Acta Paediatrica, International Journal of Paediatrics | Year: 2012

The prevalence of neural tube defect (NTD)-affected pregnancies ranges between 0.4 and 2/1000 pregnancies in EU. NTDs result in severe malformations and sometimes miscarriages. Children born with NTD suffer for the rest of their life of disability and chronic healthcare issues, and many women therefore choose termination of pregnancy if NTD is diagnosed prenatally. Women planning for pregnancy are recommended to eat 400 μg folic acid/d, whereas average figures across Europe indicate intakes of ∼250 μg/d for women of fertile age, a gap that could be bridged by implementation of folic acid fortification. The results of mandatory folic acid fortifications introduced in USA and Canada are a decrease between 25 and 45% of NTD pregnancies. Conclusion: Evidence-based NTD prophylaxis is now practised in more than 60 countries worldwide. EU countries worry over possible cancer risks, but ignore a wealth of studies reporting decreasing cancer risks with folate intakes at recommended levels. Currently, there are indications of a U-shaped relationship, that is, higher cancer risks at low folate intakes (<150 μg/day) and highly elevated folate intakes (>1 mg/day), respectively. However neither the global World Cancer Research review nor EU's European Food Safety Authority report present data on increased cancer risk at physiological folate intake levels. Therefore, EU should act to implement folic acid fortification as NTD prophylaxis as soon as possible. © 2012 Foundation Acta Pædiatrica.


Keller T.,Agroscope Reckenholz Tnikon Research Station ART | Keller T.,Swedish University of Agricultural Sciences | Dexter A.R.,Institute of Soil Science and Plant Cultivation IUNG PIB
Soil Research | Year: 2012

The plastic limits (lower plastic limit, PL; and liquid limit, LL) are important soil properties that can yield information on soil mechanical behaviour. The objective of this paper is to study the plastic limits of agricultural soils as functions of soil texture and organic matter (OM) content. The plastic limits were highly related to the clay content. The LL was more strongly correlated with clay than was PL, but the reasons are unclear. Interestingly, PL was virtually unaffected by clay content for soils with clay contents below ∼35%. The OM had a strong effect on the plastic limits. This effect was clearly demonstrated when analysing soils of similar texture with a range of OM. We present equations (pedotransfer functions) for estimation of PL, LL, and plasticity index (PI) from soil texture and OM. Finally, we predict that the clay content must be <10% for soils without OM to be plastic; however, soils with 10% clay can be plastic if OM is present. More research is needed to investigate OM effects on soil consistency. © CSIRO 2012.


Ockinger E.,Lund University | Ockinger E.,Swedish University of Agricultural Sciences | Nilsson S.G.,Lund University
Ecology | Year: 2010

The population dynamics of organisms living in short-lived habitats will largely depend on the turnover of habitat patches. It has been suggested that epiphytes, whose host plants can be regarded as habitat patches, often form such patch-tracking populations. However, very little is known about the long-term fate of epiphyte individuals and populations. We estimated life span and assessed environmental factors influencing changes in vitality, fertility, abundance, and distribution of the epiphytic lichen species Lobaria pulmonaria on two spatial scales, individual trees and forest patches, over a period of ∼10 years in 66 old-growth forest fragments. The lichen had gone extinct from 7 of the 66 sites (13.0%) where it was found 10 years earlier, even though the sites remained unchanged. The risk of local population extinction increased with decreasing population size. In contrast to the decrease in the number of occupied trees and sites, the mean area of the lichen per tree increased by 43.0%. The number of trees with fertile ramets of L. pulmonaria increased from 7 (∼1%) to 61 (∼ 10%) trees, and the number of forest fragments with fertile ramets increased from 4 to 23 fragments. The mean annual rate of L. pulmonaria extinction at the tree level was estimated to be 2.52%, translating into an expected lifetime of 39.7 years. This disappearance rate is higher than estimated mortality rates for potential host trees. The risk of extinction at the tree level was significantly positively related to tree circumference and differed between tree species. The probability of presence of fertile ramets increased significantly with local population size. Our results show a long expected lifetime of Lobaria pulmonaria ramets on individual trees and a recent increase in vitality, probably due to decreasing air pollution. The population is, however, declining slowly even though remaining stands are left uncut, which we interpret as an extinction debt. © 2010 by the Ecological Society of America.


Morrell J.M.,Swedish University of Agricultural Sciences | Wallgren M.,Quality Genetics
Reproduction in Domestic Animals | Year: 2011

Contents: Colloid centrifugation of boar semen has been reported sporadically for at least the last two decades, beginning with density gradient centrifugation (DGC) and progressing more recently to single layer centrifugation (SLC). Single layer centrifugation through a species-specific colloid has been shown to be effective in selecting the best spermatozoa (spermatozoa with good motility and normal morphology) from boar sperm samples. The method is easier to use and less time-consuming than DGC and has been scaled-up to allow whole ejaculates from other species, e.g. stallions, to be processed in a practical manner. The SLC technique is described, and various scale-up versions are presented. The potential applications for SLC in boar semen preservation are as follows: to improve sperm quality in artificial insemination (AI) doses for 'problem' boars; to increase the shelf-life of normal stored sperm samples, ei