Norwegian Forest And Landscape Institute
Norwegian Forest And Landscape Institute
The Norwegian Forest and Landscape Institute is a research institute based in Norway.Organizationally subordinate to the Norwegian Ministry of Agriculture and Food, it is autonomous in its research. It was established on 1 July 2006 through a merger of the Norwegian Forest Research Institute and the Norwegian Institute of Land Inventory . Headquarters are in Ås, and regional offices are in Bergen, Steinkjer and Tromsø.The director is Arne Bardalen. Wikipedia.
Lahr E.C.,University of Montana |
Krokene P.,Norwegian Forest And Landscape Institute
PLoS ONE | Year: 2013
Bark beetles and associated fungi are among the greatest natural threats to conifers worldwide. Conifers have potent defenses, but resistance to beetles and fungal pathogens may be reduced if tree stored resources are consumed by fungi rather than used for tree defense. Here, we assessed the relationship between tree stored resources and resistance to Ceratocystis polonica, a phytopathogenic fungus vectored by the spruce bark beetle Ips typographus. We measured phloem and sapwood nitrogen, non-structural carbohydrates (NSC), and lipids before and after trees were attacked by I. typographus (vectoring C. polonica) or artificially inoculated with C. polonica alone. Tree resistance was assessed by measuring phloem lesions and the proportion of necrotic phloem around the tree's circumference following attack or inoculation. While initial resource concentrations were unrelated to tree resistance to C. polonica, over time, phloem NSC and sapwood lipids declined in the trees inoculated with C. polonica. Greater resource declines correlated with less resistant trees (trees with larger lesions or more necrotic phloem), suggesting that resource depletion may be caused by fungal consumption rather than tree resistance. Ips typographus may then benefit indirectly from reduced tree defenses caused by fungal resource uptake. Our research on tree stored resources represents a novel way of understanding bark beetle-fungal-conifer interactions. © 2013 Lahr, Krokene.
Devlin G.,University College Dublin |
Talbot B.,Norwegian Forest And Landscape Institute
Applied Energy | Year: 2014
The Irish government has undertaken to reduce national CO2 emissions through a range of measures put out in their Biomass Action Plan and the National Renewable Energy Action Plan. The conversion of peat fired power plants to co-fire with renewable biomass is one of these. This paper considers how the adoption of sweeping policies impact on other actors presently supplying or utilizing woody biomass resources. The SAWMILL sector (18 sawmills), BOARD sector, 3 board plants, and ENERGY sector (3 peat fired power stations) were included in a Linear Programming (LP) based transportation study. Specific transport costs between each residue producing sawmill and each board and energy plant were modeled and used in finding the minimum delivered cost for a number of scenarios. Scenario 2015 represented the status quo, while Scenario 2030 represented a situation with 30% co-firing with woody biomass equivalents in the energy plants. For each time horizon, the problem was solved from the perspective of society at large (GLOBAL), for the benefit of the board sector (BOARD) or with emphasis on minimizing the cost to the energy sector (ENERGY). The cost of transporting alternative sources of renewable energy was varied between €100 and €500TJ-1. Results showed how overall supply costs increase with increasing alternative energy cost, but also how the dynamics between sectors focus worked. The cost of transport to the Energy sector ranged from €306,043 to €996,842 in Scenario 2015, while the increased demand in 2030 led to a range of between €1,132,831 and €4,926,040, depending on the alternative cost selected. For the Board sector, whose absolute demand remained constant, the total transport cost ranged between €868,506 and €3,454,916 in Scenario 2015. The unchanged demand showed that the transport costs also remained the same for the 2030 Scenario, however, the optimization focusing on the Energy sector, increased the delivery cost to the Board sector by up to €693,730 per year by 2015 and €842,271 per year by 2030, indicating how intervention would be necessary if political ambitions of a 30% co-firing should happen without detriment to other important wood based industries. © 2013.
Wegge P.,Norwegian University of Life Sciences |
Rolstad J.,Norwegian Forest And Landscape Institute
Forest Ecology and Management | Year: 2011
Along the succession gradient of the boreal forest ecosystem, black grouse Tetrao tetrix inhabits the early and capercaillie Tetrao urogallus the latest stages. When converting old forest to clearcuts and plantations, commercial forestry has therefore been assumed to affect capercaillie negatively and to be favourable to black grouse. During a 30-year period (1979-2008) we monitored sympatric populations of the two species in a forest in southeast Norway based on annual spring and autumn censuses and radio-marked birds. During this period, the proportion of old, semi-natural forest was halved and clearcuts and young plantations increased accordingly. The grouse populations did not change as predicted. While the trend in August numbers of adult black grouse declined, males more than females, abundance of adult capercaillie remained unchanged. Number of males at leks showed similar patterns. Equally surprising, breeding success (number of chicks per female in August) of both species increased, thus indicating that the populations were regulated more by variation in adult survivorship than by recruitment of young birds. No correlations were found with changing climatic factors (precipitation and temperatures in winter and spring, snow depth and time of snow melt), except that year-to-year breeding success was positively correlated with minimum temperatures during 2 weeks posthatch. The results are explained by a combination of more flexible habitat selection than previously assumed and a changing predator regime: In the early period, nearly all capercaillie leks were located in old, semi-natural forest, but as plantations grew older (>30 years), new leks were established there. Similarly, while young capercaillie broods used old semi-natural forest almost exclusively when the study started, they frequently used middle-aged plantations, especially those with a ground cover of bilberry Vaccinium myrtillus, when these became common in later years. The increasing breeding success could largely be explained by more females rearing chicks successfully, presumably due to a marked decline in the main nest predator, the red fox Vulpes vulpes. A practice of thinning of the old, semi-natural forest some years prior to final harvesting probably facilitated predation of black grouse by goshawks Accipiter gentilis. Contrary to many beliefs, our results indicate that both capercaillie and black grouse are quite tolerant to changes in forest management regimes. In our study, numerical and functional responses of predators (mainly red fox and goshawk) apparently played a more important role in regulating grouse numbers than habitat factors per se. © 2011 Elsevier B.V.
Tveite B.,Norwegian Forest And Landscape Institute |
Hanssen K.H.,Norwegian Forest And Landscape Institute
Forest Ecology and Management | Year: 2013
The relative volume growth effects of thinning after whole-tree harvesting (WTH) compared to a conventional stem-only harvest (CH) in young stands of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) were analyzed, using a series of four pine and four spruce field experiments. The series was established in the years 1972-1977, and thinning was performed only once.Results are shown periodically and cumulatively. All sites were included for 20 (19) years in pine and 25. years in spruce. The total experimental period varied between 19 and 35. years for individual sites.Four models assuming additive or multiplicative effects gave only slightly varying results. The inclusion of standing volume after thinning as a covariate was effective in spruce independent of whether the covariate was treated as multiplicative or additive. A logarithmic model with a multiplicative effect of the covariate was preferred in further presentations.Results for pine stands after 20. years indicated a nonsignificant loss of 5% with confidence limits (p= 0.05) of ±6-7%, while the spruce stands showed a significant growth loss of 11% with confidence limits of ±4-5% after 25. years. The difference between the species in relative growth effects was significant, and amounted to 8% for a cumulative 20-year period.No indications of trends in response were found during a 20-year period in pine and a 25-year period in spruce.An analysis of growth effects in the first years showed that basal area increment in spruce was significantly reduced already in the first growing season after thinning. © 2013 Elsevier B.V.
Breidenbach J.,Norwegian Forest And Landscape Institute |
Astrup R.,Norwegian Forest And Landscape Institute
European Journal of Forest Research | Year: 2012
The Norwegian National Forest Inventory (NNFI) provides estimates of forest parameters on national and regional scales by means of a systematic network of permanent sample plots. One of the biggest challenges for the NNFI is the interest in forest attribute information for small sub-populations such as municipalities or protected areas. Frequently, too few sampled observations are available for such small areas to allow estimates with acceptable precision. However, if an auxiliary variable exists that is correlated with the variable of interest, small area estimation (SAE) techniques may provide means to improve the precision of estimates. The study aimed at estimating the mean above-ground forest biomass for small areas with high precision and accuracy, using SAE techniques. For this purpose, the simple random sampling (SRS) estimator, the generalized regression (GREG) estimator, and the unit-level empirical best linear unbiased prediction (EBLUP) estimator were compared. Mean canopy height obtained from a photogrammetric canopy height model (CHM) was the auxiliary variable available for every population element. The small areas were 14 municipalities within a 2,184 km 2 study area for which an estimate of the mean forest biomass was sought. The municipalities were between 31 and 527 km 2 and contained 1-35 NNFI sample plots located within forest. The mean canopy height obtained from the CHM was found to have a strong linear correlation with forest biomass. Both the SRS estimator and the GREG estimator result in unstable estimates if they are based on too few observations. Although this is not the case for the EBLUP estimator, the estimators were only compared for municipalities with more than five sample plots. The SRS resulted in the highest standard errors in all municipalities. Whereas the GREG and EBLUP standard errors were similar for small areas with many sample plots, the EBLUP standard error was usually smaller than the GREG standard error. The difference between the EBLUP and GREG standard error increased with a decreasing number of sample plots within the small area. The EBLUP estimates of mean forest biomass within the municipalities ranged between 95.01 and 153.76 Mg ha -1, with standard errors between 8.20 and 12.84 Mg ha -1. © 2012 Springer-Verlag.
Strand G.-H.,Norwegian Forest And Landscape Institute
Environmental Modelling and Software | Year: 2011
A landscape region can be drawn on a map as a geographic feature with distinct boundaries. Reality is, however, that the change from one landscape to another usually is gradual and that landscapes therefore have uncertain or undetermined boundaries. A thematic map of landscape regions is therefore a too simple model of the landscape. An alternative approach is to consider landscape categories as purely theoretical concepts. With this perspective, a particular geographical location can be more or less affiliated with a number of different landscape categories. Such a conception of landscape does not lead to a traditional thematic map of uniform, non-overlapping regions, but to a landscape model composed of multiple overlapping probability surfaces. This article shows how such a landscape model can be established using binary logistic regression. The method is tested and the result is assessed against an existing landscape map of Norway much used in policy impact analysis in this country. The overall objective is to develop a data driven landscape model that can supplement, elucidate and for some purposes maybe even replace, the qualitative landscape description represented by the traditional landscape map. © 2011 Elsevier Ltd.
Lange H.,Norwegian Forest And Landscape Institute
International Journal of Bifurcation and Chaos | Year: 2011
In ecosystem research, data-driven approaches to modeling are of major importance. Models are more often than not shaped by the spatiotemporal structure of the observations: an inverse modeling approach prevails. Here, I investigate the insights obtained from Recurrence Quantification Analysis of observed ecosystem time series. As a typical example of available long-term monitoring data, I choose time series from hydrology and hydrochemistry. Besides providing insights into the nonstationary and nonlinear dynamics of these variables, RQA also enables a detailed and temporally local model-data comparison. © 2011 World Scientific Publishing Company.
Dramstad W.E.,Norwegian Forest And Landscape Institute |
Fjellstad W.J.,Norwegian Forest And Landscape Institute
Landscape Ecology | Year: 2013
For a quarter of a century, sustainable development has been on the political and research agendas. Within the field of landscape ecology, a wide array of research has documented the effects of alternative land uses, analysed driving forces of land use change and developed tools for measuring such changes, to mention but a few developments. There have also been great advances in technology and data management. Nevertheless, unsustainable land use continues to occur and the science of landscape ecology has had less influence on landscape change than aimed for. In this paper we use Norwegian examples to discuss some of the reasons for this. We examine mismatches in the spatial and temporal scales considered by scientists, decision-makers and those who carry out land use change, consider how this and other factors hinder effective communication between scientists and practitioners, and urge for a stronger focus on what it is that motivates people to action. We suggest that the concept of landscape services can be useful not only for researchers but also provide valuable communication and planning tools. Finally, we suggest more emphasis on applying adaptive management in landscape ecology to help close the gaps, both between researchers and policy and, even more crucially, between researchers and practitioners. © 2012 Springer Science+Business Media B.V.
Yakovlev I.A.,Norwegian Forest And Landscape Institute |
Fossdal C.G.,Norwegian Forest And Landscape Institute |
Johnsen O.,University of Life science
New Phytologist | Year: 2010
•Norway spruce expresses a temperature-dependent epigenetic memory from the time of embryo development, which thereafter influences the timing bud phenology. MicroRNAs (miRNAs)are endogenous small RNAs, exerting epigenetic gene regulatory impacts. We have tested for their presence and differential expression.•We prepared concatemerized small RNA libraries from seedlings of two full-sib families, originated from seeds developed in a cold and warm environment. One family expressed distinct epigenetic effects while the other not. We used available plant miRNA query sequences to search for conserved miRNAs and from the sequencing we found novel ones; the miRNAs were monitored using relative real time-PCR.•Sequencing identified 24 novel and four conserved miRNAs. Further screening of the conserved miRNAs confirmed the presence of 16 additional miRNAs. Most of the miRNAs were targeted to unknown genes. The expression of seven conserved and nine novel miRNAs showed significant differences in transcript levels in the full-sib family showing distinct epigenetic difference in bud set, but not in the nonresponding full-sib family. Putative miRNA targets were studied.•Norway spruce contains a set of conserved miRNAs as well as a large proportion of novel nonconserved miRNAs. The differentially expression of specific miRNAs indicate their putative participation in the epigenetic regulation. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).
Solberg S.,Norwegian Forest And Landscape Institute
International Journal of Remote Sensing | Year: 2010
Four alternative airborne laser scanning (ALS) canopy penetration variables were compared for their suitability for mapping of gap fraction, leaf area index and disturbances in a Scots pine forest. The variables were based on either echo counting or intensity, and on either first or first and last echoes. ALS data and field-measured gap fraction and effective leaf area index (LAIe) were gathered before and after a severe insect defoliation by pine sawflies. LAIe is a commonly used form of leaf area index that is mathematically derived from gap fraction, and includes the areas of foliage, branches and trunks, and which is not corrected for the clumping of foliage. The ALS penetration variables were almost equally strongly related to field-measured gap fraction and LAIe. The estimated slopes in the LAIe models varied from 0.94 to 2.71, and had coefficient of determination R2 values of 0.92-0.94. They were strongly correlated to each other (LAIe values of 0.95-0.98) and agreed fairly well for temporal changes of LAIe during the summer and the insect defoliation (R2 values of 0.82-0.95). Counting of first and last echoes produced penetration rates close to the gap fraction, and this penetration variable was able to penetrate tree crowns. Ground-only echoes represented mostly between-tree gaps, and canopy-first-ground-last pulses represented mostly within-canopy gaps. However, the penetration variables based on first and last echoes suffered from the problem that a second echo might be impaired both in low and in tall canopies. In low canopies, two adjacent echoes from the same pulse would be too close in time to be separated by the sensor, while in tall canopies the pulse might apparently be fragmented down through the canopy. The intensity-based penetration variables needed to be supplemented with reflectance values, or at least the ratio between reflectance of the canopy and the ground, and this ratio was estimated from the data. The study demonstrated that one might be able to distinguish between disturbance types, e.g. between defoliation and cutting, by comparing alternative ALS penetration variables. Insect defoliation was dominated by an increase in within-canopy gaps and, correspondingly, the fraction of partly penetrating canopy-first-ground-last pulses. Tree removals from cutting were dominated by increases in between-tree gaps and the corresponding fraction of ground-only pulses. © 2010 Taylor & Francis.