D'alba L.,Ghent University |
Carlsen T.H.,NIBIO |
Asgeirsson A.,University of Iceland |
Shawkey M.D.,Ghent University |
Jonsson J.E.,University of Iceland
Journal of Avian Biology | Year: 2017
Insulation is an essential component of nest structure that helps provide incubation requirements for birds. Many species of waterfowl breed in high latitudes where rapid heat loss can necessitate a high energetic input from parents and use down feathers to line their nests. Common eider Somateria mollissima nest down has exceptional insulating properties but the microstructural mechanisms behind the feather properties have not been thoroughly examined. Here, we hypothesized that insulating properties of nest down are correlated to down feather (plumule) microstructure. We tested the thermal efficiency (fill power) and cohesion of plumules from nests of two Icelandic colonies of wild common eiders and compared them to properties of plumules of wild greylag goose Anser anser. We then used electron microscopy to examine the morphological basis of feather insulating properties. We found that greylag goose down has higher fill power (i.e. traps more air) but much lower cohesion (i.e. less prone to stick together) compared to common eider down. These differences were related to interspecific variation in feather microstructure. Down cohesion increased with the number of barbule microstructures (prongs) that create strong points of contact among feathers. Eider down feathers also had longer barbules than greylag goose down feathers, likely increasing their air-trapping capacity. Feather properties of these two species might reflect the demands of their contrasting evolutionary history. In greylag goose, a temperate, terrestrial species, plumule microstructure may optimize heat trapping. In common eiders, a diving duck that nests in arctic and subarctic waters, plumule structure may have evolved to maximize cohesion over thermal insulation, which would both reduce buoyancy during their foraging dives and enable nest down to withstand strong arctic winds. © 2017 Nordic Society Oikos.
News Article | March 1, 2017
Until the modern era, the human mark on the northernmost forests of North America, Europe, and Asia was light. Human populations in these challenging environments were too small to make a big impact through agriculture or timber harvests. But increasing evidence indicates people influenced the northern forests indirectly, by igniting or suppressing fires. Distinguishing human from climatic influence on historical fire patterns is critical to forest management planning, which is guided by historical patterns of fire frequency, size, and intensity. A boreal forest nature reserve in southern Norway offered a unique opportunity to reconstruct past events, as scientists from the Norwegian Institute of Bioeconomy Research (NIBIO) demonstrated in a report published online ahead of print in the Ecological Society of America's journal Ecological Monographs. The trees told a story of a surge in human-instigated fires during the 17th and 18th centuries, followed by fire suppression after AD 1800, as economic motivations changed. Unlike the boreal forests of North America, which more frequently experience fires hot enough to kill most trees, the forests of Norway, Sweden, and Finland characteristically burn at low to medium intensity. Fires burn through the understory, leaving mature trees scarred, but living. The burn scars, combined with tree ring data, and historical documents, present a record of wildfire behavior in the second millennium. Together with former PhD-student Ylva-li Blanck of the Norwegian University of Life Science, researchers Jørund Rolstad and Ken Olaf Storaunet collected and analyzed 459 wood samples from old, fire-damaged pine tree stumps, snags, downed logs and living trees in 74 square kilometers (28 square miles) study area in Trillemarka-Rollagsfjell nature reserve. At 60 degrees North, Trillemarka-Rollagsfjell shares a latitude close to Anchorage, Alaska and Whitehorse, the capital of Canada's Yukon province. The pine and spruce dominated forest ecosystem has many traits in common with the forested ecosystems of interior Alaska and Canada. The collected samples were cross-dated by dendrochronology, a method used to date wooden samples by comparing tree rings with a known time-sequence from many other collected and dated tree ring series. In this way, scientists can determine the date and location of forest fires with great accuracy. Based on where in the tree ring the damage occurred, the forest researchers can also say at what time of the year it burned. From this record, the authors estimated fire location, frequency, size, and seasonality over the last 700 years, comparing the fire history to historical records from the National Archives of Norway, including juridical documents, diplomas, and old maps of the area and old agricultural textbooks and reports. They dated 254 individual fires from AD 1257-2009. The oldest living tree they sampled dated to AD 1515 and the oldest stump to AD 1070. From AD 1300 to 1600, wildfires ignited during late summer, with about 5-10 ignitions per quarter century, generally occurring during warm, dry summers. In the next two centuries, fire frequency rose dramatically, particularly in the mid-17th century. Early summer fires grew in prevalence. Books and other documents from this time period record a rising use of slash-and-burn cultivation and rangeland burning, explained author Ken Olaf Storaunet. The population was recovering from the devastation of the Black Death and several subsequent epidemics. People returned to abandoned lands and began using fire to improve land for grazing animals and to cultivate crops. The average length of time between recurrences of fire in the same location fell by half, from 73 to 37 years. Increasing demand for timber in Europe raised the value of forests and discouraged slash-and-burn cultivation practices. The fires legislation banning the use of fire in Norway came in 1683. After AD 1800, fire frequency and size dropped precipitously, with only 19 fires occurring in the study area during the last 200 years. Ecologically, the period from 1625 and onwards to today is probably unique, and something that perhaps has not happened in thousands of years, Storaunet said. Studies in Alaska and Canada have projected that hotter, drier summers may increase annual wildfire burn areas by two to three times by the end of the century. In Norway, the North Atlantic Ocean may temper hotter summers with more precipitation. Forest fires can be catastrophic and damaging for both home owners and the forest industry. In Canada each year, on average, 8,600 fires burn 25,000 square kilometers (10,000 square miles) of forest. But forest fires play an important part in the ecology of northern forests. Natural forests are not a continuous expanse of old trees. Forest fires create a mosaic of burnt and unburnt areas, shaping the species composition and the age distribution of the forest. Fires open up the tree canopy, letting light in, releasing nutrients to the understory, and aiding regrowth. Charcoal changes soil structure, and charred tree trunks become habitats of great importance for the biological diversity of the forest--both above and below ground. Many rare species, especially fungi and insects, depend on the variation forest fires create. Many of today's forest reserves have perhaps never been as unnatural as they are today, Storaunet pointed out. The historical studies in Trillemarka-Rollagsfjell nature reserve show that fire has been a natural, and very dynamic, part of the forest ecosystem throughout history. And this ecosystem is affected by climate, vegetation and not least the way humans use forest, Storaunet said. Rolstad, J., Blanck, Y. and Storaunet, K. O. (2017), Fire history in a western Fennoscandian boreal forest as influenced by human land use and climate. Ecological Monographs (early view) doi:10.1002/ecm.1244. Open Access. The Ecological Society of America, founded in 1915, is the world's largest community of professional ecologists and a trusted source of ecological knowledge, committed to advancing the understanding of life on Earth. The 10,000 member Society publishes five journals and a membership bulletin and broadly shares ecological information through policy, media outreach, and education initiatives. The Society's Annual Meeting attracts 4,000 attendees and features the most recent advances in ecological science. Visit the ESA website at http://www. .
Nestby R.,NIBIO |
Journal of Berry Research | Year: 2017
BACKGROUND: It is questioned if Norwegian nurseries can compete with the continental nursery industry in an open market. OBJECTIVE: Investigated how quality of certified Norwegian strawberry transplants, developed and yielded from planting to first cropping year. METHODS: Plant qualities of Norwegian fresh and cold stored bare root-A nd plug-plants of eKoronaf and eSonataf were examined for establishing and yield parameters in the open, after three intervals of planting. Fresh plug-plants were delivered when available. Trials were established at NIBIO Research Station Kvithamar, Norway. Growth and yield parameters were registered in the establishing and cropping years. RESULTS: Plant establishment was poor in 2013 compared with 2014. Bare-root plants stored at 2.4.C generally developed poorly. Plug-plants established well at all delivery dates, except fresh plug in one year.Development of runner plants depended on plant type, cultivar and year. Plug-A nd bare root-plants planted immediately after first delivery generally developed best crowns. Primary flower primordia reached a more developed stage for eSonataf than for eKoronaf. Fruit yield of bare root was low in the establishing years. Plant-types differed in yield and fruit weight between cropping years. CONCLUSIONS:Bare-root and plug-plants planted one day after delivery generally yielded best. Storage of bare-root plants generally reduced yield. Fresh plug plants had low yield when planted late. Fruit yield of A15 and A13 in the establishing year was not satisfactory. © 2017-IOS Press and the author.
Spatial Statistics | Year: 2017
An undesirable property of systematic spatial sampling is that there is no known method allowing unbiased estimation of the uncertainty of statistical estimates from these surveys. A number of alternative variance estimation methods have been tested and reported by various authors. Studies comparing these estimators are inconclusive, partly because the studies compare different sets of estimators. In this paper, three estimators recommended in recent studies are compared using a single test dataset with known properties. The first estimator compared in this study (ST4) is based on post-stratification of the data. The second estimator (V08) is using a predetermined correction factor calculated from the spatial autocorrelation. The third estimator (MB) is a model based prediction calculated using values from the semivariogram. MB and ST4 were both found to be fairly accurate, while V08 consistently underestimated the variance in this study. V08 relies on the assumption that the autocorrelation structure in the dataset can be described using a particular exponential function. The most likely explanation of the weak result for V08 is that this assumption is violated by the empirical data used in the experiment. A better correction factor can be calculated, but the safe approach is to use MB or ST4. © 2017 The Author
Candelier K.,CIRAD - Agricultural Research for Development |
Dibdiakova J.,NIBIO |
Volle G.,CIRAD - Agricultural Research for Development |
Rousset P.,CIRAD - Agricultural Research for Development |
Rousset P.,King Mongkut's University of Technology Thonburi
Thermochimica Acta | Year: 2016
Heat treatment helps enhance some properties of raw biomass by improving its decay resistance, its dimensional stability, increasing energy density and reducing transport costs of biomass. During storage period, many industrial sites undergo fires caused by self-ignition of torrefied or carbonized biomass. The main objective of this work was to study the chemical behavior of heat treated wood under oxygen exposure. Softwood and hardwood species have been thermally treated under a nitrogen atmosphere at different treatment conditions intensities. Sample mass and heat flow have been measured during the process to observe the temperature, time and air flow influence on reaction mechanisms of heat treated wood. The oxidation process and heat flux have been evaluated in addition. Results showed that reaction heat flows used for the treatment were correlated with temperature and time of thermal degradation of both examined wood species, as well as wood mass loss, respectively. However, hardwood (beech) seems to be more sensitive to thermal degradation and oxidation than softwood (silver fir) species. In addition, differential scanning calorimetry exothermic peak and wood mass gain were observed during oxygen exposure. In fact, this phenomenon was more pronounced for degradation carried out at high temperatures and times and it tends to be correlated with the elemental composition of wood. The main evolved products of heat treated wood were identified as water (H2O), carbon monoxide (CO) and carbon dioxide (CO2). © 2016 Elsevier B.V.
Shimozawa N.,Japan National Institute of Biomedical Innovation |
Nakamura S.,Shiga University of Medical Science |
Takahashi I.,NIBIO |
Hatori M.,Japan National Institute of Biomedical Innovation |
And 2 more authors.
Reproduction | Year: 2010
Several cell types from the African green monkey (Cercopithecus aethiops), such as red blood cells, primary culture cells from kidney, and the Vero cell line, are valuable sources for biomedical research and testing. Embryonic stem (ES) cells that are established from blastocysts have pluripotency to differentiate into these and other types of cells. We examined an in vitro culture system of zygotes produced by ICSI in African green monkeys and attempted to establish ES cells. Culturing with and without a mouse embryonic fibroblast (MEF) cell monolayer resulted in the development of ICSI-derived zygotes to the blastocyst stage, while culturing with a buffalo rat liver cell monolayer yielded no development (3/14, 21.4% and 6/31, 19.4% vs 0/23, 0% respectively; P<0.05). One of the nine blastocysts, which had been one of the zygotes co-cultured with MEF cells, formed flat colonies consisting of cells with large nuclei, similar to other primate ES cell lines. The African green monkey ES (AgMES) cells expressed pluripotency markers, formed teratomas consisting of three embryonic germ layer tissues, and had a normal chromosome number. Furthermore, expression of the germ cell markers CD9 and DPPA3 (STELLA) was detected in the embryoid bodies, suggesting that AgMES cells might have the potential ability to differentiate into germ cells. The results suggested that MEF cells greatly affected the quality of the inner cell mass of the blastocysts. In addition, AgMES cells would be a precious resource for biomedical research such as other primate ES cell lines. © 2010 Society for Reproduction and Fertility.
Dees M.W.,NIBIO |
Lysoe E.,NIBIO |
Alsheikh M.,Norwegian University of Life Sciences |
Davik J.,NIBIO |
Molecular Plant Pathology | Year: 2015
Summary: Common scab, caused by species from the bacterial genus Streptomyces, is an important disease of potato (Solanum tuberosum) crops worldwide. Early tuberization is a critical period for pathogen infection; hence, studies of host gene expression responses during this developmental stage can be important to expand our understanding of the infection process and to identify putative resistance genes. In an infection experiment with the highly susceptible potato cultivar Saturna and the relatively resistant cultivar Beate, transcription profiles were obtained by RNA sequencing at two developmental stages: the early hook stage and the early tuber formation stage. Our results indicate that 'Beate' mounts an early and sustained response to infection by S.turgidiscabies, whereas the defence response by 'Saturna' ceases before the early tuber formation stage. Most pronounced were the putative candidate defence-associated genes uniquely expressed in 'Beate'. We observed an increase in alternative splicing on pathogen infection at the early hook stage for both cultivars. A significant down-regulation of genes involved in the highly energy-demanding process of ribosome biogenesis was observed for the infected 'Beate' plants at the early hook stage, which may indicate an allocation of resources that favours the expression of defence-related genes. Molecular Plant Pathology © 2015 BSPP and John Wiley & Sons Ltd.
News Article | November 23, 2015
According to the OECD, bioeconomics will represent the guiding principle of the European economy by 2055. This means that focus will be centred on the production and transformation of renewable biological resources from the agricultural, forestry and marine aquaculture sectors, and biomass will represent the major source of raw materials. If the experts are to be believed, we are in many ways on the brink of a new industrial revolution. The Norwegian government is currently developing a national strategy in this field, and researchers will now be carrying out fundamental analytical work aimed at promoting a higher level of sustainable innovation in Norway. "As part of the Biosmart project we'll be carrying out a futures analysis to identify stakeholders and others that will play a part in a bioeconomy, and to find out where the various resources will be found", says Magnar Forbord at the Norwegian Centre for Rural Research (NCRR). "If such ideas are to be profitable, we'll have to start thinking in terms of coordination and industrial clusters", adds Vibeke Stærkebye Nørstebø at SINTEF. "An incredible amount of marine and land-based resources currently remain unexploited because no-one is facilitating their development", she says. The idea of using resources derived from nature is nothing new to Norwegians, who have always exploited their natural resources. And this is set to continue. Exploitation will be smarter, and value will be added by means of refining processes and innovative applications. For example, the company Borregaard manufactured paper and paper products from timber for many years. In the course of a 20-year period, the company has succeeded in developing a range of high-value products from tree components that were previously regarded as waste. These products are currently making a significant contribution to the company's revenues. Another example is the company Biokraft Skogn, which was established in connection with Norske Skog's paper factory. The company manufactures liquid biogas from biological waste derived from the fish farming and forestry sectors. Among other things, the gas is used as fuel for public transport buses in Trondheim. "These examples could be among the first of many", says Forbord. "Biomass is made up of trees, grass and different varieties of seaweed, as well as foodstuffs such as fish, maize, meat and milk. What we currently regard as unwanted remains and waste can be transformed into new products which will subsequently contribute towards a new, biologically-based, industrial sector. Over the three-year project period, researchers from the NCRR, SINTEF, NIBIO, NTNU and Norut, as well as a number of international research institutes, will be working with a total of eleven topics or so-called 'work packages'. Furthermore, a series of scientific studies will be carried out looking into issues such as biotechnological transitions, legal rights, and the levels and scope at which wealth generation can be anticipated. The researchers are now starting a survey of 1500 companies in the agricultural, forestry, fisheries, industrial and bioscience sectors to find out what they envisage for themselves in the future. What do they currently us resources for, and what are their views on opportunities for change? When all the data have been collected, the researchers will hopefully have acquired a picture of where resources such as forests, maize and fisheries products are produced, where the people with the know-how are located, and what kind of products it might be possible to develop. With this as a springboard, it will be possible to develop projects and manufacturing processes that bring together economics, resource exploitation, levels of expertise and acceptance within the community as an integrated whole. "All bio-resources will be mapped and set in the context of the local population, transport networks, existing industries and suchlike", says Nørstebø. "This will provide a basis for identifying where it may be feasible to locate the industrial clusters", she says. "We'll need different sectors to work together, and this means breaking down the current barriers between the agricultural, forestry and aquaculture sectors. There are many questions", she says. "For example, where will the industries establish themselves, and what products should they focus on? What resources will supply the input and what will the products be? For example, will waste products be used at locations other than those at which they are produced? Where can we establish an integrated industrial cluster, and which companies should participate?" says Nørstebø. One of the work packages will address the issues of innovation, regulatory frameworks, and the policies the public authorities should adopt in terms of resource allocation and regulations. Another project will be a comparative study involving Norway, New Zealand and Germany. "This will be carried out in order to understand how societies change at national level", explains Forbord. "It's vital to look into what factors may act as incentives for change towards a bioeconomy," he says.