Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2013
Sammendrag
Bark beetles cause widespread damages in the coniferous-dominated forests of central Europe and North America. In the future, areas affected by bark beetles may further increase due to climate change. However, the early detection of the bark beetle green attack can guide management decisions to prevent larger damages. For this reason, a field-based bark beetle monitoring program is currently implemented in Germany. The combination of remote sensing and field data may help minimizing the reaction time and reducing costs of monitoring programs covering large forested areas. In this case study, RapidEye and TerraSAR-X data were analyzed separately and in combination to detect bark beetle green attack. The remote sensing data were acquired in May 2009 for a study site in south-west Germany. In order to distinguish healthy areas and areas affected by bark beetle green attack, three statistical approaches were compared: generalized linear models (GLM), maximum entropy (ME) and random forest (RF). The spatial scale (minimum mapping unit) was 78.5 m2. TerraSAR-X data resulted in fair classification accuracy with a cross-validated Cohen’s Kappa Coefficient (kappa) of 0.23. RapidEye data resulted in moderate classification accuracy with a kappa of 0.51. The highest classification accuracy was obtained by combining the TerraSAR-X and RapidEye data, resulting in a kappa of 0.74. The accuracy of ME models was considerably higher than the accuracy of GLM and RF models.
Forfattere
Randi Seljåsen Kjell gjermund Vogt Elisabeth Olsen Per Lea Lars Arne Høgetveit Torgeir Taje Richard Meadow Gunnar BengtssonSammendrag
submittedVersion
Forfattere
Simon Ballance Stefan Sahlstrøm Per Lea Nina Elisabeth Nagy Petter V. Andersen Tzvetelin Dessev Sarah Hull Maria Vardakou Richard FaulksSammendrag
This is a post-peer-review, pre-copyedit version of an article published in [European Journal of Nutrition]. The final authenticated version is available online at: https://doi.org/10.1007/s00394-012-0386-5
Forfattere
Lampros LamprinakisSammendrag
Valio, a well-established "national institution" in Finland, had a rich background based on cooperative tradition and extensive regional spread. In the late 1980s and early 1990s, the company had to undergo a process of change and re-organization in order to address the challenges arising from the EU accession. After years of restructuring and changing in its business model, Valio remains a major player in Finland and one of the most well-known brands in the region. The purpose of this case study is to stimulate a critical evaluation of the processes Valio undertook in order to address the coming challenges. The case is especially suited as a starting point for a broader discussion on organizational change and adaptation. Teaching notes are provided with proposals and questions.
Forfattere
Bjørn Arild Hatteland Steffen Roth Arild Andersen Kristin Kaasa Bente Støa Torstein SolhøySammendrag
Det er ikke registrert sammendrag
Forfattere
M Ashraful Islam Henrik Lütken Sissel Haugslien Dag-Ragnar Blystad Sissel Torre Jakub Rolcik Søren Rasmussen Jorunn Elisabeth Olsen Jihong Liu ClarkeSammendrag
Euphorbia pulcherrima, poinsettia, is a non-food and non-feed vegetatively propagated ornamental plant. Appropriate plant height is one of the most important traits in poinsettia production and is commonly achieved by application of chemical growth retardants. To produce compact poinsettia plants with desirable height and reduce the utilization of growth retardants, the Arabidopsis SHORT INTERNODE (AtSHI) gene controlled by the cauliflower mosaic virus 35S promoter was introduced into poinsettia by Agrobacterium-mediated transformation. Three independent transgenic lines were produced and stable integration of transgene was verified by PCR and Southern blot analysis. Reduced plant height (21–52%) and internode lengths (31–49%) were obtained in the transgenic lines compared to control plants. This correlates positively with the AtSHI transcript levels, with the highest levels in the most dwarfed transgenic line (TL1). The indole-3-acetic acid (IAA) content appeared lower (11–31% reduction) in the transgenic lines compared to the wild type (WT) controls, with the lowest level (31% reduction) in TL1. Total internode numbers, bract numbers and bract area were significantly reduced in all transgenic lines in comparison with the WT controls. Only TL1 showed significantly lower plant diameter, total leaf area and total dry weight, whereas none of the AtSHI expressing lines showed altered timing of flower initiation, cyathia abscission or bract necrosis. This study demonstrated that introduction of the AtSHI gene into poinsettia by genetic engineering can be an effective approach in controlling plant height without negatively affecting flowering time. This can help to reduce or avoid the use of toxic growth retardants of environmental and human health concern. This is the first report that AtSHI gene was overexpressed in poinsettia and transgenic poinsettia plants with compact growth were produced.
Forfattere
Jane Uhd Jepsen Erik Martin Biuw Rolf Anker Ims Lauri Teemu Kapari Tino Schott Ole Petter Laksforsmo Vindstad Snorre HagenSammendrag
Insect outbreaks in northern-boreal forests are expected to intensify owing to climate warming, but our understanding of direct and cascading impacts of insect outbreaks on forest ecosystem functioning is deficient. The duration and severity of outbreaks by geometrid moths in northern Fennoscandian mountain birch forests have been shown to be accentuated by a recent climatemediated range expansion, in particular of winter moth (Operophtera brumata). Here, we assess the effect of moth outbreak severity, quantified from satellite-based defoliation maps, on the state of understory vegetation and the abundance of key vertebrate herbivores in mountain birch forest in northern Norway. We show that the most recent moth outbreak caused a regional-scale state change to the understory vegetation, mainly due to a shift in dominance from the allelopathic and unpalatable dwarf-shrub Empetrum nigrum to the productive and palatable grass Avenella flexuosa. Both these central understory plant species responded significantly and nonlinearly to increasing outbreak severity. We further provide evidence that the effects of the outbreak on understory vegetation cascaded to cause strong but opposite impacts on the abundance of the two most common herbivore groups. Rodents increased with defoliation, largely mirroring the increase in A. flexuosa, whereas ungulate abundance instead showed a decreasing trend. Our analyses also suggest that the response of understory vegetation to defoliation may depend on the initial state of the forest, with poorer forest types potentially allowing stronger responses to defoliation
Forfattere
Christian Guido Bruckner Kerstin Mammitzsch Günter Jost Juliane Wendt Matthias Labrenz Klaus JürgensSammendrag
Pelagic marine oxygen-depleted zones often exhibit a redox gradient, caused by oxygen depletion due to biological demand exceeding ventilation, and the accumulation of reduced chemical species, such as hydrogen sulfide. These redox gradients harbour a distinct assemblage of epsilonproteobacteria capable of fixing carbon dioxide autotrophically in the dark and potentially of utilizing hydrogen sulfide chemolithotrophically by oxidation with nitrate. Together, these two processes are referred to as chemolithoautotrophic denitrification. The focus of this study was the recently isolated and cultivated representative strain of pelagic epsilonproteobacteria, 'Sulfurimonas gotlandica' strain GD1, specifically dark carbon dioxide fixation and its substrate turnovers during chemolithotrophic denitrification. By connecting these processes stoichiometrically and comparing the results with those obtained for dark carbon dioxide fixation and nutrient concentrations measured in pelagic redox gradients of the Baltic Sea, we were able to estimate the role of chemolithoautotrophic denitrification in the environment. Evidence is provided for a defined zone where chemolithoautotrophic denitrification of these epsilonproteobacteria allows the complete removal of nitrate and hydrogen sulfide from the water column. This water layer is roughly equivalent in thickness to the average overlapping region of the two substrates, but slightly larger. Such a difference may be explained by a variety of reasons, including, e.g. utilization of substrates present at concentrations below the detection limit, alternative usage of other substrates as thiosulfate or nitrous oxide, or comparable activities of other microbes. However, the combined results of in vitro and in situ studies strongly suggest that epsilonproteobacteria are primarily responsible for hydrogen sulfide and nitrate removal from pelagic Baltic Sea redox gradients.
Forfattere
William White Anders Lunnan Erlend Nybakk Biljana KulisicSammendrag
The renewable energy sector (RES) often receives financial, institutional or educational support from the government. A significant challenge for the actors in the RES field is policy consistency. When investments are carried out, a prognosis for future policies must be made. If the future is uncertain, larger risk margins should be included in the investment appraisals. Sudden, unexpected policy changes are one type of uncertainty that makes it more difficult to attract capital. In this article, we discuss the consequences of discontinuities in policy support using a case study approach. In Ontario, feed-in tariffs were introduced in 2009 and resulted in a large uptake in the programme. In 2010, the subsidies were drastically cut, resulting in the RES community losing confidence that the government would offer consistent support to the sector. In Norway, a large new biodiesel plant was opened by the Minister of the Environment only a few weeks before the government announced a major change in the bioenergy policy. As a result, the new plant was closed and restructured, and the investors lost nearly all of their investments. The government lost political credibility, making it difficult to raise private capital for new investments in this sector in Norway. We do not argue that policies should not be changed, but the manner in which policies are changed plays an important role. Our study shows that large, unexpected changes in policies increase uncertainty and may have a negative impact on investments. This topic should be further researched.
Sammendrag
Det er ikke registrert sammendrag