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.
2024
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Maria Wilhelmina Tuomi Tove Hilde Ågnes Utsi Nigel Gilles Yoccoz Claire W. Armstrong Victoria Gonzalez Snorre Hagen Inga-Svala Jonsdottir Francisco I. Pugnaire Katriona Shea David A. Wardle Sophia Theresa Zielosko Kari Anne BraathenSammendrag
Ongoing Arctic greening can increase productivity and reindeer pasture quality in the tundra. However, greening may also entail proliferation of unpalatable species, with consequences for pastoral social-ecological systems. Here we show extensive greening across 20 reindeer districts in Norway between 2003 and 2020, which has reduced pasture diversity. The allelopathic, evergreen dwarf-shrub crowberry increased its biomass by 60%, with smaller increases of deciduous shrubs and no increase in forbs and graminoids, the most species rich growth forms. There was no evidence for higher reindeer densities promoting crowberry. The current management decision-making process aims at sustainable pasture management but does not explicitly account for pasture changes and reduced diversity. Large-scale shifts towards evergreening and increased allelopathy may thus undermine the resource base for this key Arctic herbivore and the pastoral social-ecological system. Management that is sensitive to changes in pasture diversity could avoid mismanagement of a social-ecological system in transition.
Forfattere
Mekjell MelandSammendrag
Det er ikke registrert sammendrag
Forfattere
Knut ØistadSammendrag
Det er ikke registrert sammendrag
Forfattere
Annika M. Felton Adam Felton Per-Ola Hedwall David Raubenheimer Stephen Simpson Robert Spitzer Hilde Karine WamSammendrag
The moose (Alces alces) is a large-bodied, ruminant herbivore inhabiting temperate and boreal forests, where their foraging can profoundly influence ecological processes. In intensively managed landscapes, such as large parts of Scandinavia, browsing by moose can also affect human economic interests, such as commercial forestry. Deciphering the nutritional underpinnings of the moose’ foraging choices is therefore in the interest of both wildlife ecology and forest management. In this talk I will summarise findings from several studies from Scandinavia in which we have used the nutritional geometry framework to study moose foraging behavior. First, a small feeding experiment with captive moose indicated that their food choice was not governed by energy maximization as previously postulated. Instead the moose appeared to combine food to reach a target macronutritional balance. We later confirmed this pattern of macronutrient balancing by analysing rumen content (by wet chemistry and NIRS) and faeces (indirectly via by DNA metabarcoding) from a large number of wild moose during wintertime across Sweden. The moose’ tendency to maintain a stable balance between protein and non-structural carbohydrates was most recently confirmed by a detailed study of moose summer time in Norway, using camera collars and plant collections. These studies on the Scandinavian moose have also revealed patterns of complementarity, compensatory intake, linkages to damage and fitness, and valuable information about key forage plant species, and thereby help to improve our understanding of nutritional ecology.
Sammendrag
Potential climate change impacts on water resources have been extensively assessed in Norway due to substantial changes in climate in the recent decades. However, the combined and isolated effects of forest and forest management have been rarely considered in the climate impact studies in Norway although about 38% of the land area is covered by forest. This study aims to improve hydrological impact projections in forest dominant catchments by considering the effects of forest growth and management and to attribute hydrological changes to climate and forest changes. The eco-hydrological model SWIM (Soil and Water Integrated Model) was applied to simulate hydrological processes and extremes for two micro-scale, two meso-scale and two macro-scale catchments, accounting for the effects of spatial scale. The climate projections were generated by three EURO-CORDEX (Coordinated Downscaling Experiment for the European domain) regional climate models (RCMs) for two RCPs (Representative Concentration Pathways, RCP2.6 and RCP4.5) and were bias corrected using the quantile-mapping method. Forest development over time was simulated as a function of climate determining growth and SSP-dependent harvest levels determining wood outtake. The simulations were initialized with the forest status of the year 2020 and different forest types are distinguished according to structural characteristics represented by three key parameters: leaf area index, mean tree height and surface albedo. Preliminary simulation results show that there are minor changes (within ±5%) in hydrological processes under the combinations of the climate and forest scenarios for these catchments. Climate change is the major driver of hydrological change at the catchment scale whereas forest development mainly influences the spatial distribution of the hydrological fluxes. The results further indicate that forest growth under a warming climate helps to reduce the risk of the floods and drought slightly by reducing surface runoff in wet periods and increasing base flow in dry periods, respectively.
Sammendrag
Agricultural sustainability is threatened by both water deficit and water excess, especially at the presence of extreme meteorological events resulting from climate change. However, there has been lack of demonstrations on management options with long-term values for agricultural adaptation to runoff. Using 20 years of monitoring data (1993–2012) for two experimental fields in the Canadian Prairies as a case study, we quantified the effects of rainfall characteristics, crop type and biomass, and tillage on growing-season runoff generation using regression analyses and thereafter scenario comparisons. With growing-season gross rainfall ranging between 183 and 456 mm, runoff responses varied between 0 and 59 mm. Over the 20-year study period, 70%–74 % of the growing season runoff was generated by rainfall events >100 mm. Compared to high-intensity tillage, long-term conservation tillage reduced both overall runoff and runoff in large events likely by improving water infiltration. Under both tillage methods, growing-season runoff significantly increased with increasing rainfall but decreased with increasing biomass (R2 range: 0.40–0.58; p range: 0.0007–0.02). At the event level, the rainfall-runoff relationship followed a piecewise regression model (Cd ¼ 0.82; p
Forfattere
Alexander Hammel Lia-Maria Cucos Iuliana Caras Irina Ionescu Catalin Tucureanu Vlad Tofan Adriana Costache Adrian Onu Lara Hoepfner Michael Hippler Juliane Neupert Costin-Ioan Popescu Crina Stavaru Norica Branza-Nichita Ralph BockSammendrag
Microalgae are promising production platforms for the cost-effective production of recombinant proteins. We have recently established that the red alga Porphyridium purpureum provides superior transgene expression properties, due to the episomal maintenance of transformation vectors as multicopy plasmids in the nucleus. Here, we have explored the potential of Porphyridium to synthesize complex pharmaceutical proteins to high levels. Testing expression constructs for a candidate subunit vaccine against the hepatitis C virus (HCV), we show that the soluble HCV E2 glycoprotein can be produced in transgenic algal cultures to high levels. The antigen undergoes faithful posttranslational modification by N-glycosylation and is recognized by conformationally selective antibodies, suggesting that it adopts a proper antigenic conformation in the endoplasmic reticulum of red algal cells. We also report the experimental determination of the structure of the N-glycan moiety that is attached to glycosylated proteins in Porphyridium. Finally, we demonstrate the immunogenicity of the HCV antigen produced in red algae when administered by injection as pure protein or by feeding of algal biomass.
Sammendrag
There is currently no quality sorting of harvested hardwood timber in Norway on a national scale. Medium- and high-quality logs including those from birch (Betula pubescens Ehrh., B. pendula Roth) are thus not utilized according to their potential monetary value. Increased domestic utilization of quality birch timber requires that the quality of harvested logs be properly assessed for potential end uses. A preferred sorting procedure would use visually detectable external log defects to grade roundwood timber. Knots are an important feature of inner log quality. Thus, the aim of this study was to evaluate whether correlations between branch scar size and knot features could be found in Norwegian birch. Using 168 knots from seven unpruned birch trees, external bark attributes often showed strong correlations with internal wood quality. Both length of the mustache and length of the seal performed well as predictors of stem radius at the time of knot occlusion. The presence of a broken off branch stub as part of an occluded knot significantly increased the knot-effected stem radius, proving that the practice of removing branches and branch stubs along the lower trunk is a crucial measure if quality timber production is the primary management goal.
Forfattere
Ari Hietala Wilson Lara Henao André Kolsgaard Simon Seljegard Nina Elisabeth Nagy Isabella Børja Tor Arne Justad Yngve Rekdal Even Bergseng Halvor SolheimSammendrag
Forest grazing by free-roaming livestock is a common practice in many countries. The forestry sector sees the practice as unfortunate owing to several reasons, such as damages inflicted by grazing in young plantations. Concerning Norway spruce forests, a tree species known to develop wood decay with high frequency followed from stem bark damage, there is a strong perception among foresters that the trampling damage caused by livestock on the superficial root system of this tree leads to decay. Because of the very limited scientific documentation available on this topic, we pursued a clarification by investigating three 38- to 56-year-old Norway spruce forests used for silvopasture. Two types of injuries were observed on exposed roots: bark cracks characterized by resin exudation, and injuries involving localized bark peeling and exposure of the underlying wood. These injuries occurred up to 250 cm away from the root collar, with the sector 50–150 cm away from the root collar showing the highest incidence of injuries. In two of the forest stands, wood within the injured root areas was primarily colonized by the wound parasite Corinectria fuckeliana or species of the order Helotiales, fungi that do not cause wood decay. Wood colonization of injured roots by Heterobasidion species, the most frequent wood decay fungi of Norway spruce, was common in the third stand, but only in a few cases it was possible to deduce that the colonization had probably initiated via trampling injuries on roots. In a few cases, an injury was located at stem base at the root collar height along paths used by animals, and in such cases, it was obvious that stem colonization by Heterobasidion species had initiated via the wound. The relatively small amount of data warrants caution when drawing conclusions. Considering the high establishment frequency of decay via stem bark wounds of Norway spruce observed in previous studies, our data would suggest that roots are generally better equipped to defend themselves upon infliction of superficial wounds than stem of this tree species. The likelihood of trampling injuries leading to decay may vary considerably between different stands, this presumably depending on the level of local propagule pressure by pathogenic wood decay fungi and the frequency of damages close to root collar.