Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2026
Authors
Anne Helena Kettunen Ellen L. F. White Mervi Honkatukia Nina Svartedal Anette Kristine Krogenæs Jaana Peippo Amin SayyariAbstract
The conservation of local poultry genetic resources requires complementary ex situ strategies, particularly when live populations are maintained at a single location. Previous gene bank insemination trials with frozen–thawed semen from Norwegian conserved lines showed acceptable subjective post-thaw motility but unexpectedly low fertilization success, highlighting the need for objective quality-control assessment. The aim of this study was to establish an objective cryobank quality-control baseline for frozen–thawed semen from two Norwegian conserved rooster lines. Specifically, the study evaluated whether routinely applied objective semen-quality assessment methods, including computer-assisted semen analysis (CASA) and flow-cytometric viability assessment, could detect differences between rooster lines and post-thaw handling conditions. Cryopreserved semen doses collected in 2018 and stored in the Norwegian poultry gene bank were thawed and evaluated from 24 roosters representing the Jærhøns and NorBrid8 lines. The samples were originally collected as part of the routine cryopreservation activities of the Norwegian poultry gene bank and therefore did not require specific approval from the Norwegian Food Safety Authority (Mattilsynet). Post-thaw semen quality was assessed using CASA and flow-cytometric viability analysis. The effects of line and short-term refrigerated holding were evaluated using mixed-effects models, supported by minimum detectable effect calculations, correlation analysis, and principal component analysis. Short-term post-thaw refrigerated holding reduced several CASA-derived motility and velocity traits, while viability assessment provided complementary information on membrane integrity. Line-associated differences in selected motility traits and substantial rooster-to-rooster variability in all traits were observed. Multivariate analyses identified major dimensions of covariance among sperm-quality traits without implying direct biological mechanisms of fertility failure. CASA and flow-cytometric viability assessment can provide an objective baseline for cryobank quality control of frozen–thawed rooster semen. However, fertility trials and molecular sperm-integrity markers are required to determine the biological causes of the previously observed discrepancy between motility and fertility.
Authors
Anders BrynAbstract
Fjellviten: overvåking av klima og natur i høgfjellet
Authors
Nina SvartedalAbstract
No abstract has been registered
Abstract
Errors in thematically detailed land-cover maps have large consequences for downstream applications. Moreover, simulation-based studies suggest that land-cover classifiers are sensitive to errors in reference data. We (1) quantified the expected error from field interpretation of land-cover types; (2) the sensitivity of classifiers to reference data errors; and (3) the error transferred from reference data to classifiers. Lastly, we (4) recommended strategies to reduce errors. The study area was mapped by 12 field interpreters divided into three equal-sized experience-level groups. The field-based land-cover maps were aggregated to three thematic resolutions and used to train 6804 land-cover classifiers by varying inputs, algorithm, and hyperparameter values. Separately from the first field campaign, four field interpreters classified validation data points, which were used to quantify error for each field interpreter and land-cover classifier, as the proportion of incorrectly classified validation points. We observed (1) generally high and varying levels of interpreter error; (2) a strong relationship between interpreter and classifier error; and (3) a net positive transfer of errors from reference data to classifiers. Because classifier error seems largely driven by interpreter error at the levels commonly observed in thematically detailed land-cover mapping, we (4) recommend strategies to reduce interpreter error before modelling.
Authors
Adam Eindride Naas Trond Simensen Lasse Torben Keetz Ingrid Vesterdal Tjessem Anders Bryn Rune Halvorsen Peter Horvath Ida Marielle Mienna Olav Skarpaas Joachim Paul Töpper Vigdis Vandvik Liv Guri Velle Catharina Caspara VloonAbstract
Field-based ecosystem maps are often used to support environmental impact assessments (EIAs) in later stages of spatial planning. During the early stages, however, information on geographical distributions of ecosystems is typically unavailable. This can result in uninformed decisions, with negative consequences for biodiversity and ecosystem services. Although model-based maps offer low-cost wall-to-wall coverage, they are rarely used for spatial planning. Using Norway as a study system, we aimed to: (1) quantify the coverage of field-based ecosystem maps in areas reserved for development; (2) use a model-based map to assess ecosystem extents in these areas; and (3) provide guidance on how model-based maps can support spatial planning. We first collated municipality-level land-use plans and intersected these with existing field-based ecosystem maps created for EIAs. Then, we constructed a model-based map for 17 ecosystem types with a 10 m × 10 m resolution that was intersected with the unsurveyed land-use plans. We estimated that 4.2 km2 of land is reserved for development in an average municipality, of which 0.3 km2 is covered by field-based maps. Our model-based map indicates, with moderate uncertainty, that 260 km2 covered by red-listed ecosystem types is at risk of being affected if unsurveyed land reserves are developed. However, improvements in model training and uncertainty quantification methodology should be considered to increase utility of the maps. We provide guidelines for using model-based ecosystem maps in spatial planning, especially in early planning stages, aiming to support decision-making while taking the limitations of model-based maps into account.
Authors
Gaute Velle Anders Bryn Kyrre Kausrud Lawrence R. Kirkendall Martin Malmstrøm Brett Kevin Sandercock Paul Ragnar Berg Kjetil Hindar Johanna Järnegren Erlend Birkeland Nilsen Eva Bonsak Thorstad Anders NielsenAbstract
This report examines how co-occurring non-native species can interact to create cumulative impacts on ecosystems. Non-native species may interact in additive, antagonistic, or synergistic ways. Through literature review, we found theoretical foundations and empirical examples showing that such interactions often occur. Synergistic interactions are of particular concern. Certain ecosystems appear particularly susceptible, including agricultural landscapes, urban environments, riparian systems, shipping-influenced marine areas, and islands with naïve fauna. We conclude that cumulative effects are ecologically important, and that it would be beneficial to incorporate multispecies interactions into risk assessments of non-native species in Norway.
2025
Authors
Ingrid Vesterdal Tjessem Peter Horvath Inger Kristine Følling Volden Adam Eindride Naas Michal Torma Anders BrynAbstract
Background The global climate is warming, especially in northern regions due to high-latitude amplification. This high-latitude warming leads to range expansion with advancing tree- and forest-lines (TFLs) in the Northern Hemisphere. However, empirical studies can rarely provide a well-documented elevational expansion rate, especially for timescales longer than 40–50 years. This study provides a unique long-term dataset on TFL dynamics of Betula pubescens subsp. czerepanovii in Norway, based on a combination of resampled historical data (n = 319) and new field registrations (n = 447). Our dataset includes a total of 766 registrations from five counties in Norway. In total, the dataset contains 439 treelines and 327 forest lines, most likely representing the highest recorded TFLs for the region at the given time. For all data, both resampled and new, locality, coordinates, elevation, aspect and spatial uncertainty and the resampling/sampling methods and definitions are provided. The entire material is stored and available for download through the Global Biodiversity Information Facility (GBIF) portal. New information This dataset includes newly-resampled TFLs, based on 57–127-year-old registrations. The entries provide elevational changes, georeferenced localities and potential sites for monitoring climate change effects. The entries enable regional analyses of TFL dynamics on intermediate timescales, including the effect of time lags. The material is available for modelling TFL range shifts along the boreal-alpine ecotone. This dataset most likely provides the highest registered Betula pubescens subsp. czerepanovii locations within their specific regions, thus representing the contemporary ecophysiological range limits for the life-form tree. Additional high-elevation TFL sites and localities have been added to make the material suitable for future remapping and monitoring of climatic TFL dynamics.
Authors
Michael A. H. Bekken Astrid Vatne Poul Larsen Andreas Ibrom Klaus Steenberg Larsen Bo Elberling Kristoffer Aalstad Sebastian Westermann Jacqueline K. Knutson Lena M. Tallaksen Peter Dörsch Peter Horvath Anders Bryn Norbert PirkAbstract
A controlled peatland rewetting experiment was conducted on two adjacent drained peatland sites in southeastern Norway. Eddy covariance monitoring of CO 2 and CH 4 fluxes at both sites began in 2019. In 2021, the Treatment Site was rewetted while the Control Site remained drained. Using nine environmental variables and the processed flux data as training data, Bayesian Additive Regression Tree (BART) models were used to generate annual flux balances for CO 2 and CH 4 . The 4-year mean annual flux at the Control Site was 17.3 ± 10 g CO 2 -C m − 2 yr − 1 and 4.6 ± 0.1 g CH 4 -C m − 2 yr − 1 . At the Treatment Site, the 2-year mean annual flux before the rewetting was 12.2 ± 3.8 g CO 2 -C m − 2 yr − 1 and 1.8 ± 0.04 g CH 4 -C m − 2 yr − 1 . In the first year after rewetting the annual flux was 53.3 ± 13 g CO 2 -C m − 2 yr − 1 and 3.8 ± 0.3 g CH 4 -C m − 2 yr − 1 , and in the second year after rewetting the annual flux was 41.2 ± 18 g CO 2 -C m − 2 yr − 1 and 3.4 ± 0.4 g CH 4 -C m − 2 yr − 1 . BART counterfactual modeling was able to estimate the effect of the rewetting on CO 2 and CH 4 fluxes. Two years after the rewetting, the BART counterfactual modeling estimated that the cumulative fluxes had increased by 80.3 ± 49 g CO 2 -C m − 2 and 3.4 ± 0.47 g CH 4 -C m − 2 because of the rewetting. Carbon flux monitoring of both sites is ongoing as the Control Site remains drained and the soil and vegetation at the Treatment Site continues to adjust to the altered hydrological regime after rewetting.
Abstract
The value of genetic resources in agriculture is hard to overestimate as they are decisive for food safety, provide options for adaptation of future diet needs, and underpin a vast amount of biodiversity. To enable an effective conservation of these resources, we need knowledge about where they are located. The EU project GenRes Bridge showed that this knowledge is indeed modest at the European level. A source of genetic resources with particular potential for use in agriculture, e.g. related to the future adaptation to climate change, are crop wild relatives (CWR). Crop wild relatives are plant species categorized as wild relatives of cultivated plants and are used here as an indicator of genetic resources in the landscape. We therefore wanted to explore new ways of identifying hotspots of genetic resources, highlighting the landscape as a starting point. It is well established that landscape heterogeneity is closely related to biodiversity, although to our knowledge studies hitherto have rarely looked at the relation between landscape and genetic resources. Focusing on crop wild relatives, used here as an indicator for genetic resources in the landscape, we wanted to assess whether we could identify how landscape variation in topography and land cover has consequences for the spatial distribution of genetic resources that may be important in the future development of agriculture. Here we report the results from this pilot study where we have tested whether there is a correlation between landscape heterogeneity and agricultural genetic resources, using 5 x 5 km grid cells as spatial units. We used the presence of the crop wild relatives (CWR) which are prioritized for conservation in Norway as indicators of agricultural genetic resource diversity and extracted landscape heterogeneity descriptors from publicly available sources. The results from our study do suggest that landscape diversity could be a path worth following in searching for these resources in the landscape, and thus also important in decision-making on planning and management in these diverse landscapes.
Authors
Nina Johansen Hans Geir Eiken Simeon Rossmann May Bente Brurberg Monica Skogen Marta Bosque Fajardo Borghild Glorvigen Toril Eklo Finn-Arne Haugen Snorre Hagen Erik LysøeAbstract
Several aphid species pose serious treats to potato crops by causing direct damage to the plants and/or indirectly by transmitting viruses. Different morphological forms and phenotypic plasticity among aphids complicates taxonomy and identification and thus makes targeted pest management in potatoes challenging. To obtain an overview of aphids frequenting potato fields in Norway, we investigated seasonal and annual changes in aphid populations in five potato fields (58–64 °N) over a three-year period (2016–2018), using yellow pan traps. In total 2218 of the 6136 collected aphids were identified by traditional barcoding, meaning sequencing a ~ 650 fragment of the mitochondrial COI gene. This revealed 137 different species, of which 111 were identified at the species level. The remaining were identified only to the genus level, indicating potential novel species. The southernmost sampling location yielded the highest number of species and individual counts, although no clear correlations to climate factors (temperature/precipitation) was observed. Of the 111 species identified, at least 39 are potential vectors of potato virus Y (PVY) and nine species may also transmit potato virus A (PVA). Knowledge on virus vector and non-vector aphid abundance and phenology have the potential to improve pest management of potato cultivation.