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.
2025
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Acetylation greatly increases the decay resistance of wood, but even highly acetylated wood can be degraded by fungi if given sufcient time. This study investigated the degradation of acetylated wood by the brown rot fungus Rhodonia placenta, aiming to understand the fungal-induced changes in wood-water relations that are associated with decay. Acetylated samples as well as unacetylated references were exposed to R. placenta in a stacked-sample decay test to generate samples in diferent stages of decay. The decayed samples were used to investigate changes in acetyl content, water vapour sorption, and maximum cell wall moisture content as measured by solute exclusion. R. placenta caused high mass losses in acetylated wood, but preferential deacetylation was seen only in highly acetylated samples in the early stages of decay. Acetylated samples showed increased hygroscopicity in sorption measurements as a result of R. placenta degradation, particularly at high relative humidity in desorption from the undried decaying state. The increase was very strong in the highly acetylated samples and took place at low mass losses, indicating that it may be at least partially related to the deacetylation of the wood material. Degradation also increased maximum cell wall moisture content, but the increase was stronger in the references than the acetylated samples, suggesting that the acetyl groups remaining in the samples continue to provide a cell wall bulking efect.
Forfattere
Lennart Noordermeer Terje Gobakken Johannes Breidenbach Rune Eriksen Erik Næsset Hans Ole Ørka Ole Martin BollandsåsSammendrag
Accurate field plot data on forest attributes are crucial in area-based forest inventories assisted by airborne laser scanning, providing an essential reference for calibrating predictive models. This study assessed how sample tree selection methods and plot data calculation methods affect the accuracy of field plot values of timber volume, Lorey’s mean height, and dominant height. We used data obtained from 12 420 circular sample plots of 250 m2, measured as part of the Norwegian national forest inventory and 45 local forest management inventories. We applied Monte Carlo simulations by which we tested various numbers of sample trees, methods to select sample trees, and methods to calculate plot-level values from tree-level measurements. Accuracies of plot values were statistically significantly affected by the number of sample trees, sample tree selection method, and calculation method. Obtained values of root mean square error ranged from 5% to 16% relative to the mean observed values, across the factors studied. Accuracy improved with increasing numbers of sample trees for all forest attributes. We obtained greatest accuracies by selecting sample trees with a probability proportional to basal area, and by retaining field-measured heights for sample trees and using heights predicted with a height-diameter model for non-sample trees. This study highlights the importance of appropriate sample tree selection methods and calculation methods in obtaining accurate field plot data in area-based forest inventories.
Forfattere
Monica Sanden Eirill Ager-Wick Johanna Eva Bodin Nur Duale Anne-Marthe Ganes Jevnaker Kristian Prydz Volha Shapaval Ville Erling Sipinen Tage ThorstensenSammendrag
The Norwegian Scientific Committee for Food and Environment (VKM) has assessed an application for approval of the genetically modified maize DAS1131 for food and feed uses, import and processing in the EU. In accordance with an assignment specified by the Norwegian Food Safety Authority (NFSA) and the Norwegian Environment Agency (NEA), VKM assesses whether genetically modified organisms (GMOs) intended for the European market can pose risks to human or animal health, or the environment in Norway. VKM assesses the scientific documentation regarding GMO applications seeking approval for use of GMOs as food and feed, processing, or cultivation. The EU Regulation 1829/2003/EC (Regulation) covers living GMOs that fall under the Norwegian Gene Technology Act, as well as processed food and feed from GMOs (dead material) that fall under the Norwegian Food Act. The regulation is currently not part of the EEA agreement or implemented in Norwegian law. Norway conducts its own assessments of GMO applications in preparation for the possible implementation of the Regulation. In accordance with the assignment by NFSA and NEA, VKM assesses GMO applications during scientific hearings initiated by the European Food Safety Authority (EFSA), as well as after EFSA has published its own risk assessment of a GMO, up until EU member countries vote for or against approval in the EU Commission. The assignment is divided into three stages. (link) Genetically modified maize DAS1131 DAS1131 is a genetically modified maize developed by Agrobacterium tumefaciens -mediated transformation. Maize DAS1131 plants contain the transgenes cry1Da2 and dgt-28 epsps which encode the protein Cry1Da2 and the enzyme DGT-28 EPSPS, respectively. Cry1Da2 provides resistance to certain susceptible Lepidopteran (order of butterflies and moths) pests and the enzyme DGT-28 EPSPS provides tolerance to glyphosate-based herbicides. VKM has assessed the documentation in application GMFF-2021-1530 and EFSA's scientific opinion on genetically modified maize DAS1131. VKM concludes that the applicant's scientific documentation for the genetically modified maize DAS1131 is satisfactory for risk assessment, and in accordance with EFSA guidelines for risk assessment of genetically modified plants for food or feed uses. The genetic modifications in maize DAS1131do not indicate an increased health or environmental risk in Norway compared with EU countries. EFSA's risk assessment is therefore sufficient also for Norwegian conditions. As no specific Norwegian conditions have been identified regarding properties of the genetically modified maize DAS1131, VKM's GMO panel has not performed a complete risk assessment of the maize. About the assignment: In stage 1, VKM shall assess the health and environmental risks of the genetically modified organism and derived products in connection with the EFSA scientific hearing of GMO applications. VKM shall review the scientific documentation that the applicant has submitted and possibly provide comments to EFSA. VKM must also consider: i) whether there are specific Norwegian conditions that could give other risks in Norway than those mentioned in the application, ii) whether the Norwegian diet presents a different health risk for the Norwegian population should the GMO be approved, compared to the European population, and iii) risks associated with co-existence with conventional and/or ecologic production of plants for GMOs seeking approval for cultivation. Relevant measures to ensure co-existence must also be considered. In stage 2, VKM shall assess whether comments from Norway have been satisfactorily answered by EFSA. In addition, VKM shall assess whether comments from other countries imply need for further follow-up. (...)
Sammendrag
I økologisk landbruk er det et mål at gårder med husdyr skal være mest mulig selvforsynt med fôr. Minimumskravet til egenprodusert fôr har over tid blitt høyere. Rapporten presenterer ni økologiske melkeproduksjonsbruk med produksjonsdata og gårdbrukernes tanker om og prioriteringer med hensyn til selvforsyning med fôr. Vi har beregnet ulike mål på gårdenes selvforsyningsgrad og diskuterer hvordan ulike strategier på gårdene virker inn på disse resultatene. De ni økologiske melkebrukene ble valgt ut for å representere ulike klimatiske forhold og tilnærminger til selvforsyning. Data ble samlet inn i 2018 gjennom intervjuer med gårdbrukerne. Resultatene viser at selvforsyning med fôr var et viktig mål for de økologiske melkeprodusentene, først og fremst styrt av egne verdier og mål for økologisk landbruk. Studien viser at ulike strategier kan brukes for å oppnå høy selvforsyningsgrad, avhengig av gårdens beliggenhet, arealgrunnlag, melkekvote og økonomiske situasjon. Bøndenes strategier for å øke eller beholde høy selvforsyningsgrad inneholdt ulike agronomiske tiltak: øke grovfôrkvaliteten gjennom forbedret gjødselhåndtering, drenering og oftere fornyelse av enga. Noen gårder kombinerte høy ytelse med egen produksjon av korn, proteinvekster og oljevekster, mens andre økte selvforsyningsgraden ved å redusere kraftfôrnivået. Alle gårdene i denne studien hadde en høy selvforsyningsgrad med fôr. I 2017 hadde alle over 70 % fôr fra gården eller regionen, medberegnet kraftfôr, som var kravet til regelverket som trådte i kraft i 2024. Selvforsyningsgraden til gårdene varierte mellom 61 % og 100 % på tørrstoffbasis når kun fôr produsert på gården ble inkludert, og mellom 78 % og 100 % når også norskprodusert fôr ble inkludert.
Forfattere
David Chludil Curt Almqvist Mats Berlin Arne Steffenrem Steven E. McKeand Jiří Korecký Jan Stejskal Jaroslav Čepl Fikret Isik Debojyoti Chakraborty Silvio Schueler Torsten Pook Christi Sagariya Milan LstibůrekSammendrag
Det er ikke registrert sammendrag
Forfattere
Sean P Healey Zhiqiang Yang Angela M Erb Ryan Bright Grant M Domke Tracey S Frescino Crystal B SchaafSammendrag
Rapidly maturing frameworks for investing in and committing to mitigation of climate change through forest management have focused almost exclusively on the benefits of carbon sequestration, without accounting for collateral changes in geophysical factors such as surface albedo. Newly available 30 m albedo retrievals derived from imagery acquired by the Landsat 8 satellite, analyzed at 273 652 field plots monitored by the United States Forest Service, suggest that large areas of the US Inter-Mountain West’s forests have a net warming impact on the planet’s surface energy balance. For the conterminous US, the impacts of albedo offset approximately half of the recognized non-soil forest carbon storage benefit. The emerging capacity to resolve albedo evolution at the scale of a large number of inventory plots also provides unprecedented empirical evidence that albedo impacts vary strongly as a function of both tree age and species group. This research highlights a correctable source of uncertainty in operational monitoring of forest-climate interactions, and it may temper expectations for forest establishment as a means of mitigating global climate change.
Sammendrag
Accurately predicting whether pedestrians will cross in front of an autonomous vehicle is essential for ensuring safe and comfortable maneuvers. However, developing models for this task remains challenging due to the limited availability of diverse datasets containing both crossing (C) and non-crossing (NC) scenarios. Therefore, we propose a procedure that leverages synthetic videos with C/NC labels and an untrained model whose architecture is designed for C/NC prediction to automatically produce C/NC labels for a set of real-world videos. Thus, this procedure performs a synth-to-real unsupervised domain adaptation for C/NC prediction, so we term it S2R-UDA-CP. To assess the effectiveness of S2R-UDA-CP in self-labeling, we utilize two state-of-the-art models, PedGNN and ST-CrossingPose, and we rely on the publicly-available PedSynth dataset, which consists of synthetic videos with C/NC labels. Notably, once the real-world videos are self-labeled, they can be used to train models different from those used in S2R-UDA-CP. These models are designed to operate onboard a vehicle, whereas S2R-UDA-CP is an offline procedure. To evaluate the quality of the C/NC labels generated by S2R-UDA-CP, we also employ PedGraph+ (another literature referent) as it is not used in S2R-UDA-CP. Overall, the results show that training models to predict C/NC using videos labeled by S2R-UDA-CP achieves performance even better than models trained on human-labeled data. Our study also highlights different discrepancies between automatic and human labeling. To the best of our knowledge, this is the first study to evaluate synth-to-real self-labeling for C/NC prediction.
Forfattere
Shaohui Zhang Poul Erik Lærke Mathias Neumann Andersen Junxiang Peng Esben Øster Mortensen Johannes Wilhelmus Maria Pullens Sheng Wang Klaus Steenberg Larsen Davide Cammarano Uffe Jørgensen Kiril ManevskiSammendrag
Under optimal growth conditions, net primary productivity (NPP) is a product of intercepted photosynthetic active radiation (Ipar) and maximum radiation use efficiency (RUEmax; conversion of Ipar to biomass). The objective of this study was to improve and validate the RUEmax-based Carnegie-Ames-Stanford Approach (CASA) for the determination of grassland NPP by canopy multispectral reflectance collected at field (handheld sensor) and airborne (UAV) scale considering environmental constraints. The analysis was based on multi-year field experiments on sandy loam soil in Denmark, measured shoot and estimated root biomass to calculate NPP, long-term meteorological data, and daily NPP estimated from CO2 flux chamber measurements for deriving environmental constraints. The results derived from CO2 flux data showed that NPP and plant respiration were higher in the middle of the season before the second harvest when temperature was also high. The daily maximum air temperature optimal for grass biomass production was 16.5 °C. The improved CASA model built in this study was accurate for modeling NPP at both daily (nRMSE decrease of 9 %) and seasonal (nRMSE decrease of 8–34 %) scales when considering the best environmental constraints such as maximum air temperature, vapor pressure deficit, cloudiness, and water stress, compared to no constraints. Maximum air temperature and water stress were the most important environmental constraints to the grass RUEmax. Seasonal RUEmax for modeling NPP after considering best environmental constraints was 1.9–2.7 g C MJ−1 for ryegrass and 1.9–2.2 g C MJ−1 for grass-legume mixture using the two remote sensors for measuring spectral reflectance. Over the whole growing season, tall fescue (3.1 g C MJ−1) and festulolium (2.9 g C MJ−1) obtained higher RUEmax than perennial ryegrass (2.3 g C MJ−1). This study highlights the practical implications of using the CASA model improved by maximum temperature and water stress functions for real-time, remote sensing-based assessments of grassland productivity.
Sammendrag
Environmental observation networks, such as AmeriFlux, are foundational for monitoring ecosystem response to climate change, management practices, and natural disturbances; however, their effectiveness depends on their representativeness for the regions or continents. We proposed an empirical, time series approach to quantify the similarity of ecosystem fluxes across AmeriFlux sites. We extracted the diel and seasonal characteristics (i.e., amplitudes, phases) from carbon dioxide, water vapor, energy, and momentum fluxes, which reflect the effects of climate, plant phenology, and ecophysiology on the observations, and explored the potential aggregations of AmeriFlux sites through hierarchical clustering. While net radiation and temperature showed latitudinal clustering as expected, flux variables revealed a more uneven clustering with many small (number of sites < 5), unique groups and a few large (> 100) to intermediate (15–70) groups, highlighting the significant ecological regulations of ecosystem fluxes. Many identified unique groups were from under-sampled ecoregions and biome types of the International Geosphere-Biosphere Programme (IGBP), with distinct flux dynamics compared to the rest of the network. At the finer spatial scale, local topography, disturbance, management, edaphic, and hydrological regimes further enlarge the difference in flux dynamics within the groups. Nonetheless, our clustering approach is a data-driven method to interpret the AmeriFlux network, informing future cross-site syntheses, upscaling, and model-data benchmarking research. Finally, we highlighted the unique and underrepresented sites in the AmeriFlux network, which were found mainly in Hawaii and Latin America, mountains, and at under- sampled IGBP types (e.g., urban, open water), motivating the incorporation of new/unregistered sites from these groups.