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.
2017
Abstract
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Abstract
Det er ikke registrert sammendrag
Abstract
Background and aims Decomposition of the finest harvest residues is important for the carbon and nutrient cycle in forest ecosystems both before and after tree felling. We assumed that decomposition is dependent on harvest residue fraction and chemistry, soil temperature and moisture, and aimed at determining decomposition rates and nutrient dynamics of needles, twigs and fine roots from newly felled Picea abies trees in two sites with different climate and topography. Methods Decomposition of needles, twigs and fine roots in mesh bags was followed for up to six years and four years in harvesting sites in eastern and western Norway, respectively. The western site had a more humid climate and a steeper terrain than the eastern site. Results The mass loss after two years was significantly higher for needles (49–59%) than for twigs and fine roots (29–38%). Between sites, there was no significant difference between mass loss for neither needles nor twigs. Nitrogen accumulated in needles during the first year, but 35% of initial needle N had been released after three years. The initial needle and twig decomposition rate was dependent on soil moisture and topographic aspect. During the first three years, needle lignin concentrations retarded whereas P concentrations stimulated needle mass loss. For twigs, P concentrations stimulated mass loss, whereas higher soil temperatures reduced it. Conclusions Lignin and P concentrations of plant parts and soil temperature were the most important factors for the first three-year mass loss. The slow release of nutrients shows the importance of remaining needles, twigs and fine roots as a long-time nutrient source in the ecosystems under study.
Abstract
Det er ikke registrert sammendrag
Abstract
Norges klimagassregnskap for treprodukter - Rapportering av klimagassregnskapet til UNFCCC (United Nations Framework Convention on Climate Change) inkluderer for Norges del både rapportering under FNs klimakonvensjon og Kyotoprotokollen (KP). - Denne rapporten omhandler det som rapporteres for treprodukter (Harvested Wood Products, HWP). Dette rapporteres blant annet som årlige endringer i karbonlager («annual changes in carbon stocks») jamfør retningslinjer fra FN (IPCC 2014a). Endringene er begrenset til det som følger av nasjonal avvirkning. - Klimagassregnskapet til UNFCCC for treprodukter omfatter tre produktkategorier: trelast, trebaserte plater og papir- og kartongprodukter. Det enkelte land krediteres for nasjonalt forbruk og eksport av treprodukter, ikke for import. Nasjonalt forbruk og eksport rapporteres separat. - Aktivitetsdata for de tre produktkategoriene som rapporteres for treprodukter hentes fra FAO. Definisjonerne for de tre produktkategoriene som rapporteres er de samme som FAO bruker. - Norges klimagassregnskap estimerer lagerstørrelsen på nasjonal forbruk etter 1960 til å være 22 613 492 t C (-82 916 kt CO2) per 2014. Dette lageret har hatt en jevn økning etter 1961, siden århundreskiftet har det flatet ut. For eksport var det totale lageret i 2014 6 929 580 t C (-25 408 kt CO2)...
Authors
Annika Kangas Rasmus Astrup Johannes Breidenbach Jonas Fridman Terje Gobakken Kari T. Korhonen Matti Maltamo Mats Nilsson Thomas Nord-Larsen Erik Næsset Håkan OlssonAbstract
Det er ikke registrert sammendrag
Authors
Svetlana Saarela Johannes Breidenbach Pasi Raumonen Anton Grafström Göran Ståhl Mark J. Ducey Rasmus AstrupAbstract
This study presents an approach for predicting stand-level forest attributes utilizing mobile laser scanning data collected as a nonprobability sample. Firstly, recordings of stem density were made at point locations every 10th metre along a subjectively chosen mobile laser scanning track in a forest stand. Secondly, kriging was applied to predict stem density values for the centre point of all grid cells ina5m×5m lattice across the stand. Thirdly, due to nondetectability issues, a correction term was computed based on distance sampling theory. Lastly, the mean stem density at stand level was predicted as the mean of the point-level predictions multiplied with the correction factor, and the corresponding variance was estimated. Many factors contribute to the uncertainty of the stand-level prediction; in the variance estimator, we accounted for the uncertainties due to kriging prediction and due to estimating a detectability model from the laser scanning data. The results from our new approach were found to correspond fairly well to estimates obtained using field measurements from an independent set of 54 circular sample plots. The predicted number of stems in the stand based on the proposed methodology was 1366 with a 12.9% relative standard error. The corresponding estimate based on the field plots was 1677 with a 7.5% relative standard error.
Abstract
Det er ikke registrert sammendrag
Abstract
Det er ikke registrert sammendrag
Abstract
Despite global deforestation some regions, such as Europe, are currently experiencing rapid reforestation. Some of this is unintended woodland encroachment onto farmland as a result of reduced livestock pasture management. Our aim was to determine the likely impacts of this on exposure to ticks and tickborne disease risk for sheep in Norway, a country experiencing ecosystem changes through rapid woodland encroachment as well as increases in abundance and distribution of Ixodes ricinus ticks and tick-borne disease incidence. We conducted surveys of I. ricinus ticks on ground vegetation using cloth lure transects and counts of ticks biting lambs on spring pastures, where lambs are exposed to infection with Anaplasma phagocytophilum, the causative agent of tick-borne fever in livestock. Pastures had higher densities of I. ricinus ticks on the ground vegetation and more ticks biting lambs if there was more tree cover in or adjacent to pastures. Importantly, there was a close correlation between questing tick density on pastures and counts of ticks biting lambs on the same pasture, indicating that cloth lure transects are a good proxy of risk to livestock of tick exposure and tick-borne disease. These findings can inform policy on environmental tick control measures such as habitat management, choice of livestock grazing area and off-host application of tick control agents.