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
Det er ikke registrert sammendrag
Forfattere
Johannes Breidenbach Clara Antón Fernández Hans Petersson Ronald E. McRoberts Rasmus AstrupSammendrag
National Forest Inventories (NFIs) provide estimates of forest parameters for national and regional scales. Many key variables of interest, such as biomass and timber volume, cannot be measured directly in the field. Instead, models are used to predict those variables from measurements of other field variables. Therefore, the uncertainty or variability of NFI estimates results not only from selecting a sample of the population but also from uncertainties in the models used to predict the variables of interest. The aim of this study was to quantify the model-related variability of Norway spruce (Picea abies [L.] Karst) biomass stock and change estimates for the Norwegian NFI. The model-related variability of the estimates stems from uncertainty in parameter estimates of biomass models as well as residual variability and was quantified using a Monte Carlo simulation technique. Uncertainties in model parameter estimates, which are often not available for published biomass models, had considerable influence on the model-related variability of biomass stock and change estimates. The assumption that the residual variability is larger than documented for the models and the correlation of within-plot model residuals influenced the model-related variability of biomass stock change estimates much more than estimates of the biomass stock. The larger influence on the stock change resulted from the large influence of harvests on the stock change, although harvests were observed rarely on the NFI sample plots in the 5-year period that was considered. In addition, the temporal correlation between model residuals due to changes in the allometry had considerable influence on the model-related variability of the biomass stock change estimate. The allometry may, however, be assumed to be rather stable over a 5-year period. Because the effects of model-related variability of the biomass stock and change estimates were much smaller than those of the sampling-related variability, efforts to increase the precision of estimates should focus on reducing the sampling variability. If the model-related variability is to be decreased, the focus should be on the tree fractions of living branches as well as stump and roots.
Forfattere
Per VesterbuktSammendrag
Denne rapporten presenterer skjøtselsplaner for 6 lokaliteter med slåttemark (5 i Stjørdal kommune, 1 i Namdalseid kommune) på oppdrag fra Fylkesmannen i Nord-Trøndelag. Arbeidet er utført i forbindelse med nasjonal handlingsplan for slåttemarker, en naturtype som i dag er sterkt truet i Norge.
Forfattere
Georgia S. Papoutsi Andreas C. Drichoutis Rodolfo M. Jr. NaygaSammendrag
Det er ikke registrert sammendrag
Forfattere
Thiago de Castro Vitalis Wekesa Rafael de Andrade Moral Borges Demetrio Italo Jr Delalibera Ingeborg KlingenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Kyststripa av Noreg er prega av eit klima med mykje nedbør, særleg frå tidleg haust til sein etterjulsvinter. Nedbørsmengda har auka frå 30-årsnormalen 1931-1960, og er venta å auka ytterlegare.
Forfattere
Samson Øpstad Atle HaugeSammendrag
Før ein set i gang med omattgrøfting, må ein finna kva som er feil med det gamle grøfteanlegget. Vedlikehald kan lengja levetida til eit grøftesystem. På areal utsett for rustutfelling må det utførast spyling av grøfterøyra for å unngå tiltetting. Opne kanalar må reinskast for å sikra godt avlaup og at grunnvatnet ikkje vert ståande for høgt.
Forfattere
Eric N. Hansen Erlend Nybakk Rajat PanwarSammendrag
The recent economic downturn severely affected the US forest sector from a macro-economic perspective but little is known about changes in firm-level performance. In this study we investigate the changes in financial, social and environmental performance of forest sector firms during a period approximately corresponding to the downturn. We also assess industry dynamism and industry’s view about social and environmental responsibility as a competitive tool. We conducted a national survey of wood, furniture and paper companies. Approximately sixty percent of our respondents reported a decline in financial performance during the downturn. With respect to social and environmental performance, customer oriented actions show mixed trends, employee matters remained somewhat unaltered, community engagement significantly decreased, and engagement in environmental activities significantly increased. Respondents view their operating business environment as highly dynamic and difficult and they do not view engagement in social and environmental responsibility activities leading to either financial or non-financial benefits.
Sammendrag
Rot fungi are a major problem in the construction sector, and method to study under which moisture and temperature coefficients they grow are therefore of significant interest. Measurements of heat production rate have been made on wood samples with the brown rot fungus Postia placenta at different moisture contents (MCs). The results clearly show the heat production rate (ameasure of respiration rate and fungal activity) is moisture-dependent. For most cases, less heat was produced when the MC was decreased, and more heat was produced when the MC was increased. It was also found that when the MC increased after a dry period, the increase in activity was significantly delayed. However, if the moisture state was then kept constant at a high level, the activity slowly increased, showing that the fungi need time to recover back to the original activity level after drying. Isothermal calorimetry is a measurement technique well suited for the study of the activity of wood-decaying fungi as a function of temperature and moisture content.
Forfattere
Sveinn Are Hanssen Jan Ove Bustnes Lisbeth Schnug Sophie Bourgeon Trond Vidar Johnsen Manuel Ballesteros Christian Sonne Dorte Herzke Igor Eulaers Veerle Jaspers Adrian Covaci Marcel Eens Duncan John Halley Truls Borg Moum Rolf Anker Ims Kjell E ErikstadSammendrag
Parasites are natural stressors that may have multiple negative effects on their host as they usurp energy and nutrients and may lead to costly immune responses that may cause oxidative stress. At early stages, animals may be more sensitive to infectious organisms because of their rapid growth and partly immature immune system. The objective of this study was to explore effects of parasites by treating chicks of two raptor species (northern goshawk Accipiter gentilis and white-tailed sea eagle Haliaeetus albicilla) against both endoparasites (internal parasites) and ectoparasites (external parasites). Nests were either treated against ectoparasites by spraying with pyrethrin or left unsprayed as control nests. Within each nest, chicks were randomly orally treated with either an antihelminthic medication (fenbendazole) or sterile water as control treatment. We investigated treatment effects on plasma (1) total antioxidant capacity TAC (an index of nonenzymatic circulating antioxidant defenses), (2) total oxidant status TOS (a measure of plasmatic oxidants), and (3) immunoglobulin levels (a measure of humoral immune function). Treatment against ectoparasites led to a reduction in circulating immunoglobulin plasma levels in male chicks. TOS was higher when not receiving any parasite reduction treatment and when receiving both endo- and ectoparasitic reduction treatment compared with receiving only one treatment. TAC was higher in all treatment groups, when compared to controls. Despite the relatively low sample size, this experimental study suggests complex but similar relationships between treatment groups and oxidative status and immunoglobulin levels in two raptor species. Costs of parasitism, immunoecology, immunoglobulin, oxidative status.