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.
2010
Tidsskriftspublikasjon – Planter tilpasser seg klimaforandringer
Carl Gunnar Fossdal, Harald Kvaalen
Forfattere
Carl Gunnar Fossdal Harald KvaalenSammendrag
Trær og andre planter tilpasser seg endringer i klimaet. Bakom dette ligger det seleksjon og noen av genene det selekteres på har epigenetiske effekter, noe som gir økt fleksibilitet i graden man kan tilpasse seg forandringer. På Svalbard er det en rekke planter som er tilpasset de lokale forholdene i dag, og ved den estimerte klimaforandringen med høyere temperaturer, kan man forvente endringer i blomstringstid og at dvergbjørk og andre arter vil få økt utbredelse.
Sammendrag
Det internasjonale biomangfoldåret er på hell. Norge har, i likhet med flere andre land, satt 2010 som frist for å ”stoppe tapet av det biologiske mangfoldet”. Som en del av dette arbeidet fikk Norge i 2009 ny Naturmangfoldlov (Lov om forvaltning av naturens mangfold). I §23 i loven heter det at ”Kongen i statsråd kan ved forskrift utpeke nærmere angitte arter som prioritert.” Dette åpner for særskilte tiltak, og skal være et virkemiddel for å ta vare på arter som har problemer med å overleve. Men hvilke av de rundt 40.000 naturlig forekommende arter av dyr, planter og sopp i Norge skal prioriteres, og hvilke kriterier skal legges til grunn for utvelgelsen av disse artene?
Sammendrag
Mange juletredyrkarar har i dei seinare åra gjort gode erfaringar med fjelledelgran (Abies lasiocarpa), og fleire ønskjer å prøve treslaget. Riktig proveniensval og god kunnskap om lokalklimaet på dyrkingsstaden er viktig for å kunne lykkast med innførte treslag. Ei forsøksserie med frømateriale frå USA og Canada, viser at fjelledelgran frå delar av det nordlege og vestlege utbreiingsområdet er mest aktuell for dyrking i låglandet i Sør-Noreg.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
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Det er ikke registrert sammendrag
Forfattere
Tuula Kantola Mikko Vastaranta Xiaowei Yu Paivi Lyytikainen-Saarenmaa Markus Holopainen Mervi Talvitie Sanna Kaasalainen Svein Solberg Juha HyyppäSammendrag
Climate change has been observed to be related to the increase of forest insect damages in the boreal zone. The prediction of the changes in the distribution of insect-caused forest damages has become a topical issue in the field of forest research. The common pine sawfly (Diprion pini L.) (Hymenoptera, Diprionidae) is regarded as a significant threat to boreal pine forests. Defoliation by D. pini caused severe growth losses and tree mortality of Scots pine (Pinus sylvestris L.) (Pinaceae). Logistic regression is commonly used in modelling the probability of occurrence of an event. In this study the logistic regression was investigated for predicting the needle loss of individual Scots pines (pine) using the features derived from airborne laser scanning (ALS) data. The defoliation level of 164 trees was determined subjectively in the field. Statistical ALS features were extracted for single trees and used as independent variables in logistic regression models. Classification accuracy of defoliation was 87.8% as respective kappa-value was 0.82. For comparison, only penetration features were selected and classification accuracy of 78.0% was achieved (kappa=0.56). Based on the results, it is concluded that ALS based prediction of needle losses is capable to provide accurate estimates for individual trees.
Sammendrag
The airborne laser scanning (ALS) penetration rate, i.e. the ratio of ground echoes to total echoes, is a proxy for gap fraction. Hence, ALS has a potential for monitoring forest properties that are related to gap fraction, such as leaf area index, canopy cover and disturbance. Furthermore, two gap types may be distinguished: While a pulse that only produces a ground echo most likely hit a large, between-tree gap, a pulse that produces a ground echo as the last of several returns most likely hit smaller, within-canopy gaps. This may be utilized to distinguish between disturbance types such as defoliation and tree removal. However, the ALS penetration rate needs to be calibrated with gap fraction measurements in the field, because it is influenced by technical properties of the acquisition. The aim of this study was to quantify the magnitude of this influence, by comparing repeated acquisitions with different technical specifications. We had at hand 12 ALS acquisitions which could be combined into six pairs, from four spruce and pine dominated forests in Norway. We established 20x20 m grids, and for each grid cell we extracted three penetration variables: first echo penetration, last-of-many echo penetration, and total (i.e., first and last echo). We log-transformed the penetration variables (P1 and P2) from two laser acquisitions, and fitted the no-intercept, linear model log(P1) = log(P2), applying total least squares regression analysis. In a majority of the cases, the penetration variables were very similar, i.e. they deviated by <10%. For the first echo penetration the slopes varied from 0.87 to 1.07 and the R2 values ranged between 0.91 and 0.99. For the last-of-many echo penetration, there was generally weaker correspondence with slopes varying from 0.78 to 1.02, and R2 values ranging from 0.60 to 0.94. Finally, for the total penetration there was again stronger agreement with slopes in the range 0.83-1.03 and R2 values from 0.88 to 0.99. In conclusion, it seems that the penetration ability of different ALS scans in many cases are very similar, and further research may reveal ranges of standardized settings for which field inventory can be redundant.
Forfattere
Per Otto Flæte Gry Alfredsen Kristian Bysheim Øyvind Eriksen Anders Qvale Nyrud Birger VenneslandSammendrag
Roundwood timber is raw material for numerous products. Wood based products are generally recognised as favourable regarding energy consumption and greenhouse gas (GHG) emissions. Several studies have shown that the net CO2 emissions can be reduced by using biofuels harvested from forests to substitute fossil fuels, and by using wood for building materials. Energy use and GHG emissions associated with producing roundwood can be influenced by a broad range of factors, such as silvicultural practice, topography, applied technology, forestland ownership, industrial structure, etc. This emphasizes the importance of using representative data for energy use and GHG emissions when calculating environmental impacts. The aim of this study was to investigate the embodied energy and life cycle GHG emissions of industrial softwood sawlogs in Norway, covering the production chain from tree seed to log yard. Analyses were based on activity data for the Norwegian forest sector for the year 2007. The results showed that the embodied energy and GHG emissions were low compared with the energy and CO2-equivalents stored in the roundwood (about 2%). The findings from this study can be used to inform future decisions on processes in forestry that should be focused on when planning actions to reduce energy consumption and GHG emissions. Additionally, as roundwood timber is raw material for numerous products the results can be useful when preparing documentation of environmental impacts, such as environmental product declarations, which are increasingly demanded by the market.
Sammendrag
Modified wood can provide protection against a range of wood deteriorating organisms. But we still lack information about why the modified wood is protected from microbial attack. Several hypotheses have been put forward for the mode of action against wood decaying fungi, including inhibition of action of specific enzymes, but they still need further testing. In this study gene expression of the brown rot fungus Postia placenta FPRL 280 has been monitored after 2, 4 and 8 weeks of colonization in furfurylated Scots pine (Pinus sylvestris L.) and in untreated control samples. Preliminary results are given. The main finding was that genes related to oxidative metabolic activity generally was higher in furfurylated wood compared to untreated Scots pine. Carbohydrate metabolism related expression varied. For one endo-glucanase and two β-glucosidases the expression was lower in furfurylated wood compared to untreated control, while for one glucoamylase and one glucan 1,3b glucosidase the expression was higher in furfurylated wood. The four cytochrome P450 tested, involved in breakdown of toxic compounds, gave inconsistent results between furfurylated and untreated control samples. Phenylalanine ammonia lyase and cytosolic oxaloacetase gave higher expression in control than in furfurylated samples.