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.
2011
Forfattere
Lars Sandved DalenSammendrag
I skogen pågår en intens kamp mellom barkbille og gran. Forskning avdekker hvordan treet forsvarer seg med biokjemiske våpen, mens barkbilla, hvis den får overtaket, kan felle enorme skogområder.
Sammendrag
A changing climate will likely influence the selection of tree species in the future, and this may in turn affect the size of the pools and fluxes of carbon. Tree species differ in growth rate, fine-root turnover and quality of litter and tend to produce different types of understory vegetation. In Sweden three tree species (Norway spruce [Picea abies] 43%, Scots pine [Pinus sylvestris] 39% and birch [Betula spp.] 11%) dominate. In the present study we used field experiments in southern Sweden to test if these tree species differed in root distribution and turnover.
Sammendrag
Biodiversity is assumed to have high value for many people, but the necessary preservation also incurs a cost for the forest owner. Typically, studies of this cost are at the stand level, and hence, not very accurate as the cost may vary even within the stand. In this work, we use a 1m×1m grid, generated from LIDAR data, to estimate the cost for harvesting and forwarding. The method could be utilized to calculate compensation, and to select between key woodland habitats to minimise the cost. In three of four test cases, the main cost was reduced harvested volume, but in one case the key woodland habitat also made the harvesting operations more expensive.
Forfattere
Daniele Castagneri Ken Olaf StoraunetSammendrag
A long-term increase in radial tree growth has been reported in tropical (Lloyd & Farquhar 2008), temperate (Spiecker 1996, Voelker et al. 2006), alpine (Rolland et al. 1998) and boreal forests (Hofgaard et al. 1999) over the last decades. Variations in forest growth patterns have been ascribed to different causes, such as longer growing seasons due to climate warming (Hu et al. 2010), changes in land management practices (Hunter & Shuck, 2002), nitrogen deposition (Magnani et al. 2007), and atmospheric CO2 enhancement (Voelker et al. 2006). Tree-ring analyses provide detailed information on the past growth of forests. In order to assess the effect of climate change on forest growth, non-climatic variation should be removed from treering series. The effect of endogenous (inter-tree competition) and exogenous (insects attacks, fires, storms, human influence, etc.) disturbances on tree-ring series can be detected and reduced by considering trees from different sites. Furthermore, as tree-ring width generally decreases as trees grow older and larger, age-related growth trend should be removed, to preserve climatic lowfrequency variability of chronologies. Different detrending methods used to remove non-climatic variations need to be adapted to the objectives of a particular study....
Forfattere
Kjell Andreassen Bernt-Håvard ØyenSammendrag
Fourteen Nordic increment functions have been validated by use of with a test data set from long-term research plots in Norway of even-aged, pure stands of Scots pine, Birch and Norway spruce. In selected functions from Denmark, Finland, Norway and Sweden measures of site productivity, mean tree size and various stand characteristics are represented. Different models display both strengths and weaknesses in their predicting ability. Some measures of precision and bias have been calculated and the functions are ranked due to their performance. Basal area increment models for spruce and pine from Sweden, and a Finish volume increment model for birch has the best fit to the Norwegian test data. Some of the growth models developed outside Norway estimate the growth with about the same accuracy as the models frequently used and developed in Norway. The results indicate that forest conditions and traditional even-aged forest management practice in the Nordic countries seem to have small influence on the relative growth of even-aged stands. By careful recalibration of existing functions from other Nordic countries with data from Norway, a reasonable accuracy could be achieved in Norwegian forest with a reduction of the bias.
Sammendrag
Askeskuddsjuke er på frammarsj i Norge og i Europa. I 2010 var det imidlertid ikke så dramatisk som året før, men på våre overvåkingsflater har vi registrert en liten nedgang i kronetetthet. Så det er all grunn til fortsatt bekymring. Det er stor forskningsaktivitet i mange land, og nå vet vi også hvilken sopp som er årsaken. I tillegg begynner det å komme rapporter om andre askearter som er mottakelige for sjukdommen.
Forfattere
Bruce Talbot Morten NittebergSammendrag
In the coastal region of Norway, large volumes of relatively inaccessible plantation timber are maturing for harvest. The economic feasibility of accessing much of this timber has limited the level of harvesting activity considerably. Harvesting planners are faced with the classic dilemma of finding the appropriate level of investment in infrastructure, as against inoptimal transportation. In this paper, we present results from a simple deterministic simulation carried out to illustrate the efficiency frontiers of three transport methods, one of which requires a substantial investment in road upgrading. Results depend on assumptions made, but clearly show that in these conditions, upgrading roads for truck+trailer transport should be evaluated on a cases by case basis. Forest road length and condition, public road distance to conversion site, and investment level all play important roles in the decision structure. In the coastal regions, road upgrades would generally need to be justified by benefits other than timber harvesting alone.
Forfattere
Christian PedersenSammendrag
Mange av fugleartene som finnes i jordbrukets kulturlandskap sliter i Europa, men også i Norge. I Norge er det 3Q-prosjektet til Norsk institutt for skog og landskap som gjennomfører overvåkning av fugler i jordbrukslandskapet – i tett samarbeid med Norsk Ornitologisk Forening.
Forfattere
Lars Sandved DalenSammendrag
No kan du gå på nettet og sjå økologisk kart over Norge. Det er resultat av 40 års arbeid og kan bli spesielt viktig for beitenæringa.
Forfattere
Lars Sandved DalenSammendrag
Treng du hjelp til å finne bær, jaktbytte eller godt beite? Løysinga kan vere eit økologisk kartverk som dekkjer over 20 000 km² av Noreg, og som no blir tilgjengeleg for alle.