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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.

2003

Sammendrag

Distance-independent individual tree growth models based on about 30,000 observations from the National Forest Inventory and the Norwegian Forest Research Institute have been developed for the main tree species in Norway.The models predict 5-year basal area increment over bark for trees larger than 5cm at breast height. Potential input variables were of four types: size of the tree, competition indices, site conditions, and stand variables including species, mixtures and layers. The squared correlation coefficient (R2) varied from 0.26 to 0.55.The accuracy of the models was tested by comparing the individual tree models with Norwegian diameter increment models. The accuracy is similar, but individual tree models forecast diameter distributions directly. The inclusion of species mixture and layer as variables increases the reliability of the models in mixed and in uneven-aged stands

Sammendrag

Norsk institutt for skogforskning (Skogforsk) i Bergen etablerte i 1996 seks forsøk med 14 forskjellige treslag og provenienser i Nordland, Nord-Trøndelag, Møre og Romsdal, Hordaland, Vest-Agder og Akershus. På Stigersand, Eidsvoll i Akershus hos forsøksvertene Solveig og Hans Stigersand var de første juletrærne klare for hogst allerede i 2001. Kun seks år etter planting var balsamedelgran, fraseredelgran og tre provenienser av serbergran store nok til at juletreutbyttet kunne vurderes. Balsamedelgran fra Minnesota i USA hadde 71 % utbytte, mens serbergran fra Sarajevo i Bosnia hadde 67 % utbytte. Med formklipping og regulering av høydeveksten kunne utbyttet vært høyere, men dette var det ikke anledning til på grunn av forsøkseriens formål og design. Imidlertid er doble topper blitt klippet en gang

Sammendrag

The objective was to study the influence of vegetation cover, humus depth, microrelief and distance to seed tree edge on natural regeneration of Norway spruce (Picea abies (L.) Karst.) in five small clear-cuts on bilberry woodland in southeastern Norway. The impact of the vegetation was considered at tree different scales: at the growing point, in the nearest dm2 around the seedlings and at a 1m2 scale.Most of the regeneration (95%) developed in 1996, after a rich seed year in 1995. The microhabitat was of crucial importance to seedling establishment. Litter, Sphagnum spp. and Polytrichum commune were good substrates for establishment, while areas dominated by Deschampsia flexuosa, Dicranum spp. and Pleurozium schreberi had very few seedlings.Seedling survival after five growing seasons was slightly better in litter than in Sphagnum and other mosses, but the differences were not statistically significant. Increasing humus depth had a positive influence on regeneration, probably due to shallow soils at the sites.Even though depressions covered only 4.9% of the ground, 24.1% of the seedlings occurred here. Survival was, however, lower in depressions than in the other microrelief classes. Distance to the seed tree edge had a significant influence on establishment, with more seedlings establishing close to the edge.