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
Forfattere
Peder Gjerdrum Knut Magnar SandlandSammendrag
Tre er utgangspunkt for allsidig arbeid, livsutfoldelse og velvære i vår del av verden. Et av de viktigste feltene for bransjens FoU for tiden er knyttet til tretørking. Den norske interessen henger nøye sammen med en internasjonal trend som drives av et ønske om å befeste og utvikle trelast som et konkurransedyktig materiale med forutsigbare egenskaper og konkurransedyktig pris. Dette kan bare oppnås gjennom grunnleggende teknologisk kompetanse og kunnskap om bruksområder og marked. Utviklingen går i retning av å ferdigtørke i én omgang, dvs. på sagbruket, og lasten må behandles slik at riktig tørkekvalitet bibeholdes helt frem til kunde og bruker.
Forfattere
Erik ChristiansenSammendrag
Det er ikke registrert sammendrag
Forfattere
Ketil KohmannSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Hans Olav EggestadSammendrag
Det er ikke registrert sammendrag
Forfattere
Tonje Økland Knut Rydgren Rune H. Økland Ken Olaf Storaunet Jørund RolstadSammendrag
Det er ikke registrert sammendrag
Sammendrag
We studied four south-facing and three north-facing boreal spruce forest stands (ca. 0.1ha each) in SE Norway with the aim of testing the hypothesis that former logging has long-term effects on boreal forest-floor vegetation. The stand series comprised unlogged natural forests and forests that were selectively or clear cut 6070 years prior to our study. Each stand was described with respect to history of forestry impact and tree-stand structure.Environmental, species number, species abundance and species composition (vegetation gradients obtained as ordination axes) variables obtained for 25 m1m plots in each stand were tested for among-stand differences. Significant among-stand differences were found, partly related to former forest management and partly due to among-stand differences in topography.Differences among stands related to management were found for tree stand density, highest in managed stands, and for Dryopteris expansa agg. and Luzula pilosa abundances, peaking in formerly clear-cut stands. Species number (at plot or stand scales) was weakly related to former management.On southerly as well as northerly aspects, gradients in species composition were found that separated plots according to former management. Differences among stand conditioned on topography resulted in opposite patterns in the two series of stands because among southerly stands the clear cut was the least while among northerly the clear cut was the most strongly sloping. Low-inclination sites tended more strongly to be paludified and to have high Sphagnum cover, and to have low abundance of specific microsites with small mosses and hepatics. Vegetation gradients related to soil moisture and microtopography were found for both aspects.A strong gradient in species composition related to tree influence at within-stand scales was found, with variation in species number. Existence of such a gradient should provide for significant biotic effects (of short or long duration) of the environmental changes that take place during forest re-growth: (1) the immediate creation of small or large tree-layer gaps by tree felling; and (2) the closing of the tree layer during the regeneration phase.Most notably, the phases at which the tree layer reaches minimum and maximum cover, respectively, may act as `bottlenecks\" for survival of forest-floor species. We conclude that forestry impacts understorey vegetation by way of changes in tree-layer structure and, to a lesser extent, substrate availability and the local environment, during forest regrowth. The extent and duration of this impact will depend on a complex set of factors.Our results are consistent with the view that if maintenance of species diversity is aimed at, environmental considerations should be built into forest management practices, preferably by mimicking the natural structural dynamics of the tree layer.
Sammendrag
Wintering ability in the field and resistance to different winter-stress factors under controlled environmental conditions were studied in a full-sib family of perennial ryegrass (Lolium perenne L.). Significant variation in tolerance to freezing and ice encasement, resistance to pink snow mould (Microdochium nivale) and also in winter survival and spring growth were found between the different genotypes. No strong correlations were found between the resistances to the different stress factors. These results indicate that resistance to different winter-stress factors is controlled by separate genes in perennial ryegrass. A low but significant positive correlation was found between spring growth of plants in the field after the first winter and both freezing tolerance and M. nivale resistance measured in controlled environments. Cold hardening seemed to influence freezing tolerance and M. nivale resistance differently in the different genotypes, since no distinct correlation in tolerance to freezing or resistance to M. nivale was found between unhardened and hardened plants. Tolerance or resistance to most of the winter stress factors measured was positively correlated with plant size.
Forfattere
Peder Lombnæs Bal Ram SinghSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars NesheimSammendrag
Ved beiting og ved fôring av ferskt gras vil det vere ønskjeleg med eit høgt innhald av sukker i fôret fordi mikroorganismane i vomma utnyttar sukkeret godt som energikjelde. Dessutan vil eit høgt sukkerinnhald vere gunstig for fôropptaket og for einsileringseigenskapane til fôret. Ved Institute of Grassland and Environmental Research (IGER) i Storbritannia er det laga sortar av fleirårig raigras som har høgare innhald av sukker enn det som er vanleg. I 2001 kom det i gang eit EU-prosjekt med føremål å undersøkje verknader av å nytte sortar av raigras med høgt innhald av sukker i fôrproduksjonen. Prosjektet vert leia av IGER i Wales, og forskingsinstitutt i Irland, Noreg, Sverige og Tyskland deltek i arbeidet. Her er det vist førebels resultat frå dei to første åra av den norske delen av prosjektet.