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.
2012
Forfattere
Peder Gjerdrum Birger EikenesSammendrag
Density is one of the most basic quality traits, influential for wood processing and most applications. The aim of this paper has been to present a mathematical model for dry density variation along spruce stems. 85 mature spruce trees were sampled from afforestation plantations at the west coast region of Norway. 20 mm wide cubes of clear wood were extracted from the pith outwards in north and south directions at 10 equidistant heights along the trunk. Green and dry weight and volume were recorded. In this way, the 85 stems yielded 523 disks and a total of 6019 valid observation sets. A mathematically expressed model for density variation is presented. Overall R2 = 0.64, of which between stem variation s = 35 kg/m3 accounts for two thirds. The model standard error is 32 kg/m3; however, the model fails to identify the most extreme density values. The most important results are the quantitative, mathematical form of the model, and the identification of a general density minimum at a certain distance from the pith.
Forfattere
Ari M. Hietala Halvor SolheimSammendrag
Det er ikke registrert sammendrag
Forfattere
Halvor SolheimSammendrag
I 2009 ble rødbandsoppen registrert for første gang i Norge. De første par årene var angrepene forholdsvis beskjedne, men våren 2012 er det registrert sterke angrep i enkelte bestand. Rødbandsjuke har de siste 20 årene i stadig større omfang gjort skade på mange forskjellige furuarter og blir derfor regnet som en av de store klimavinnerne.
Forfattere
Halvor Solheim Carl Gunnar Fossdal Ari M. HietalaSammendrag
Vi har to arter av rotkjuke i Norge, gran- og fururotkjuke. Som navnet sier har de hvert sitt treslag som hovedvert, men begge kan gå på andre treslag, også løvtrær. Soppens spesielle biologi gjør at en kan forvente økede råteproblemer grunnet klimaendringer. Økt stormaktivitet gir mer rotrykking og lettere tilgang for rotkjuke, mens mildere klima med lengre vekstsesong gjør at perioden med sikker hogst blir kortere.
Forfattere
Gro SteineSammendrag
De bevaringsverdige storferasene har en årsavdrått som varierer fra ca 3 000 til 4 500 kg jølk pr år. Dølafe skiller seg ut ved at den rasen har lavere årsavdrått enn de andre rasene. Årsavdråtten for de bevaringsverdige rasene har ikke endret seg mye fra 2003 til 2011, men varierer en del fra år til år.
Sammendrag
Winter damage caused by frost is frequently observed on common ash (Fraxinus excelsior) in Norway. In spring 2007, extensive winter damage most likely camouflaged ash dieback caused by Chalara fraxinea. In 2008, ash dieback caused by C. fraxinea had spread to large areas in the southern part of Norway. The disease was widespread in forests and nurseries, but also on roadside trees, and in gardens and parks. In 2009, the disease had spread to new areas; about 30 km into Rogaland county in southwestern Norway and also further into some valleys in southeastern Norway.
Forfattere
Lars Sandved DalenSammendrag
God oversikt over skogressursene gir bedre utnyttelse og større verdiskaping. En ny metode gjør det nå mulig å beskrive også mindre skogområder ved hjelp av data fra tredimensjonale flyfoto.
Sammendrag
Phytophthora-arter er aggressive, sopplignende skadegjørere som fremmes av fuktig og mildt klima. I Norge er flere arter oppdaget på trær i paker eller skogholt nær hager. Varslede klimaendringer med økt temperatur og nedbør kan skape gode vekstforhold slik at flere arter kan etablere seg også i skogområder.
Sammendrag
Groundwater pollution by agrochemicals, degradation of soil quality and pollution of aquatic ecosystems by agricultural drainage waters have become an issue in the last decades. Flow processes in the vadose zone are closely related to these problems. In general, water flow in soils can be classified into two major categories: uniform and non-uniform (preferential) flow (In: U.S. National Committee for Rock Mechanics, Conceptual Models of Flow and Transport in the Fractured Vadose Zone, 2001, pp.149-187). The former describes a relatively slow movement of water through the porous soil matrix and can be modelled by Richard”s equation. The latter comprises all flow types where water bypasses a portion of the soil matrix and flows through localised (i.e. preferential) paths. Unlike uniform flow, preferential flow is hardly predictable because the assumptions of Richard”s equation of a homogeneous representative elementary volume characterised by a single value of water potential, water content and hydraulic conductivity are frequently violated (Eur J Soil Sci, 2007; 58:523-546)....
Sammendrag
From the range of information published, acetylation appears well suited to provide adequate protection against biological attack for materials derived from typically non-durable wood species. Acetylated wood is now commercially available both in Europe and in the USA. But still there are a lot of unanswered questions related to fungal decay mechanisms in acetylated wood.The paper summarize existing knowledge and highlight future research opportunities related to fungal deterioration of acetic anhydride modified wood. In addition statistical analyses based on previously published data were performed to quantify what factors contribute most to the performance (calculated as test sample/control).The results showed that WPG can explain approximately 50 % of the performance, measured as test sample/control (T/C), for acetic anhydride treated wood. Other of the applied variables, like wood species or type of fungus can reduce the variance in T/C by additional 15 %.