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.
2006
Forfattere
Peder GjerdrumSammendrag
Most (all?) equipment waste timber by turning 10% of valuable solid wood into sawdust and allowance. The presentation discusses the problem and suggests a technology project to splitting blocks of modest size with new, strong materials for thin kerfs and optimised in yield and product quality rather than in speed.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Ken Olaf StoraunetSammendrag
In recent years attention has focused on the consequences of modern forestry on biological diversity. Additionally, past forest management has reduced the structural heterogeneity of forest landscapes, increasing the interest in assessing forest naturalness. General forest history of Norway shows that single-tree and selective logging was the main silvicultural method up to the mid-twentieth century when clearcutting practice took over as the dominating logging regime. Thus, regenerating forests on former clearcut areas have barely reached the stages of maturity, implying that mature forests of today for the most part are remnants from the period of selective logging. This thesis has been part of a comprehensive research project where one of the general objectives was to gain knowledge on the distribution and abundance of rare and threatened species in Norwegian forests....
Forfattere
Lone Ross GobakkenSammendrag
Det er ikke registrert sammendrag
Sammendrag
According to previous studies, short day (SD) treatment may increase frost hardiness in Picea abies (L.) Karst. seedlings during shoot elongation the next year. The purpose of this study was to examine how timing of the SD treatment affects spring frost hardiness. The following four treatments were applied in the first growth period: natural photoperiod (Nat), or SD treatment (8/16 h, day/night) either from 14-28 July (SD1), 28 July-11 August (SD2), or 11 20 August (SD3). After 125 days in the cold store (October-January), the seedlings were transferred to forcing conditions (20-25oC, 24 h photoperiod) followed by freezing tests at 3, -5, -7 and 9oC when most seedlings had reached bud break stage 7 (Krutzsch index). Seedling height measurements and analyses of carbohydrate status, nitrogen concentration and dry weight of needles after cold storage were done to examine the treatments` impact on seedling quality. SD treatment reduced visual freezing injury to current- and first-year shoots. Mortality occurred at –7 and –9oC and was significantly higher in treatments Nat and SD1 (43% in both) than in the SD2 (23%) and SD3 (15%) treatments. Seedlings from the late SD treatments also showed better height growth and developed more shoots from dormant buds after freezing to –3 and –5oC. Collectively, these findings demonstrate the importance of proper timing of the SD treatment in relation to the seedlings’ natural growth rhythm.
Forfattere
Aksel GranhusSammendrag
Det er ikke registrert sammendrag
Forfattere
Aksel GranhusSammendrag
Det er ikke registrert sammendrag
Sammendrag
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Forfattere
Paal KrokeneSammendrag
Bark beetles and associated phytopathogenic fungi elicit defence responses in conifers that may interfere with beetle establishment and development. Norway spruce is serving as a useful model species for studies of induced defences elicited by beetle attacks, fungal inoculation, and treatment with chemical elicitors.When trees are pretreated with a sublethal dose of fungal inoculations or with the phytohormone methyl jasmonate they become much more resistant to subsequent bark beetle attacks or artificial mass inoculations with fungi. This induced disease resistance follows dose-response dynamics, is nonspecific with respect to the pretreatment organism, appears to be nonsystemic, takes weeks rather than days to become activated, and can also be activated by mechanical wounding alone.Application of methyl jasmonate to Norway spruce stems induces a massive increase in terpene levels and external resin flow on the stem, whereas no increase is observed in soluble phenolics. Methyl jasmonate-application also leads to significantly less bark beetle colonization, with shorter parental galleries and fewer eggs laid in treated bark. There were also reductions in the number of beetles produced and the mean dry weight per beetle in methyl jasmonate-treated bark. Furthermore, fewer beetles were attracted to conspecifics tunneling in MJ-treated bark.The exact mechanisms responsible for induced resistance in Norway spruce and other conifers have not been determined, but inducible anatomical defense responses such as changes in polyphenol-containing parenchyma cells (PP cells) in the phloem and induction of traumatic resin duct formation in the sapwood seem to play an important role.
Forfattere
Wenche E. DramstadSammendrag
Det er ikke registrert sammendrag