Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2000
Authors
Oddvar SkreAbstract
Mørkerespirasjonen i veksande skot av gran (Picea abies) er funnen å samsvara godt med den daglege lengdeveksten. Liknande er funnen i bladskiver av bjørk (Betula pubescens) og alm (Ulmus glabra). Dei årlege akkumulerte respirasjonssummane viste korrelasjon med utbreiingsgrensene for desse treslaga. Det har blitt gjort utrekningar av kva konsekvensar ein mogeleg auke i sommartemperaturen vil få. Over tid vil høgdegrensene for dei to treslaga stiga med opptil 400 meter. Forsøk med bjørk har vist at dette treslaget har stor evne til å tilpassa seg temperaturendringar ved hjelp av ulike kompensasjonsmekanismar.
Authors
Oddvar SkreAbstract
Forsøk viser at mørkerespirasjonen i veksande skot av norsk gran (Picea abies (L.)Karst.) har samanheng med den daglege veksten. Liknande samanhengar er funne i bladskiver av bjørk (Betula pubescens Ehrh.) og alm (Ulmus glabra var. scabra Huds.). Årleg akkumulert respirasjon viser korrelasjon med utbreiingsgrensene til desse treslaga. Det er venta at klimaendringa på langt sikt vil føra til at tregrensene for dei undersøkte treslaga vil stiga med 400 m. Forsøk med bjørk viser at dette treslaget har eit stort potensial for temperaturtilpassing ved ulike kompensasjonsmekanismar.
Abstract
No abstract has been registered
Authors
Svein Ole Borgen Per Ove RøkholtAbstract
No abstract has been registered
Authors
Peder GjerdrumAbstract
Manuskriptet beskriver en metode og et eksempel for å beregne kostnader ved trelasttørking, presentert for Cost E15 Workshop
Authors
Per Otto Flæte Olav Albert Høibø Frode Fjærtoft Tom-Nils NilsenAbstract
No abstract has been registered
Abstract
Relationships between crown density and growth of Norway spruce stands are presented, after removal of the effects of major natural influences. On 569 monitoring plots comprising 40 000 trees, crown density has been annually assessed during 1991 to 1996.Stand growth was determined from measurements of diameter and height in 1991 and in 1996. Various models explaining mean crown density and annual growth of the stands as a function of natural factors, like age and site index, were compared.The influence of the natural factors were then removed by recalculating crown density to residual values from one preferred model, and by recalculating growth to relative values given in percent of model predictions.Crown density and its residuals were positively correlated to growth. These relationships were weak in terms of their ability to explain variation (low R2). However, the various relationships consistently indicated that roughly 1% change in crown density corresponded to 1% change in growth. This relationship also included common spatial variation over Norway: a large part of southeast Norway had unexplained low crown density and unexplained low growth.Some other, smaller regional consistencies were found as well. The study supports the use of crown density assessments, and further it encourages the use of growth data in the search for major stress factors responsible for present forest condition.
Authors
Knut FinstadAbstract
No abstract has been registered
Authors
Erik Christiansen Alan A. Berryman Vincent R. Franceschi Trygve Krekling Paal Krokene Nina Elisabeth Nagy Halvor SolheimAbstract
No abstract has been registered
Abstract
A rapid and sensitive method was developed to discriminate between Seiridium cardinale and Seiridium cupressi, the fungi causing severe cankers on common cypress in the Mediterranean area. The method amplified sequence variants in the ITS2 region of ribosomal DNA using the polymerase chain reaction (PCR), followed by polyacrylamide gel electrophoresis, to reveal single-strand conformation polymorphism (SSCP) between the two species. The greatest separation pattern was obtained with a gel matrix containing 7-10% formamide and 3-5% glycerol under optimized running conditions, which were found to be 30-40 V at 4-5 degrees C for 4-8 h. Sequence homology among isolates within each of the two species caused no mobility shifts, with all isolates displaying the same migration pattern. A few base differences between S. cardinale and S. cupressi caused markedly different migration patterns, allowing differentiation of the two pathogens. Differences between these fungi at the genetic level are consistent with known data on morphological, physiological and pathogenic characteristics. SSCP analysis constitutes a rapid and easy-to-perform method by which to recognize and distinguish closely related organisms, and has considerable potential for use in diagnosis and taxonomy.