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.
2002
Forfattere
Bjørn ØklandSammendrag
Several studies conclude that sun-exposed habitats with sufficient supply of dead wood are essential for many saproxylic and mycetophagous beetle species in forests. This has induced Scandinavian foresters to leave artificial tall stumps on clear-cuts in spruce forests.In the present study of Norway spruce forest, habitat preferences during flight were studied for saproxylic and mycetophagous beetles recorded as sporocarp-visitors of Fomitopsis pinicola and Fomes fomentarius, using 690 randomly placed window traps in 69 sites covering three forest types: clear-cuts, young and oldgrowth stands.Many of the sporocarp-visitors showed a strong preference for oldgrowth forest, avoiding clear-cuts and young replantations. By stepwise linear multiple regression, presence of canopy cover appeared as a major factor while variables associated with sporocarps and dead wood were most often secondary in importance. The results indicate that sufficient canopy cover is important for many sporocarp-visiting beetles in Norway spruce forests
Forfattere
Galina N. Koptsik S. Teveldal Sergey V. Koptsik Lars StrandSammendrag
No abstract has been registered
Forfattere
Harald Kvaalen Ola Gram DæhlenSammendrag
No abstract has been registered
Forfattere
Inger Sundheim Fløistad G.G. PatilSammendrag
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth.The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron.Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF.The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.
Forfattere
O. Janne Kjønaas Isabella Børja Nicholas Clarke Heleen A. de Wit Lars Strand Hooshang MajdiSammendrag
No abstract has been registered
Forfattere
Erlend Ystrøm Haartveit Per Otto FlæteSammendrag
Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) were measured on lumber from trees originating from four stands in each of the countries Norway and Sweden. Half of the stands were monocultures of Norway spruce while the remainder were mixed stands of Norway spruce and birch species.No significant differences in MOE and MOR were found between Norway spruce lumber grown in monocultures and lumber originating from mixed stands. Furthermore, there were no significant differences between the two groups concerning wood density, mean annual ring width and diameter of the largest knot in each log.These three variables also yielded similar models for lumber originating from monocultures and mixed stands, respectively, when used as independent variables in simple regression models for MOE and MOR.PLS1 regression models, with a X-matrix of variables measurable with simple equipment on trees and logs, were used to sort logs according to predicted values of MOE and MOR. The models show promising results with respect to pre-sorting of logs in order to create a better fit between the quality of logs and the expected properties of the final products.When sorting logs, a high percentage is correctly classified, and the cumulative distributions of the two groups resulting from sorting are clearly different. Hence, PLS1 regression models using simple measurements on trees and logs seems potentially useful for predictions of MOE and MOR without the use of advanced technical equipment.
Sammendrag
A quantitative multiplex real-time PCR procedure was developed to monitor the dynamics in Norway spruce (Heterobasidion annosum) pathosystem. The assay reliably detected down to 1 pg of H. annosum DNA and 1 ng of host DNA in multiplex conditions. As a comparative method for quantifying fungal colonization,we applied the ergosterol assay. There was a very high correlation between the results obtained with the two methods, this strengthening the credibility of both assays. The advantages and disadvantages of these assays are discussed.
Forfattere
Halvor Torgersen Torstein LislandSammendrag
No abstract has been registered
Forfattere
Toril Drabløs Eldhuset Arne SandnesSammendrag
No abstract has been registered
Sammendrag
No abstract has been registered