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.
2008
Abstract
No abstract has been registered
Authors
Peder Gjerdrum Anna BarszczAbstract
The present research concerned selected characteristics of knottiness of large-dimensioned spruce timber (of trees with the minimum breast-height diameter of 40 cm over bark) from three stands, over one hundred years old, located in south-eastern Norway. Fourteen sample trees were felled and measured, and knots which occurred in them were classified into three categories of healthiness and three categories of tightness with the surrounding wood. Sound and tight knots were dominant in the timber under analysis. All categories varied significantly in relation to average diameters, relative diameters (related to stem thickness at the points where the knots occurred) and the relative height of location along merchantable boles. The researches analysed the significance of relations of diameters or relative diameters of knots with the relative height of their location along merchantable boles...
Authors
Petter Nilsen Line Tau StrandAbstract
No abstract has been registered
Authors
Peder Gjerdrum Mauro BernabeiAbstract
The grain direction along an arbitrary radius is known to change at a constant rate during the life-span of a tree. A wide variety of professions involve in analysing and understanding GA, included searching new technology for automated detection and significance for wood application. The objective of the study presented in this paper has been to identify a joint, three-dimensional model for grain angle in stems of Norway spruce. Five possibly large spruce trees, DBH at least 40 cm and height ca. 30 m, were sampled near Ås, Norway. 10 cm thick transverse discs were extracted at intervals of ca 5 m along the stem, split through the pith along the north-south diameter with a blunt knife, and grain angle and cambial age observed at regular intervals of 15 mm along the north radius. Pith observation was set to zero; left-handed (clock-wise) angles were denoted as positive, and vice versa. A The grain direction along an arbitrary radius is known to change at a constant rate during the life-span of a tree. A wide variety of professions involve in analysing and understanding GA, included searching new technology for automated detection and significance for wood application...
Abstract
No abstract has been registered
Authors
Harald Kvaalen Øystein JohnsenAbstract
It has been shown previously that height growth and bud phenology are influenced by the temperature during zygotic embryogenesis in Picea abies.To test whether this phenomenon operates within individual plants, clones produced through somatic embryogenesis were used. Seeds were from a full-sib family produced in both a cold (outdoor) and a warm (inside a glasshouse) environment. Embryogenic clones derived from mature zygotic embryos from both crossing environments were cultured at 18, 23 and 28 during the proliferation and embryo maturation steps.After the second growing season in a glasshouse, plants from the warm seed production environment were taller and had significantly later bud set. For the first time, it is also shown that plants are influenced by the in vitro temperature during somatic embryo development. The warmer the temperature, the later the plants formed terminal buds. The differences were similar to those produced by a provenance separation of 4-6 degrees of latitude.The results indicate that there exists a mechanism in P. abies that operates during embryo development and adjusts the timing of bud set in accordance with the temperature conditions in which the mother tree lives. This in turn counteracts negative effects of gene flow among populations located along altitudinal and latitudinal gradients.
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No abstract has been registered
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Abstract
No abstract has been registered