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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.

2001

Abstract

An accumulating body of research identifies the importance of landscape structure for a wide range of countryside interests. Landscape structure reflects the results of policies and practices, and is well-suited as a target for management actions. New landscape metrics represent a potential for indicator-based management, provided such metrics relate consistently to the landscape values of interest. In this paper we propose that aspects of landscape structure, specifically heterogeneity, may be related to landscape-based values such as biodiversity, cultural heritage and human appreciation. Birds and vascular plants correlated well with our index for the heterogeneity of land types, whereas insects did not. Occurrence of prehistoric graves was also associated with land type heterogeneity, though other types of cultural remains were not. Landscape experience seems to be associated with the heterogeneity of landscape space rather than heterogeneity of land types. Different aspects of heterogeneity, scale, and variation over time all contribute to explain how our measures of landscape-based values vary in their relationship to landscape heterogeneity. Successful integration between disciplines in landscape studies depends on having a common operational framework, a shared theoretical basis, and a harmonised approach to data collection.

Abstract

Genetic associations between initiation of embryogenic tissue (ET) and susceptibility to the phytopathogenic fungi Ceratocystis polonica (Siem.) C. Moreau and Heterobasidion annosum (Fr.) Bref. in Norway spruce have been studied by initiating ET from zygotic embryos of mature seeds collected from 19 clones tested for susceptibility to the pathogens in a clonal field trial.Initiation frequencies varied significantly among clones (families), ranging from 12 to 56%. The family variance component accounted for more than 40% of the total variance in initiation frequency of ET. The estimates of broad-sense heritability of fungus susceptibility of the clones ranged from 0.12 for length of phloem necrosis after low-density inoculation with H. annosum to 0.55 for blue-stained sapwood after mass inoculation with C. polonica.None of the susceptibility measures showed any phenotypic correlation with initiation of embryogenic tissue. Genetic correlations and their standard errors were estimated by bootstrapping. Two measures of fungal susceptibility correlated genetically with initiation of ET; estimated at 0.58 for lesion length after inoculation with C. polonica and 0.29 for H. annosum lesion length. A better measure of susceptibility, blue-stained sapwood following inoculation with C. polonica, was not correlated with initiation of ET.

Abstract

Sawmill recovery might be improved by pre-conversion sorting of logs to obtain more homogenous timber quality suitable for specified products. To enhance the knowledge of factors influencing timber quality, 670 spruce trees from 11 mature stands were observed during harvesting and timber processing. By means of factor analysis several knot and resin pocket properties were reduced to two principal components, one representing the knots and another for resin pockets. The number of independent variables are not easily reduced, leaving a possibility of applying several of the characteristics of the logs, the trees and of the stands in finding an efficient log sorting algorithm.