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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.

2000

Abstract

Coastal spruce forests of central Norway harbour a unique assemblage of epiphytic lichens and are given high priority with respect to conservation of biodiversity. To assess the historical impact of logging during the last 100-150 yrs, 31 remnant stands were studied by means of tree-ring analysis of 2199 trees and the decay stage of 1605 stumps. No stands had been clear-cut, but all had been selectively logged at least twice during the last 150 yrs. Total harvested timber volurne ranged from 65 to 409 m3ha-1 (31-124 % of present-day standing volume) and the selective logging kept standing volume low (40-200 m3ha-1) during 1890-1930. Present-day stand characteristics were strongly correlated with site productivity and topographic position within the ravine valleys. Low amounts of dead wood at sites with high historical logging activity was the only consistent relationship found after covariance of site productivity, topographic position and deciduous trees were taken into account. The results indicate that old-growth stand characteristics, such as reversed J-shaped age distributions and dead wood in advanced decay ciasses, can be obtained 100-150 yrs after intensive selective logging.

Abstract

The present investigation deals with the properties of resonance wood destined for the production of musical instruments and with the methods for the determination of resonance wood quality. At the same time there are stated the range of values for the dynamic modulus of elasticity, for the speed of sound transmission and for the density of wood. The demands regarding dimension and growth characteristics of resonance wood are explained insisting first of all on pure subjective and visual criteria. The grading rules, existing only in a few regions in Germany, show that forestry is sensitized to this high value timber assortment only to a very small extent. With the Lucchimeter measuring method (elasticity tester) and the stress wave nondestructive evaluation technique spruce (Picea abies) and fir (Abies alba) wood panels are investigated which are destined for the production of guitars. The methods used as well as the results of measurement are compared with another. Furthermore the quantity of sales of resonance wood is presented after survey at the state owned forest management in Germany. The established small quantity of existing resonance wood is attributed to the sales of resonance wood not mentioned explicitly or described in detail. All in all the amount of resonance wood is supposed to be higher.