Douglasie - eine Bauholzart mit Zukunft : Jahrestagung des Nordwestdeutschen Forstvereins

2000

S. 728-732

zahlr. Lit. Ang.

Unselbständiges Werk

200072586

According to the latest forest inventory in Germany the total area of Douglas fir plantations was approximately 134.00 hectares. At present approximately 80 % of these stands are in the first and in the second age classes (less than 40 years old). Therefore the majority of the growing stock is composed of small sized timber. As a result of the present situation in the timber market the utilization of small sized Douglas fir timber from thinned stands is problematic. A decisive criteria for the evaluation of small sized Douglas fir timber is a small proportion of heartwood, at least as far as the utilization in the pulp and paper industry is concerned. However, with increased attention being paid to reduce the use of chemical wood preservatives in the construction of houses and horticulture, the natural durability of heartwood of Douglas fir is particulary interesting. In this paper a spectrum of utilization possibilities of the Douglas fir timber are shown. The advantages of the physical and mechanical properties of the Douglas-fir timber are stressed. Furthermore the effect of the juvenile wood on the timber quality is discussed. In the next decades Douglas fir will become an important construction timber in Germany. The silvicultural management of Douglas fir stands should lead to high quality timber production. Spacing greatly affects the wood quality of Douglas fir and it especially affects knottiness. To produce a high value timber timely pruning of the Douglas fir is an imperative. At present time there are no wood quality investigation results about Douglas fir grown under closed canopy or in mixed stands. Therefore, from the wood technological point of view further investigations on wood quality of Douglas fir grown under such conditions are necessary.