[Текст] / E. Agestam, P. Eco, U. Johansson ; Swedish University of Agricultural Sciences Faculty of Forestry. - Uppsala : Swedish University of Agricultural Sciences, 1998. - 17 с. : Figures + Tables. - (Studia Forestalia Suecica / Swedish University of Agricultural Sciences, Faculty of Forestry, ISSN 0039-3150 ; 204). - Библиогр: p. 15-17%ISBN 91-576-5555-3. - 4-00 р.
Аннотация: Timber quality in Scots pine (Pinus sylvestris L.) stands in Sweden has deteriorated during the 20th century. A possible cause of this is the increasing proportion of timber that originates in planted stands. Two naturally regenerated and two planted pine stands, of the same genetic origin, were compared. The planted stands were established as spacing experiments (1.25 x 1.25-2.5 x 2.5 m) at Tonnersjoheden Experimental Forest (lat. 56 grades 42'N, long, 13 grades 06'E, alt 60 m). Volume growth and timber quality, i.e. taper, crookednees, number of branches, branch thickness, branch angle, crown size, occurrence of spike knots and damage were compared. The quality of dominant and co-dominant trees was higher in the naturally regenerated stands than in the planted stands. Of the planted trees, only 25% were straight, compared with 86% of naturally regenerated trees. In the planted stands, the mean diameter of the thickest branch below 2m was 23 mm, compared to 15mm inthe naturally regenerated stands. Timber quality and
planting density were also positively correlated, quality being very poor at the widest spacings. Volume growth at initial spacings of 1.75 x 1.75m and denser was estimated to be 5-10% higher than that in the naturally regenerated stands.
Доп.точки доступа: Johansson, U.; Eco, P.
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