Abstract

Altogether 1080 two-year-old silver birch (Betula pendula Roth) were planted in groups of 36 plants at a spacing of 20 x 20 cm in spring 1981 on a nursery field at lat. 60° 15’ N. and long. 16° 00’ E. In spring 1984 all plants were out cut with 10 cm high stumps and light screens were arranged on the stump groups. Relative irradiance (RI) 5, 10, 25. 50, 75 and 100 % of full sunlight were used. After five growing seasons after cutting, all stumps exposed to 5 or 10 % light intensity were dead and 64-94 % of stumps exposed to 25- 100 % RI were alive. 1.3-1.4 sprouts per living stump were living five years after cutting. The mean height of sprouts was highest on stumps exposed to 100 % light. Also dry weights of leaves and sprouts, number of leaves per sprout, and leaf area were highest on stumps exposed to full sunlight. Stumps producing only one sprout five years after cutting have higher height and dry weight values than stumps with more sprouts. The biomass production per hectare and year for silver birch sprout at a spacing of 0.2 m and with 90 % survival was calculated as 5.4 tonnes. The biomass of leaves was 8.1 tonnes/ha/year five years after cutting.

Keywords

Betula pendula Roth; biomass production; carbohydrate; long-term effect; relative irradiance; silver birch; stump; sprout; sprouting

Published in

Scandinavian Journal of Forest Research
1991, Volume: 6, number: 1-4, pages: 509-518

SLU Authors

• Johansson, Tord

  • Department of Forest Yield Research, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1080/02827589109382687

Permanent link to this page (URI)

https://res.slu.se/id/publ/68916