Abstract

The growth and production in shelter stands of Norway spruce (Picea abies (L.) Karst.) and birches (Betula pendula Roth and Betula pubescens Ehrh.) were studied at nine areas in southern and middle Sweden (Lat. 56 – 60° N.). The spruces and birches were 25 (20 – 32) years old. Before the study was established, the stands evaluated were dense with planted spruces under self-generated birches. A birch shelter with 500 stems per hectare was created. The shelter was cut after ten years. In one stand per locality, 100 birches were left at harvesting time for further growth and development of timber quality. The MAI 20 years after treatment for pure spruce stands was 4.71 and 4.38 m3 ha-1 year-1 for spruces growing in mixed stands. The MAI for shelter birches was 4.13 m3 ha-1 year-1 and then the MAI for spruces and birches in mixed stands was 8.1 m3 ha-1 year-1. When the study was established the volume and biomass weight of the harvested birches was 107 m3 ha-1 or 84 ton d.w. ha-1 when all birches was removed and 75 m3 ha-1 or 44 ton d.w. ha-1 when a shelter of 500 birches ha-1 was left. The harvested wood could be used as biofuel. Timber could be harvested in stands where 50-100 birches ha-1 in the shelter are left. Among the remaining 100 birches per hectare in shelters examined 30 years after establishment of the study the standing volume ranged between 54 and 67 m3 ha-1.

Keywords

Birch; MAI; mixed stands; Norway spruce; shelter; timber

Published in

Rapport (Institutionen för energi och teknik, SLU)
2014, number: 068
Publisher: Swedish University of Agricultural Sciences, Department of Energy and Technology

SLU Authors

• Johansson, Tord

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Permanent link to this page (URI)

https://res.slu.se/id/publ/52392