Norwegian Journal of Agricultural Sciences : silviculture for fuelwood

Abstract

Management of birch forest growing in Nordic countries is presented. Biological characteristics of the two birch species: silver birch (Betula pendula Roth) and pubesccnt birch (Betula pubescens Ehrh.) are described. Natural regeneration of birch on forest land is the common way to establish birch forest. Planting is too risky as moose, roe deer and hare very frequently browse the plants. Birch is a light demanding species and strong competition causes the plant to react. lf the competition is too strong, the percentage green crown decreases below 50 % of the tree height. Then the growth rate is decreased and a cleaning or thinning operation later on does not repair the darnage. Therefore birch forest must be intensively managed from the young stand stage. Two to three thinning operations are necessary to maintain the growth rate and to manage an even-aged stand containing large-diameter stems with high wood quality. On a fertile forest site silver birch has a total yield production of 270 m' ha:' and pubescent birch 150 m1 ha' based on a rotation period of 50-70 years. Some recommendations about management of sprout forest stands are given. Recommendations are given on silvicultural methods for afforestation on abandoned farmland. Total yield production for silver birch forest growing on farmland is 350 m^3 ha^4 and 200 m^3 ha^4 for pubescent birch based on a rotation period of 40-60 years. Fuelwood production of naturally regenerated birch on abandoned farmland is discussed. An annual mean yield of biomass production of at least 5-6 ton d.w. ha' is possible.