ZLV Online

Abstrakt

Silver birch is a common tree species in Czech forests. It is, however, still considered by some forestry practitioners a weed species though it has been listed as soil-improving and stabilizing component of forest stands since 1996. Silver birch grows naturally on many forested sites from lowlands to foothills. This study focused on biomass production of 22-year-old birch forest stand on nutrient-poor, gleyic sites. Six experimental plots were established to investigate stand characteristics such as number of trees, DBH, basal area, standing volume and weight of below-ground and above-ground biomass. Both above- and below-ground biomass were divided into particular components, such as leaves, branches, bark of stem, wood of stem, bark of stump, wood of stump, fine roots (up to 1cm), medium roots (up to 5 cm) and coarse roots (up to 10 cm). The components were dried and analyzed to investigate biomass nutrient concentrations and pools. The 62% of the total biomass was over-bark stem (95–139 t.ha-1), 19% were stumps with roots (27–45 t.ha-1), and 19% were branches with leaves (29–45 t.ha-1). The most nutrient-rich components were leaves and branches, the least one was wood of stem. The greatest nutrient pool were branches, the least one were leaves. Below-ground nutrient pool assessed using allometric equations was 15–17% of the total biomass nutrient pool. As for the management implications, full-tree removal should be avoided in the birch stands on nutrient-poor gleyic sites over the rotation.