Increment and biomass in 26- to 91-year-old European aspen and some practical implications

Abstract

Growth data were collected from 38 stands of European aspen ( Populus tremula L.) growing on forest land in Sweden. The stands ranged in latitude from 56 to 65°N. The mean age of European aspen was 46 years (range 26–91), the mean stand density 1246 stems ha −1 (range 245–3866), and the mean diameter at breast height (over bark) 20 cm (range 11– 36 cm ). Soil types in the aspen stands were divided into five groups: sandy–silty till (14 stands), light clay till (6), fine sand (5), light clay (4) and sandy till (3). Soil types represented by only one or two stands were not included in the analysis. No statistically significant differences in site index were found between the five soil-type groups in aspen stands. The mean total standing dry weight above stump level ( ≈200 mm ) for aspens was 148 tonnes ha −1 with a range of 28– 501 tonnes ha −1 . In addition to estimating conventional dry weights of trees and tree components, specific leaf area, total surface area and LAI, among other measures, were estimated. A practical implication for management of aspen stands for biofuel production is to cut the aspen after 10–20 year-rotation. Otherwise the stand could be thinned for pulpwood and timber production and the removal is used for biofuel.