Survival, growth, and growth allocation of planted Scots pine trees after different levels of biomass removal in clear-felling

摘要

A great concern in forestry today is whether whole-tree harvesting influences site productivity and whether it is consistent with the principle of sustainable use of forest resources. To evaluate this a randomised field experiment established 24 years ago in Scots pine (Pinus sylvestris L.) in southern Sweden was used. Treatments were conventional stem harvest (CH), whole-tree harvest (WTH), and branch and stem harvest (BSH). Seedling survival was unaffected by treatments. The total basal area over bark at breast height (1.3 m, m(2) ha(-1)) was significantly reduced following WTH from the 15th year after planting. Sample trees on CH plots produced 20% more wood biomass than WTH and BSH plots, while biomass produced within the crown was unaffected by treatment. Height growth was greater for sample trees on CH plots during the last year of measurement, while basal area and volume under bark were larger from the 12th year onwards when compared with the WTH treatment. BSH showed a decreased basal area growth under bark during the two 4-year-periods, 13-16 and 17-20 years after planting, and a decreased volume growth under bark from year 9 onwards in comparison with CH.