自己間引き林分におけるダケカンバ個体の成長パターン

北海道大学低温科学研究所

低温科学

We analyzed the tree-ring widths of 74 trees of Betula ermanii in a self-thinning stand. The frequency distribution of tree age was a bell-shaped pattern with a peak at 25-years old. For most trees,the tree-ring width tended to decrease annually,and this trend was more conspicuous for younger trees. The tree-ring width in the most recent five years tended to be greater for larger trees. Climatic factors (monthly mean temperature and precipitation) during the growing season hardly affected the tree-ring widths of most trees. These results showed that the growth rate was faster for the trees that recruited earlier because of strong competition among trees in this self-thinning stand, and that climatic factors hardly affected tree growth.