Study on understanding of disturbance regime and mechanisms of tree species coexistence for sub-boreal and sub-alpine evergreen coniferous forests.

为了了解亚北方和亚高山森林中物种的共存情况，利用半球面照片估计的天空因子数据集，采用局部加权回归平滑方法建立了量化每一株树木光照状况的新方法。测定了两种杨树的茎粗生长率。在亚高山森林中随着间接天空因子的增加。另一方面，光照条件对亚高山亚高山林下落叶层树干生长格局的影响小于亚高山林种。

To understand species coexistence in sub-boreal and sub-alpine forests, the new methods quantifying light condition of each individual tree were developed by a locally weightedregression smoothing method with the data set of the sky factors, which were estimatedusing hemispherical photographs. The growth rates of the stem diameter for the twoAbiesspp. increased with the indirect sky factor in the sub-alpine forests. On the other hand, the effect of the light conditions on the stem growth patterns of the understory in asub-boreal forest was smaller than those for the species in the sub-alpine forests.