森林科学

In order to control the dynamics of mixed forests in the mountainous cool-temperate region in central Kyushu, the forest structure of two stands at different stages of forest succession was investigated. From comparisons of forest structure, in dices for forest conservation were discussed with regard to extent, frequency and intensity of disturbance. 58 species were found and classified into four groups according to ranking of their relative coverage in the two stands at the each stage of succession. This ranking of species corresponded with species characteristics of appearance in the temporal series of the forest succession. This correlation was confirmed by size distribution analysis, and was thought to be a useful index for forest conservation in terms of control of the frequency of disturbance. Further, this ranking was thought to reflect the difference in the light environment of the habitats, and to be a possible control of the extent of disturbance. From the analysis of clump structure, species were classified into three types by their sprouting characteristics as follows; 1) species which can maintain their population by natural sprouting under the condition without any disturbance, 2) species which can recover their population by sprouting after disturbance, 3) species which can not sprout under any conditions and which recover only by seedlings. These categories were thought to be helpful in the control of the intensity of disturbance which regulates the degree of destruction of conditions for forest recovery.