霧島山系白鳥川上流域に広がる照葉樹林の植生学的研究

抄録

The forest in the upper reaches of the Shiratori River in the Kirishima mountain system, Miyazaki prefecture is one of the largest and best preserved lucidophyllous forests in Japan. The vegetation of both the closed canopy stands (mature phase) and the canopy gap stands (gap phase) in the forest was studied in order to clarity the difference of species composition and species richness between the two phases. The mature phase was differentiated by the presence of 17 species (Bulbophyllum drymoglossum, Davallia mariesii, Selanginella involvens, Lepisorus onoei, Asplenium wilfordii, Lemmaphyllum microphyllum and others). The gap phase was differentiated by the presence of 52 species (Akebia trifoliata ,Callicarpa mollis, Mallotus japonicus, Zanthoxylum ailanthoides ,Actinidia polygama, Rubus palmatus and others) .All of the differentia lspecies of the mature phase were epiphytes which were elements of lucidophyllous forest. 44 species in the differential species of the gap phase were summergreen trees, summergreen shrubs, summergreen climbers, perennial herbs and others which composed the Rosetea multiflorae ,the Fico-Mallotetalia ,and the Quercetalia serrate-grosserratae .The mean number of occurring species in the mature phase and the gap phase is 40 and 67, respectively. It has become clear that vegetation of gaps contributes to species richness in the lucidophyllous forest.