DIFFERENCE OF INVASION BEHAVIOR BETWEEN 2 CLIMAX SPECIES, CASTANOPSIS-CUSPIDATA VAR SIEBOLDII AND MECHILUS-THUNBERGII, ON LAVA FLOWS ON MIYAKEJIMA, JAPAN

The invasion behavior of two climax species, Machilus thunbergii Sieb. et Zucc. and Castanopsis cuspidata (Thunb.) Schottky var. sieboldii ( Makino) Nakai, was studied on the 1874 and 1962 lava flows on Miyakeji ma, Japan. On the 1962 lava, zoochorous M. thunbergii appeared almost only under crowns of pioneering Alnus sieboldiana Matsum, while boloch orous C. cuspidata var. sieboldii occurred only along the borders of t he lava. The three species, A. sieboldiana, M. thunbergii and C. cuspi data var. sieboldii, corresponded, in order, to the temporal sequence of invasion in the boundary forest and the spatial sequence from margi n to center on the 1962 lava. Seed or fruit dispersion is important in primary succession in the case of large disturbances.