The geographical distribution of Persea thunbergii (Machilus thunbergii)-type forest was studied in relation to ecological factors in the Japanese Archipelago from Yakushima to Tohoku district. Persea-type forest was defined as lucidophyllous forest dominated by canopy trees of P. thunbergii, Elaeocarpus sylvestris var. ellipticus, Cinnamomum japonicum, C. camphora, Daphniphyllum teijsmannii, Neolitsea sericea, Litsea lancifolia, Ilex integra, I. rotunda, Osmanthus insularis, Prunus zippeliana, Turpinia ternata, Podocarpus macrophyllus, Ardisia sieboldii, and Ternstroemia gymnanthera. These species have endozoochorous seed dispersal by birds and are highly resistant to the action of sea wind with salt. Persea-type forest studied in 340 localities was located almost exclusively in narrow coastal areas, 300 m from the nearest coastline, as a preclimax in littoral areas affected by the northwestern winter monsoon, typhoons or severe sea wind. The forest was divided into 14 types according to the dominant canopy trees, of which P. thunbergii-dominated forest was distributed most abundantly in 246 localities. E. sylvestris var. ellipticus-dominated forest was distributed concentrically in coastal areas from the Kii Channel to the Seto Inland Sea on the Shikoku side, where P. thunbergii-dominated forest was rare. Forests dominated by C. japonicum, D. teijsmannii, N. sericea and I. integra were situated between P. thunbergii-dominated forest and the sea.

抄録全体を表示