Phytosociological studies on forest vegetation in western Kyushu, Japan V. Natural forests of Castanopsis cuspidata and Machilus thunbergnii in regions south of Tsushima

Seventy-two samples from laurel-leaved forests of western Kyushu (excluding Tsushima), Japan, were studied phytosociolically by a Bray-and-Curtis ordination method. A composite stand was used as the first end point that represents a community on low-altitude mesic habitat. The constructed two-dimensional space represents a vegetation continuum ranging from low to high altitudes and from coastal to inland areas (Figs. 3,5 and 6). Distribution patterns of the component species were studied by plotting their occurrences on the sample position on the constructed space. No species were identical in distribution pattern, but nine groups of species were roughly recognized, which have characteristic pattern on the space. Based on the species groups recognized, the community-types represented by the three end stands were identifiable, according to the terminology of the Zurich-Montpellier tradition, as Arisaemo ringens-Machiletum thunbergii on coastal mesic habitats, Symploco glaucae-Castanopsietum sieboldii in low and middle altitudes of inland areas and Castanopsis cuspidata-Distylium racemosum community on higher altitudes of inland. Their species composition varies with each other through the intermediate stands