Abstract
We investigated the ecological distribution of seven evergreen Quercus species in southern and eastern Kyushu, Japan by analyzing previously reported vegetation data. Analysis along an elevation gradient, together with cluster analysis of species correlations, revealed two major species groups with distinct distributions: a high-elevation group comprised of Quercus acuta, Q. salicina, Q. myrsinaefolia, and Q. sessilifolia and a low-elevation group consisting of Q. gilva, Q. glauca and Q. hondae. The distribution of Q. acuta had the highest elevation range, Q. hondae the lowest, of the seven species. Q. acuta also showed a preference for upper slope topographic positions. In contrast, the occurrence of Q. sessilifolia, Q. gilva and Q. hondae was biased towards lower slopes. The occurrence of Q. sessilifolia was particularly restricted to lower slopes at lower elevation (<400m), suggesting that it is a characteristic component of riparian lowland areas. Q. salicina had the highest frequency and least pronounced site preference with respect to both elevation and topography, indicating that it is a typical generalist species. Q. glauca had no topographic preference and was grouped with pioneer and/or deciduous species in cluster analysis, suggesting that it is an early-seral or disturbance-dependent species.