神奈川県大磯丘陵の里山におけるチョウ類群集の種多様性

抄録

Species diversity of butterfly assemblages was investigated using the transect count method at two sites, Tsuchiya and Ikusawa areas, of the Satoyama in a broad sense consisting of mixtures of woodlands, farmlands, and settlements in the Oiso Hills, southern Kanagawa Prefecture, central Japan twice a month from April to October, 2009. As a result, a total of 1,776 individuals belonging to 54 species of butterflies was observed in the two sites. Species richness and the mean density (count/km) of butterflies observed and species diversity (1-λ) were similar to each other at two sites; 50 and 47 spp, 42.1 and 42.5, and 0.96 and 0.97 at Tsuchiya and Ikusawa areas, respectively. However, some typical coppice species were recorded only from Tsuchiya area, while evergreen broad-leaved forest species and mountain stream species were abundantly found in the Ikusawa area. It is considered that the results reflect the difference in land use including coppice management between two sites: there were well managed coppice remnants in parks and cemeteries in the Tsuchiya area, while abandoned coppices have changed into evergreen broad-leaved forests along a mountain stream in the Ikusawa area.