都市域の樹林地および樹林地を取り巻く空間の環境条件と鳥類群集との関係

Abstract

We examined relationship between bird species richness in urban woodlots and the conditions of matrix areas surrounding the woodlots as a case study. We surveyed bird communities and vegetation structures in 10 woodlots (2.26 - 2.78 ha) and 64 points in their matrix areas in Tokyo Metropolis during both wintering and breeding seasons in 2006. We measured area, latitude, and longitude of each woodlot by GIS, and estimated quality of the matrix areas surrounding each woodlot, using land cover ratios in 500 m and NDVI in 2,500 m buffers of each woodlot calculated from aerial photos and EOS-Terra/ASTER satellite imagery. We constructed multiple regression models explaining bird species richness in woodlots, using woodlot area, latitude, longitude, matrix land cover ratio, and NDVI, and that in matrix areas, using latitude, longitude, and land cover ratio. According to the models, it was suggested that open water in matrix areas influenced positively on migrant bird species richness in wintering season, and that agricultural and grassy land cover in matrix areas influenced positively on resident bird species richness in breeding season. In matrix areas, it was suggested that the amount of wood cover influenced positively on resident bird species richness in both seasons.