Abstract
In urban areas, it is important to conserve biodiversity because biodiversity is the basis of the ecosystem services. This study focused on cicadas because they serve as an indicator of the environmental conditions. We aim to clarify cicada distribution in urban areas and the environmental factors that affect its population and distribution. By using a method for counting the cast-off skins of the cicadas, we recorded cicada population three times during the summer of 2011 at 49 forest sites in Tokyo metropolis. In addition, we recorded environmental factors through field surveys and satellite imagery analysis. The species composition of cicada was analyzed using the Nestedness Temperature Calculator program, and the relationship between the cicada population and environmental factors was analyzed using a generalized linear mixed model (GLMM). As a result, six cicada species and the cast-off skins of five species were found in the studied sites. The species composition of cicada has a nested structure, with one species dominating many sites. The common factors having a statistically significant influence on the cicada population were soil moisture, soil hardness, leaf coverage in the middle layer, height of shrub layer, and average breast height diameter of trees, which were obtained using a GLMM. Among these factors, we also obtained the characteristic factor affecting each cicada species.
