Abstract
We evaluated spatial variations of habitat suitability of nine aquatic insects in the Natori River basin, Northeast Japan quantitatively combining dual approaches of using Habitat Suitability Index (HSI) model analysis and hydrothermal simulation model. We also developed a new index of the Weighted Usable Ratio (WUR) for evaluating the overall habitat suitability throughout the catchment for each species. The results of spatial distributions of HSI showed species-specific patterns such as wide distribution of digit grids with high HSI throughout the catchment in habitat generalists (e.g., Baetis, WUR=0.55) while the constrained distribution in habitat specialists (e.g., Limnocentropus insolitus, WUR=0.06). Overall, the spatial variation of HSI showed good consistency with the empirical habitat distributions, supporting the accuracy of our model approach.
