Diversity component pattern described as α, β, γ diversity in ecological community is a key challenge for understanding biodiversity. That provides how conservation resources should be allocated among site in the region. Especially, contribution of agricultural area is had an interest for biodiversity conservation and ecosystem service management. In the Monsoon Asia, agricultural irrigation for rice farming consists of vast freshwater area. Irrigational habitat often has high species diversity, but its contribution for regional community is well known enough.

Here, we estimated contribution of aquatic species diversity in irrigation channels within the Tama river basin, central Japan.

Sampling was conducted in a mainstream and its connected tributaries, floodplains and irrigation channels as permanent aquatic area. We analyzed using additive partitioning of diversity among these habitats, plot of species composition with Non–metric Multidimensional Scaling, comparison of species accumulation curves.

In our presentation, we would report how species diversity and compositional heterogeneity distributed in irrigational area and other habitats.