Abstract
The effect of riparian forest on water environment was studied in the River Miyamori, Iwate prefecture, based on the data on water quality, aquatic insect communities, flowing organic matter, sediment particle distribution and chlorophyll-αon the artificial substrate. The riparian forest located in the upper and middle water regions increased the flux of flowing organic matter and the amount of organic matter in the riverbed, resulting in an increase in the number of individuals and taxa of aquatic insect. It was found that the individual number of shredder and the flux of flowing organic matter with a size of more than 3.35mm had a good correlation and the value of Shannon Diversity Index of aquatic insect was increased.
