ため池における水質と浮葉植物の繁茂状況の関係

抄録

In order to elucidate the factors controlling the coverage and species of floating-leaved plants and the influence of the plants on the water quality, we heve investigated land use in the watershed, water quality and plant coverage in 20 irrigation ponds in the Kamo Hight, Hiroshima Prefecture. Both water depth and surface area were the dominant factors controlling the area of coverage of the plants. In addition, nutrient concentration in the water significantly affects the species. The percentage coverage potentially influences not only the seasonal changes in chlorophyll a concentration, UV absorbance : DOC ratio and chlorophyll a : COD ratio, but also the ratio of chlorophyll a to limiting nutrient. This percentage coverage may also affect the nutrient concentration in the water, particularly nitrogen, possibly through its uptake from the water.