宍道湖周辺のため池におけるヒツジグサの定着に及ぼす水生動物の影響

In 9 selected irrigation ponds located around Lake Shinji, Shimane Prefecture, Japan, effect of aquatic animals on the establishment of Nymphaea tetragona, a floating-leaved aquatic macrophyte, was investigated during May-October 1991, by using a pair of pots with and without net of 1 cm mesh size. In result, differences in numbers of plants and leaves were found between the pots in each pond. The interference of aquatic animals on the establishment of N. tetragona was significant in some ponds but not in other, and the significance of biotic disturbance on the distribution of this species was confirmed.
Key words: aquatic plant, biotic factor, distribution, disturbance, pond