伊勢湾台風4年後の吉野川の水生昆虫群集

概要

論文の詳細を見る
Before the Ise-wan Typhoon (September 1959), the Yoshino River (Nara Prefecture) had the largest standing crops of aquatic insects known in Japanese streams. However, the aquatic insect communities were destroyed considerably by the Typhoon. We studied this river in September 1963,four years after the Typhoon, and wish to report the results and to compare them with the data of TSUDA and GOSE (1953,1954), who studied this river in 1953,six years before the Typhoon. The results are summarized as follows : 1. In August 1953,six years before Ise-wan Typhoon, the standing crop of the station "Koshibe" was 32 g per 0.25m^2 in a wet sample. But in September 1963 the standing crop of this station was only 0.5g. Also the other stations had far less standing crops in 1963 than in 1953. 2. In 1953,the net-spinner's percentage ("net-spinner's percentage" means the rate of the weight of the net-spinners to the total weight of benthic insects) of the station "Koshibe" and the station "Kawaraya" were 80〜95 per cent. But in 1963,the net-spinners percentage were 42〜73 per cent, and the percentage of the creepers were more in 1963 than in 1953. 3. In 1953,among the net-spinners Parastenopsyche sauteri (Stenopsychidae) was dominant in this river. In 1963,however, Hydropsyche ulmeri (Hydropsychidae) was dominant in the same river.
1964-04-01