关键词: 森林蒸散, 理论, 方法

Abstract: During 1980—1986 the resource of Japanese eel larva of the Changjiang River Estuary inShan-ghai region was investigated.The larva appeared in mid-February and disappeared in mid-May each year.The peak period of the larva emergence lasted about 30—40 days.The numberof larva in the northern branch of the river was larger than in the southern branch.The hum-bear of the larva around the eastern shore of the Chongming Island was greater than the westernshore.Recently the production of the larva decreased gradually perhaps because of the waterpollution of the river and over-fishing(including the falling-sea eel parents).Rake-nets,Pair-tow-nets and stable nets are usually used to catch the larva.The average catch-mortality withthe stable net was significantly higher than with the others(p<0.01).Suggestions were givenon how to rationally exploit this renewable resource and protect it from over-fishing.

Key words: Forest evapotranspiration, Theory, Method