洞庭湖区东方田鼠2007年暴发成灾的原因剖析

Analysis on Causes of Population Outbreak of Microtus fortis in Dongting Lake Region in 2007

2007年东方田鼠种群暴发是其种群数量自然波动到达高峰期的体现。洞庭湖湖泊泥沙淤积导致的沼泽化是其成灾的主要基础;而围湖造田、围湖灭螺和滥捕天敌乃是湖区东方田鼠上世纪70年代开始形成严重危害的直接原因;近期三峡工程和退田还湖工程又进一步加强了东方田鼠的暴发危害。因此必须高度关注东方田鼠种群的未来发展趋势。

The outbreak of Microtus fortis in Dongting Lake region in 2007 showed that the population was in one peak of multi-annual population fluctuation. The outbreak was predicted according the understanding to the population fluctuation and high population density in its beach and island habitat in the Dongting Lake. Historically,the withering of the lake and the enlarging of lake beach and island caused by silt was the fundamental reason of the vole becoming disaster,beanse it provided more favourite habitat for M. fortis and led the expanding of M. fortis. And the reclaiming land from the lake and building cofferdam to kill oncomelania had accelerated the course of the expanding of the vole＇ population and becoming harm finally from 1970＇s. And now the Three-Gorge Engineering and converting the cropland of some polder back into lake were also advantagous to the vole population. It was suggested to pay more attention to the vole＇s population fluctuation.