三峡工程及水位变化对坝区鼠密度的影响

目的 了解三峡大坝水位变化对当地鼠类生存的影响,为鼠传播疾病的控制提供依据.方法在三峡坝区,选择位于坝区上下游的银杏沱村、龙潭坪村、石板村、沙坪村为调查点,采用Elton夹夜法,每次连续捕鼠2 d.收集鼠夹,计算鼠密度并鉴定鼠种,比较室内外鼠种、鼠密度及水库156 m蓄水前后鼠密度变化,分析蓄水及清库对坝区鼠密度的影响.结果共捕鼠678只,其中室内517只,室外161.室内黄胸鼠为优势鼠种,共捕获189只,占36.49%(189/517);室外黑线姬鼠为优势鼠种,共捕获91只,占56.88%(91/161);室内外鼠种构成比较差异有统计学意义(x2=678.00,P＜0.01).共布有效夹8036夹次,平均鼠密度为8.44%(678/8036),其中室内鼠密度为14.44%(517/3581),室外鼠密度为3.61%(161/4455),室内外鼠密度比较差异有统计学意义(x2=301.04,P＜0.01).大坝蓄水至156 m后鼠密度(10%,513/5132)明显高于蓄水前(5.68%,165/2904),蓄水前后鼠密度比较差异有统计学意义(x2=44.68,P＜0.01).坝区上游鼠密度随蓄水的升高变化明显,在2007年5月至2008年5月,鼠密度形成一个高位平台,依次为12.25%(80/653)、13.16%(90/684)、12.95%(90/695),到下一次清库后有所下降(8.38%,28/334).结论三峡大坝工程及水库蓄水后的水位变化改变了鼠类的生存环境,致当地的鼠密度发生了改变,今后应加强对坝区鼠类的监测,防止鼠传播疾病的局部爆发或流行.

Effects of the Three Gorges project and change of water level on local mouse density

Objective To study the impacts of the Three Gorges dam and change of water level on the survival of the local rodents, and to provide scientific basis to control the outbreak of rodent-borne diseases.Methods Four villages located around the Three Gorges dam were selected in the study. The mouse populations by using Elton night trapping method was monitored. Metallic spring traps were set for two consecutive nights. The mouse density and identified the mouse species was calculated. The mouse species indoor and outdoor, as well as the mouse density indoor and outdoor were compared. The impacts of water level in the dam and cleaning work on local mouse density were also analyzed. Results A total of 678 mice were caught in this study, 517 were caught indoor and 161 outdoor. Indoor dominant species was flavipectus; accounting for 36.49%(189/517), while outdoor was apodemus, reaching 56.88% (91/161). For mouse species, there was a significant difference between indoor and outdoor(x2 = 678.00, P ＜ 0.01 ). The average mouse density was 8.44%(678/8036) in trap nights. Indoor mouse density reached 14.44%(517/3581 ), which was significantly higher than that of outdoor(3.61%, 161/4455 ).For mouse density, there was a significant difference between indoor and outdoor(x2 = 301.04, P ＜ 0.01 ). When the water level was up to 156 m, mouse density reached 10%(513/5132), which was higher than that of before (5.68%, 165/2904). There was a significant difference in mouse density before and after reserving water (x2 = 44.68, P ＜ 0.01 ). With the change of water level, upstream mouse density formed a high platform from May 2007 to May 2008, followed by 12.25%(80/653), 13.16%(90/684), 12.95%(90/695), and decreased to 8.38%(28/334) after cleaning of the dam. Conclusions The Three Gorges dam and change of water level actually alter the survival environment of the local mouse, and affect local mouse density and mouse species. These may lead to local outbreak or epidemic of rodent-borne diseases.