洞庭湖洲滩开沟沥水控制钉螺繁殖的研究

目的 目的 评价洞庭湖区有螺洲滩实施开沟沥水工程后对钉螺孳生繁殖的影响。方法 方法 2009年11月-2012年11月， 选择位于东洞庭湖区的岳阳监狱和君山区有螺外洲滩， 分别设为干预区和对照区2组研究现场观察区。在干预区洲滩实施开沟沥水工程， 采用挖掘机开挖 “井” 字沟， 观察该工程对洲滩土壤含水量和相对地下水位、 以及对钉螺孳生繁殖的影响。对照区洲滩不采取任何措施。结果 结果 开沟沥水工程实施前， 2组观察区在枯水期不同高程的洲滩土壤平均含水量均在35.56%左右。工程实施后， 干预区洲滩土壤平均含水量26.53%， 而对照区则为35.56%， 两者差异有统计学意义 （F = 6.53，P < 0.05）； 干预区不同高程相对地下水位明显低于对照区， 差异有统计学意义 （χ2= 33.33，P < 0.05）。工程实施前， 干预区和对照区钉螺自然死亡率分别0.98%和0.89%， 差异无统计学意义 （P > 0.05）； 工程实施后的2012年干预区未再查见钉螺和幼螺，而对照区活螺平均密度和幼螺则仍分别为29.37只/0.1 m2和 213±108.45只/0.1 m2。结论 结论 在湖区有螺洲滩开沟可迅速沥干洲滩积水， 显著降低洲滩土壤的含水量， 改变钉螺繁殖和孳生的生态条件， 从而控制钉螺的孳生繁殖。

Effect of ditching for drain on control of Oncomelania hupensis snail in beaches of Dongting Lake

Objective Objective To evaluate the effect of ditching for drain on the control of the breed of Oncomelania hupensis snailsin beaches of Dongting Lake. Methods Methods From November，2009 to November，2012，an O. hupensis snail infested beach of theYueyang jail and an O. hupensis snail infested beach of Junshan District were selected as research fields in the eastern DongtingLake area，and the former，as the intervention field，was performed with the ditching for drain by excavators and the latter，asthe control field，was not. Results Results Before the project implemented，the average soil moisture contents on the beaches in dryseasons of the two fields were both about 35.56%. After the project implemented，in the intervention field，the average soil mois?ture content was 26.53% which was significantly lower than that（35.56%）in the control field（F = 6.53，P < 0.05） . The under?ground water levels in different heights in the intervention field were lower than those in the control field（ χ2= 33.33，P <0.05） . Before the project implemented，the natural death rates of the snails were 0.98% and 0.89% in the two research fields re?spectively（P > 0.05），and after the project implemented（in 2012），no adult and young snails were found in the interventionalfield，but in the control field，the average densities of living snails and young snails were 29.37 snails/0.1 m2and 213±108.45snails/0.1 m2respectively. Conclusion Conclusion The intervention of ditching for drain can decrease the soil moisture contents quicklyand change the ecological condition， therefore， can control the breed of O. hupensis snails in the beaches of Dongting Lake.