鄱阳湖洲滩钉螺分布与水位变化的关系

STUDY ON RELATIONSHIP BETWEEN SNAIL DISTRIBUTION OF MARSHLAND AND CHANGES OF WATER LEVEL IN POYANG LAKE REGION

目的 探讨鄱阳湖水位变化对洲滩钉螺分布的影响,为设计生态灭螺规划提供科学依据。方法 收集既往鄱阳湖洲滩钉螺资料与水位资料进行统计分析。结果 鄱阳湖钉螺面积的94.55％分布于14-17m高程洲滩;水位变化的重要指标为洲滩水淹日数与显露日数,通常水淹日数为216-113d(中位数160d);显露日数为149-252d(中位数205d)。结论 鄱阳湖洲滩钉螺分布与水位变化密切相关,4-6月份由江西省境内5河洪水引起的洲滩水淹与显露日数比例是制约洲滩钉螺密度与分布的关键,2-5月洲滩显露有利于钉螺产卵,5月以后洲滩水淹则有利于螺卵孵化与幼螺的发育生长。因此,控制鄱阳湖水位,改变钉螺生态特性即可达到制约湖区钉螺的目标。

Objective To explore the relationship between the snail distribution in marshland and the change of water level in Poyang Lake region and provide the scientific basis for snail control ecologically. Methods The data of snails and water level which had been collected from Poyang Lake region were analysed statistically. Results The altitude scope of main snail-distribution belt was from 14 m to 16 m in grassy beach. The main indicators of water level in the marshlands were the exposure days and waterlogged days. The ranges of the former and the latter were 216-113 days and 149-252 days respectively, and the medians were 160 days and 205 days respectively, and the exposure period of the marshlands was in favor of egg-laying, meanwhile, the waterlogged was contributed to egg-hatching and development of baby snails. Conclusion The relationship of the snail distribution and water level in Poyang Lake region is very intimate. The amphibious ecological habit and characteristic of snails are influenced by the days of waterlog and exposure. Hence by taking the advantage of this characteristic, the strategy of control water level can be used to control the snail in marshland in Poyang Lake region.