组建地理信息系统数据库是进行种群时空动态分析的前提和基础。

It is the precondition and foundation to build GIS database for analysis of population spatiotemporal dynamics.

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方法 建立查螺环境数据库，以镇为单位组建专业队伍，采用普查与轮查相结合的方法开展查螺。

Methods A database of environment in snail survey was established, and specialized personnel were organized at town level. The general survey combined with survey in turn was used.

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