四川紫色浅丘区钉螺分布空间分布格局与抑螺林布局的关系

本文在解析山丘区钉螺分布特征的基础上、提出了浅丘区的抑螺林分类及体系布局。结果表明：（1）该流域钉螺平均密度为4．05只·0．11m^-1，活螺框出现率为34．00％；（2）钉螺密度和活螺出现率均以林地最低，旱地其次，而水田、河滩、荒坡和沟渠较高；（3）不同环境类型活螺出现率依次为：洲滩〉湖滩〉沟〉河〉林地〉塘。该区域的抑螺防病林可分为河渠抑螺林、坡地抑螺林、农田抑螺林和多功能抑螺林四种类型、各种林分类型在树种选择、组成、功能上各有不同，但抑螺林的布局必须以降低钉螺密度、减少人畜感染机率为主要目标，同时兼顾经济及生态方面的效益。

The Relationship between Patterns of Spatial Distribution of Oncomelania and Layout of Oncomelania-controlling Forest in Purple Shallow Hilly Areas of Sichuan

Based on oncomelania distribution characteristics in purple shallow hilly areas of Sichuan, types and layout of oncomelania-controlling forest is put forward in the paper. The results have shown that： （ 1 ） The mean density is 4. 05 snails - 0. 11 m-2 ,and the living snail frame occurrence rate is 34% in the watershed ; （2） The regularity of oncomelania density is that paddy fields 〉 irrigation canal 〉 wastelands 〉 beaches 〉 arable lands 〉 forestlands （ 3 ） Another regularity of occurrence rate of living snail frame is that paddy fields 〉 beaches 〉 wastelands 〉 irrigation canal 〉 arable lands 〉 woodlands. According to the law of distribution of the oncomelania in the hilly and mountains district, oncomelania-controlling forest is divided into four types, namely, river-ditch mode, slope mode, field mode and multifunction mode. Each mode is varied in aspects of tree species, composition and function. Reducing oncomelania density and infection rate of snail fever is a chief object of planting oncomelania-controlling forest, and at the same time, attention must be paid to benefits of ecology and economy.