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调查发现在血吸虫疫区江滩主要防洪林有枫杨林、意杨林、旱柳林和芦苇林。在每一林地内取5块样地(20m×20m),每块样地均设5个样方(1m×1m),统计林底植物种类及覆盖度,测定样地光照和土壤湿度。同时在每个样方内随机设置一平方尺(即0.11m2)的样框调查地表钉螺数并统计其死亡率。经统计分析得出:(1)疫区江滩枫杨林钉螺密度(每0.11m2内个数)与意杨林、旱柳林和芦苇林的差值置信区间分别为8.2809—18.2309、-0.7622—1.6462和5.3190—13.3809;(2)枫杨林下常见的9种植物中,益母草、葎草、紫苏、夹竹桃、篓蒿等与钉螺呈负相关,其中夹竹桃、益母草与钉螺显著负相关,化感作用明显;草、水芹、鸡矢藤和木贼呈正相关;(3)枫杨林群落生态因子与钉螺的相关性表现为:最适宜于钉螺孳生的光照为5×100—15×100lx、土壤湿度为20%—40%、林底植被覆盖度为40%—70%;(4)室内对照实验显示,枫杨鲜叶0.5%浓度水浸液抑螺效果在6d后为84%,优于同浓度凋落物的42.7%钉螺死亡率。上述研究结果可为改善防洪林群落结构,增强防洪林群落抑螺效果提供参考依据。
The survey found that schistosomiasis epidemic area beach main flood control forest Feng Yang Lin, Italian Yang Lin, Salix and reed forest. Five plots (20m × 20m) were taken in each forestland. Five quadrats (1m × 1m) were planted in each plots. The species and coverage of forest plants were measured, and the illumination and soil moisture of plots were measured. At the same time, a sample of one square foot (0.11 m2) was randomly placed in each quadrat to investigate the surface snail number and calculate the mortality rate. The statistical analysis shows that: (1) The confidence interval of the difference between the density of Oncomelania japonicus and Pinus tabulaeformis in the affected area is 8.2809-18.2309, -0.7622 -1.6462 and 5.3190-13.3809, respectively. (2) Nine common species of Pterocarya stenocercae had negative correlation with the snails, including Motherwort, Ephedra, Perilla frutescens, Oleander and Artemisia frigida. Among them, Oleander, (3) The correlation between ecological factors and Oncomelania snails showed that: the most suitable light for snail breeding was 5 × 100-15 × 100lx, the soil moisture was 20% -40%, the vegetation coverage in the forest floor was 40% -70%. (4) The indoor control experiment showed that the inhibitory effect of 0.5% 84%, better than the same concentration of litter 42.7% snail mortality. The results of the above studies can provide reference for improving the community structure of flood control forests and enhancing the effectiveness of snail prevention in the community of flood control forests.