池州市沿江低丘钉螺分布与土地类型和草本植被的关系

Relationship between Oncomelania hupensis fausti Bartsch distribution and land types with herbs in the low hill area along the Changjiang River in Chizhou City

对低丘区6种土地利用类型的钉螺分布特征以及不同土地利用类型钉螺分布与草本特征的关系进行了调查研究。结果表明：（1）滩地杨树林地、旱地、河滩、荒地、沟渠、水田均有钉螺分布，而其他林地类型中并未发现钉螺，有螺框出现率与钉螺密度的大小规律一致，为河滩〉沟渠〉水田〉旱地〉荒地〉滩地杨树林地；（2）最适于钉螺孳生的草本高度、盖度、物种丰富度分别为16—20cm、80％～90％、6～7；（3）滩地杨树林地、旱地、河滩、荒地、沟渠的钉螺密度与草本高度分别呈现Y=0．0248X2＋0．2209x-0．2352、Y=-0．1725x2＋0．9595x-0．8075、Y=．0．0902x2＋0．4055x＋1．7143、Y=0．0667x2＋0．4583x-0．0743、Y=-0．2850x2＋1．5490x-0．9550的关系，旱地、荒地的钉螺密度与草本盖度分别呈现Y=-0．0950x2＋0．3650x＋0．1550、Y=-0．3350x2＋1．9210x-1．7050的关系，滩地杨树林地、旱地、河滩、荒地、沟渠、水田的钉螺密度与草本物种丰富度分别呈现Y=0．0212x2＋0．2057x-0．1781、Y=-0．0581x2＋0．4248x-0．3000、Y=-0．4793x2＋3．0607x-2．4560、y=0．0436x2＋0．2704x＋0．2080、Y=-0．0675x2＋0．7788x．0．9420、Y=-0．128x2＋0．8186x-0．4240的关系。

The characteristics of snail distribution in six land use types, and the relationship between Oncomelania hupensisfausti Bartsch distribution and characteristics of herb in different land use types were investigated in the low hill area. The results were as follows. Firstly, snails were found in bottomland poplar forest land, dry land, beach, wasteland, irrigation canal and paddy field, while there was no snail in other forest land types. Especially, the occurrence rate of snail frame and the density of snail exhibited the same regularity that was beach 〉 irrigation canal 〉 paddy field 〉 dry land 〉 wasteland 〉 bottomland poplar forest land. Secondly, on the whole, the suitable conditions including height, cover degree and species richness of herbs for snails＇ propagation were 16-20 cm, 80%-90%, 6-7, respectively. The relation between density of snail and height of herb showed y=-0.024 8x2 ＋0.220 9x-0.235 2, y=-0.172 5x2＋0.959 5x-0.807 5, y=-0.090 2x2 ＋0.405 5x＋1.714 3, y=-0.066 7x2 ＋ 0.458 3x-0.074 3, y=-0.285 0x2 ＋1.549 0x-0.955 0, respectively in bottomland poplar forest land, dry land, beach, wasteland, irrigation canal, and the relation between density of snail and cover degree of herb were y = - 0.095 0x2 ＋ 0.365 0 x ＋ 0.155 0, y= - 0.335 0 x2 ＋ 1.921 0 x-1.705 0 in dry land, wasteland, respectively. In addition, the rela- tion between density of snail and species richness of herb were y =-0.021 2x2＋ 0.205 7x - 0.178 1, y = -0.058 lx2＋ 0.424 8x - 0.300 0, y=-0.479 3x2 ＋ 3.060 7x-2.456 0, y= - 0.043 6x2＋0.270 4x ＋ 0.208 0, y=-0.067 5x2 ＋ 0.778 8x - 0.942 0, y=-0.128 2X2＋ 0.8186x - 0.4240 in bottomland poplar forest land, dry land, beach, wasteland, irrigation canal and paddy field, respectively.