Relationship between Oncomelania hupensis fausti Bartsch distribution and land types with herbs in the low hill area along the Changjiang River in Chizhou City
The characteristics of snail distribution in six land use types, and the relationship between Oncomelania hupensis fausti 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 were16-20 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 relation between density of snail and species richness of herb were y =-0.021 2x2+ 0.205 7x- 0.178 1, y =-0.058 1x2+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.