Small Mammal Community Succession After Rechange The Cropland Into Lake In Dongting Lake Region

The Dongting Lake region is located in the middle reaches of the Yangtze Valley and the northern part of Hunan Province, China (28°30'~30°20' N and 111°40'~113°10' E). It situates in a subtropical region, and shows four defined seasons. The weather is warm and humid, with a mean annual temperature of 16~17℃ and a mean annual rainfall varying from 1200 to 1550 mm. It is one of the most important regions for agricultural production in the Yangtze Valley of China.From Tang and Song dynasty, people had begun to reclaim the wetlands such as sandbars and beaches in rivers or/and lakes by using dykes, into polders in order to feed the increasing population. And now polders are the pivotal terrains for agricultural production in Dongting Lake region. Although reclaimation made great contributions to increasing the grain supply and alleviating the intension between the expanding population and land shortage in historic stages, it aggravated the regional flood disasters and limited the wetlands to function as to adjusting and storing floodwater, puring waters and maintaining the biodiversity. In order to restore the wetland ecology system of the lake, defend harm from the flood disaster which was more frequent happened by the end of last century and improve the living level of people in polders, Government of china had decided to rechange the cropland of some polder into lake, which began to be implemented in 1998. How the biology community will be changing in polders after rechanging the cropland into lake is very interesting problem, and also an important science problem. Although there are some studies on the rechangement in Dongting lake region, few studies have analysed associated effects on small mammal communities. So this study was trying to discover the rule of succession of small mammal community after rechanging the cropland into lake in Dongting Lake region.There were two main kinds of ways to rechange the farmland to land: ①DRP (double restoration plolder) , which removed human habitation from polder and gave up associated agricultural activity, and ② SRP (single restoration polder), which only removed human habitat from polder and retained agricultural activity. In DRP, the polder is submerged in the flood...