The Xishuangbanna Rodent Prey Of Castanopsis Class Nuts And Diffusion And Yellow Chest Rat (rattus Tanezumi) Storage Strategy

We chose two kinds of field in Xishuangbanna national natural reserve area, one of which is the evergreen broad-leaved forest in tropical montane, another is the tropical seasonal rain forest. Total 800 plastic-tagged seeds of shortispined evergreen chinkapin(Castanopsis echidnocarpa), cup-shaped evergreen chinkapin(Castanopsis calathiformis), washan evergreen chinkapin (Castanopsis ceratacantha), red evergreen chinkapin(Castanopsis hystrix)were released at this two kind of filed, and we investigated seeds consuming, dispersal and hoarding of the four seed species by rodents. We observed the primary characters of food consuming and hoarding behavior on the tanezumi rat(Rattus tanezumi) in semi-natural enclosure. Major results were listed below:1. In the tropical seasonal rain forest, there were more species and quantities of rodents than the evergreen broad-leaved forest in tropical montana. The forest ecotype is the major rodent ecotype in the two fields, while there were few rodent species belong to the farmland type and the house habitat type. Niviventer confucianus were dominant in all the two kinds of filed.2. We found rodents were the main predator and remover, so it was a very important factor impacting the seeds bank.3. The predation pressure of four seed species from rodents was not very intense, but of spatial heterogeneity. In the tropical seasonal rain forest, the disappearance rate of four seed species was rapid than in the evergreen broad-leaved forest, but in each field, the four seed species had little different in disappearance rate(all p>0.05). We deduced the difference of rodent density was the main factor affecting the disappearance rate in different fields.5. The burial depth was about 1-2cm.The distance of seeds dispersed were less than 10m. In evergreen broad-leaved forest, the distances of the eaten were always farther than the hoarded obviously. There was a contrary situation in tropical seasonal rain forest. The size of seeds and distance of dispersed had no obvious related. Rodents tended to eat and bury the tagged seeds under dense shrub, which was probably due to predation risk in different micro-environments.We investigated food hoarding and eating behavior of tanezumi rat by providing them with peanut,oil tea and pittosporopsis craib seeds within enclosures(L×W×H=10×10×1.5m) in Xishuangbanna, and found that:Tanezumi rat hoarded food in larders; Tanezumi rat consumed and hoarded more peanat and pittosporopsis craib seeds; The sites where food were eaten distributed between the nest and the feeder. This behavior maybe a reflection of escaping from risk,and we found Tanezumi rat ate part of the hoarded food every night.Tanezumi rat consumed 9.28±2.79g equal to 10% of its weight; Tanezumi rat was likely to be a kind of rat harm to farm, while its effect on seeds dispersal and forest renewal was not very obvious.