Influence of agricultural productive structure and countermeasures on the rodent population density of the farmland in Dongting Lake area

The influence of agricultural productive structure and countermeasures on the rod ent population density of the farmlands in Dongting Lake area is studied．The results show that the population density of rod ent in paddy field is higher than that in cotton land；and its population density in ha rvested paddy field is higher than that in rape land in the first month of winter，but the population density of rod ent in rape land is higher than that in harvested paddy field in the begin．ning of spring；the population density of rod ent in the non phenol cotton field is higher than that in the phend cottonfield，the po pulation density of rod ent in the field with hardened ridge is lower than that in the field with unhardened ridge．The agricultural productive activities，i．e．the early rice seeding，seeding and harvesting in time，the later rice har．vesting，may cause the migration of rodents owing to the change of the habitats，while the influence on rodent population density is restricted by it propagating characteristics，so the po pulation density of rodent is not affected markedly by themain agricultural productive activities in the farmland．