Effects of different grazing intensity on population density,body weight,blood glucose and blood lipid of Spermophilus dauricus
Overgrazing has led to grassland degradation,creating a suitable living environment for some rodents,and ex-acerbating grassland degradation and rodent infestation.Daurian ground squirrel(Spermophilus dauricus)is a ground-dwelling Sciuridae and is a typical seasonal hibernator mainly distributed in the grassland and the agricultural-pastoral zone in northern China.To analyze the effects of grazing and vegetation cover on the population density,body weight,blood glucose and blood balance of Daruian ground squirrels,we selected field plots with different distances between vil-lages(near village and far from village)at Heishitou town,Erguna,Hulunbuir Grassland.The field plots near village showed high grazing intensity,while the field plots far from village showed low grazing intensity.Our results showed that the burrow density and capture rate of the ground squirrels in high grazing intensity plots were significantly higher than those in low grazing intensity plots.The body weight and blood triglyceride concentration of the ground squirrels in the high grazing intensity plots were significantly higher than those in the low grazing intensity plot,while the serum glucose of ground squirrels in the low grazing intensity plots was significantly higher than that in the high grazing inten-sity plots.The total dry matter of vegetation in high grazing intensity plots was significantly higher than that in low graz-ing intensity plots,and the total dry matter and quantity of Leymus chinensis in high grazing intensity plots were signifi-cantly higher than those in low grazing intensity plots,and there were also differences on vegetation types.The above results indicate that grazing may change the type and quantity of vegetation in the grassland ecosystem through livestock trampling,feeding,and excrement,which provides more abundant and high-quality food resources for Daurian ground squirrels,promotes the accumulation of fat,and is conducive to the survival and reproduction of this species.These re-sults are helpful in understanding the environmental adaptation of Daurian ground squirrels and provide a theoretical ba-sis for the establishment of an environmentally friendly integrated management system for rodent pests,which has signif-icance for the protection of biodiversity and the maintenance of ecological balance.