中文摘要：

通过放牧实验探讨放牧强度对环湖地区高寒草原地上净初级生产量与再生量的影响。结果表明：①不同放牧强度下牧草的总净初级生产量在2.29只/hm2的放牧强度下出现最大值232.01g/m^2,各放牧小区的净初级生产量均小于对照区,不存在超补偿性生长,极重放牧与对照的差异显著（P〈0.05）;②牧草生长季节地上净初级生产量随放牧强度的增加呈先增后减的趋势,而且极重放牧（4.01只/hm^2）条件下地上净初级生产量最大值的形成日期提前出现;③适宜的放牧强度有利于增加牧草的再生量,在放牧强度为2.29只/hm^2时牧草再生量达到最大。

英文摘要：

The effect of grazing intensity on above-ground net primary productivity and regrowth biomass was studied in alpine-cold grassland around Qinghai Lake by means of grazing experiment.The results showed as follows.①The total net primary productivity under different grazing intensity was the maximum which was 232.01g/m2 when the grazing intensity was 2.29 sheep per hectare.The net primary productivity of every grazing area was less than that of control area and there was not super-compensatory growth.There was a significant difference between heavy grazing and control area（P0.05）.②In grass growing season.the above-ground net primary productivity increased firstly,then decreased with the increasing of grazing intensity,The time of maximun amount of above-ground net primary produtivity was ahead under the condition of very heavy grazing intensity（4.01 sheep per hectare）.③The suitable grazing intensity conduced to increase the regrowth biomass of grass and the regrowth biomass of grass was the maximum when the grazing intensity was 2.29 sheep per hectare.