中文摘要：

针对草地畜牧业中天然草地的科学管理和合理利用问题，选取围栏禁牧、生长季休牧冬季放牧和全年连续放牧3个处理样地，研究了不同放牧方式对环青海湖区高寒草原群落特征的影响。结果表明：围栏禁牧休牧后，地上生物量和植被盖度显著增加；禾本科和莎草科植物的优势度增加，杂类草优势度减小；优良牧草比例增加，杂类草比例下降。休牧区物种丰富度指数和多样性指数最高，禁牧区多样性指数最低。综合考虑植物多样性、草地生产力和群落物种组成与结构，休牧是较为理想的草地管理和利用方式。草地在围栏封育一段时间后，应该进行适当的利用（放牧或割草），进而保持草地生态系统的平衡稳定。

英文摘要：

Based on the scientific management and rational utilization of grassland animal husbandry, ban- ning grazing, continuous grazing and delaying grazing during growing season were selected as research ob- jects. The effects of banning and delaying grazing on the community characteristics of alpine steppe in Qinghai Lake Region were investigated. Results showed that after banning and delaying grazing, aboveground biomass and vegetation coverage increased significantly. The dominance of grass and sedges increased, whereas the dominance of forbs decreased. And the yield ratio of forage grasses increased, while the yield ratio of forbs decreased. The delaying grazing land had the highest species richness and di- versity indices, whereas the banning grazing land had the lowest diversity index. Comprehensive research of community composition and structure, yield, and species diversity indicated that delaying grazing was a more reasonable compromise of grassland management and utilization. The grassland should be utilized properly （grazing or mowing the lawn） after fenced enclosure to maintain the balance and stability of grassland ecosystem.