关键词: 高寒草甸, 草地封育, 地上生物量, 植物学组成, 适宜载畜量

Abstract: From 2012 to 2018, the degraded alpine meadow in Xiaozhongdian Town of Shangri-La City had been chosen and enclosed as test pastures. Aboveground biomass and botanical composition were observed and analyzed for both degraded and enclosed pastures. Redundancy theory, intermediate disturbance hypothesis and threshold value theory were used to evaluate the resistance, resilience, critical threshold and reasonable stocking capacity of the test pastures. The results showed that：（1） pastures enclosure could significantly （P<0.05） increase the aboveground biomass; due to the differences in ecological environment conditions at the test sites and basic situations of the pastures, the inter-annual fluctuation range and variations of the aboveground biomass were inconsistent, but its changing trend with enclosure duration exhibited an power function type （Y=aX^b）; （2） according to the changing trend of aboveground biomass, the resistance of the degraded alpine meadow in the test area was 250.4-518.8 g/m², the pastures resilience was 54.7-68.0 months, and the critical threshold of pastures utilization was 420.6-588.7 g/m²; （3） suitable enclosure period for degraded alpine meadow was 2 to 5 years; continuous enclosure led to redundant growth of forage; the suitable stocking capacity of pastures after 5 years of enclosure was 1.1-3.4 sheep unit/hm²; after 7 years of continuous enclosure, non-feedable plants （including poisonous and harmful plants） in the pastures still accounted for 15.3% to 65.8%, and the suitable stocking capacity was low; （4） enclosure should be combined with measures such as weeds removing to reduce the redundancy of grass community components and to improve the stocking capacity of pastures.

Key words: alpine meadow, pasture enclosure, aboveground biomass, botanical composition, suitable stocking capacity