Analysis of Plant Community Characteristics of Kobresia pygmaea Meadow in the Three Headwaters under Fencing and Grazing

The three headwaters fenced for 5a,10a and free grazed in Kobresi apygmaea meadow were as the research object,the above ground biomass and community characteristics were studied.The results showed that:the species richness,diversity and dominance under fencing were lower than that under free grazing,the structure of community under fencing was simpler than that under free grazing,however evenness under fencing was higher that that under grazing,which showed that long-term fencing made the community homogenization,community stability was higher than that under free grazing,the fine herbage biomass and proportion were increased,and with the increase of enclosure years,the overall trend was that the grass biomass in fencing area was greater than that in grazing area,the forbs biomass smaller than that in grazing area.