【摘要】 以三江源区围栏封育5a、10a和自由放牧的高山嵩草草甸为研究对象,对样地内的地上生物量和群落特征的研究结果表明:围栏封育区物种丰富度、物种多样性及生态优势度指数低于自由放牧区,群落结构较自由放牧简单,而均匀度指数高于自由放牧,说明长期围栏封育使群落向均一化方向发展,群落稳定性高于自由放牧草场;可采食的优良牧草生物量及其比例增加,总体趋势是随围栏封育年限增加禾草类生物量围栏内>围栏外,杂类草生物量围栏内<围栏外。更多还原

【Abstract】 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.更多还原