摘要
通过对不同牧压梯度导致的4个相邻高寒草甸植物群落物种多样性的调查,探讨了放牧驱动下高寒草甸演替及植物物种多样性分异特征,以期为高寒草甸合理利用提供依据。结果表明:矮嵩草时期与小嵩草草毡表层开裂期的多样性指数D差异不显著,其他3个阶段间差异显著(P<0.05);多样性指数H除禾草矮嵩草时期与小嵩草草毡表层开裂期,矮嵩草时期与小嵩草草毡表层加厚期差异不显著外,其他均差异显著(P<0.05);均匀度指数除矮嵩草时期与小嵩草草毡表层加厚期差异不显著,其他3个时期差异均达到显著水平(P<0.05);放牧明显改变了高寒草甸的主要建群种和优势种,伴随牧压强度增大,植物群落发生更替,莎草科重要值增大,禾本科重要值减小,草甸植物群落由禾草矮嵩草时期向矮嵩草时期、小嵩草草毡表层加厚期、小嵩草草毡表层开裂期演替。
A comparative study on four adjacent plant community species characteristics with different grazing intensities was conducted in alpine meadows.The variations of plant species diversity at different suecessional stages were discussed under different grazing gradients,aiming to provide the basis of vegetation protection in this region.The results showed that Shannon-Wiener index changed indistinctively between the stage of Kobresia humilis community and matticepipedon cracking stage of K.pygmaea community,however,it changed significantly among the other three stages.Simpson index did not significantly change between the matticepipedon cracking stage of K.pygmaea community with Gramineae and K.humilis community stage,matticepipedon thickening stage of K.pygmaea community and K.pygmaea community,whereas significantly changed among other stages.The evenness indices based on the Shannon — Wiener index did not change significantly between K.pygmaea community and matticepipedon thickening stage of K.pygmaea community,whereas it changed significantly among the other three stages.Grazing measure significantly changed the constructive species and dominant species of meadow,resulting in the change of species important value.With the increases of grazing pressure,the plant community was significantly changed.The community succession of the alpine meadow was from Gramineae and K.humilis community to K.pygmaea community,matticepipedon thickening stage of K.pygmaea community to matticepipedon cracking stage of K.pygmaea community.The important value of Cyperaceae species increased with the successions of communities in the alpine meadow,whereas the important value of Gramineae species decreased.
出处
《草地学报》
CAS
CSCD
北大核心
2015年第5期944-950,共7页
Acta Agrestia Sinica
基金
国家自然科学基金面上项目(31270576)
青海省科技厅项目(2013-N-540)(2013-Z-915)资助
关键词
牧压梯度
高寒草甸
演替
物种多样性
Grazing pressure gradient
Alpine meadow
Succession
Species diversity
