高原鼠兔干扰对藏北高寒草甸微斑块植物多样性的影响

The Effect of Plateau Pika(Ochotona curzoniae)Disturbance on the Plant Diversity of Mini-patches of Northern Tibet Alpine Meadow

高原鼠兔干扰是藏北高寒草甸退化的因素之一,同时也对退化草地中微斑块的植物群落产生影响。为了解以高原鼠兔为主要影响因素的藏北退化高寒草甸微斑块植物群落特征,本文通过野外调查法研究了不同退化程度草地微斑块植物群落的差异。结果表明:严重退化草地微斑块植物群落盖度和生物量显著高于中度退化、轻度退化草地微斑块;各退化程度草地微斑块植物种以菊科、蔷薇科、禾本科、莎草科、玄参科和豆科为主;中度退化草地微斑块植物的物种丰富度和多样性指数显著低于轻度退化、严重退化草地微斑块。说明中度退化草地的高原鼠兔干扰最强烈,微斑块植物多样性受其影响最大;严重退化草地微斑块植物则已开始更新。

In order to understand the characteristics of mini-patch plant communities in degraded alpine meadow in northern Tibet with plateau pika(Ochotona curzoniae)as the key factor,this paper studied the differences of mini-patch plant communities in grassland with different degraded degrees by field investigation.The results showed that the plant community coverage and biomass of mini-patches in severely degraded grassland were significantly higher than those in moderately degraded and mildly degraded grassland.The mini-patch plant species of grassland at different degraded degrees were mainly Compositae,Rosaceae,Gramineae,Cyperaceae,Scrophulariaceae and Leguminosae.The species richness and diversity index of mini-patches in moderately degraded grassland were significantly lower than those in mildly degraded and severely degraded grassland.It indicated that the plateau pika with moderate degraded grassland had the strongest disturbance,and the mini-patch plant diversity was affected the mostm.Furthermore,the severely degraded grassland mini-patch plants had begun to renew.