短期禁牧对天山北坡蒿类荒漠群落特征及其稳定性的影响

摘要

The aim of this study was to explore the response of community characteristics and plant diversity,in deserts in different regions,to grazing exclusion(GE),and to analyze the effects of GE on community stabili-ty.The research was carried out in the Artemisia desert on the northern slopes of the Tianshan Mountains, where the community characteristics were measured and studied.The results showed that 1)GE altered the functional group structure of the desert community in different regions and that community coverage and bio-mass after GE increased significantly by 40.2%~57.0% and 44.4%~81.0%;2)the response of the desert plant diversity indexes to short-term GE were weak,however,the Patrick and Shannon-Wiener indexes of the grazed area in the Manasi desert were significantly higher by 16.7~20.0% than in Qitai and Bole,and the Simpson and Shannon-Wiener indexes of the GE area were significantly higher by 8.6%~1 7.7%;3)short-term GE can maintain the stability of desert communities,and the stability is related to GE times and ecological fac-tors.Therefore,short-term GE can significantly improve desert grassland productivity,and maintain vegeta-tion diversity and community stability.%本研究以天山北坡蒿类荒漠为研究对象,采用野外调查取样的方法,探讨不同区域荒漠围栏内外群落特征和物种多样性对禁牧的响应规律,分析禁牧对生态系统稳定性的影响.结果表明,1)禁牧能改变荒漠植被功能群结构,禁牧后不同生态经济类群群落盖度和生物量分别上升40.2%~57.0%和44.4%~81.0%;2)荒漠群落物种多样性指数对短期禁牧的响应较小,但从区域上看,玛纳斯荒漠放牧区 Patrick丰富度指数、Shannon-Wiener多样性指数比博乐和奇台显著高16.7%~20.0%,而禁牧区 Simpson 优势度指数、Shannon-Wiener 多样性指数、Pielou 均匀度指数高了8.6%~17.7%;3)短期禁牧有利于荒漠群落稳定性的维持,且稳定性可能与禁牧年限和生态环境的变化均有一定的关系.因此,短期禁牧能显著提高荒漠草地生产力,有利于群落物种多样性和群落稳定性的维持.