马鹿夏季放牧对祁连山草原群落多样性的影响

Summer grazing of red deer effects on plant diversity of alpine grassland on Qilian Mountain

祁连山草原是我国重要的生态安全屏障,素有“高原冰原水库”和“生命之源”之称,同时也是我国西北地区“江河源”、河西走廊水资源安全的战略基地。祁连山北坡高寒灌丛作为这个安全屏障的重要组成部分,对区域内畜牧业发展的贡献不可忽视。马鹿是祁连山草原重要的特色放牧家畜,目前关于马鹿放牧对高寒灌丛群落学过程的影响研究缺乏。本研究在祁连山中段北麓以甘肃马鹿-高寒灌丛放牧系统为研究对象,探讨了夏季马鹿的放牧强度和地形对高寒灌丛β和γ多样性的影响。结果表明:1)阴坡和谷地放牧强度之间β多样性差异显著,谷地β多样性嵌套现象显著;2)中度放牧促进γ多样性,地形间差异不显著。总体来讲,马鹿适度放牧显著提高了高寒灌丛草地的γ多样性。研究结果以期为祁连山草原的可持续放牧管理提供科学理论依据。

The Qilian Mountains are an important ecological security shield,known as the“plateau reservoir”and“the stream of life”.They are the main water source in the Hexi Corridor,and even in the northwest China.The alpine shrub meadow on the north slope of Qilian mountains has contributed to the development of regional animal agriculture.Red deer(Cervus elaphus kansuensis)is an important and special grazing animal species in the region.At present,there is a lack of research on the influence of grazing by red deer on the community dynamics of alpine shrub rangeland.Therefore,a study both of topographic effects and the effects of red deer grazing on plant community diversity in grazing systems in alpine shrub rangeland at the northern foot of the central Qilian Mountains was conducted.It was found that:1)In the shaded slope and valley aspects,βdiversity was significantly different under different grazing intensities;in the valley topographic category,diversity nesting was evident;2)γdiversity was the highest under moderate grazing intensity and there were no significant differences between different aspects.In general,moderate grazing by red deer significantly improved theβdiversities of alpine shrub meadow.Our study aimed to clarify the influence of red deer grazing on community diversity of alpine shrub rangeland and has provided a scientific and theoretical basis for sustainable grazing management on Qilian Mountain rangeland.