放牧强度对羊草草甸草原植物群落组成及生态位的影响

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关键词：放牧强度；物种多样性；生态位宽度；生态位重叠；草甸草原中图分类号：S812 文献标识码：A 文章编号：1007-0435（2026）02-0403-12

The Influences of Grazing Intensity on the Composition of Plant Communities and Ecological Niches in the Leymus chinensis Meadow Steppe

BI Xin1，YU Tian-qi，SHI Meng-yuan²， XIN Xiao-ping2， ZHANG Zhi-tao1，YAN Rui-rui， HANGuo-dong' （1.CollegeofGrassand Science，InnerMongoliaAgricultural University，Hohhot，InnerMongoliaOlool8，China; 2.InstituteofAgriculturalResourcesandRegionalPlanning，ChineseAcademyofAgriculturalSciences，Beijingo，China）

Abstract：This study aimed to explore the changes and linkages of plant community species diversity and niche under different grazing intensities in （Leymus chinensis） meadow steppe，providing a basis for rational utilization of grassland resources. Taking plant communities in Leymus chinensis meadow steppe under six grazing intensities，including no grazing （ G0=0 cow. AU hm-2 ），light grazing（ G1=0.23 cow. AU hm-2 ），light-moderate grazing（ G2=0.34 cow.AU hm-2 ），moderate grazing（ G3=0.46 cow. AU·hm-2 ），moderate-heavy grazing （ G4=0.69 cow. AU·hm-2 ），and heavy grazing（ G5=0.92 cow. AU ），as research materials，we conducted plant community surveys and calculated diversity indices and niche indices.The results showed that diversity indices first increased and then decreased with increasing grazing intensity，peaking at moderate grazing.The species importance values changed significantly，where the dominant position of Leymus chinensis was replaced by Carex duriuscula as the important values gradualy decreased. The importance value was positively correlated with niche breadth，and the corelation was the strongest under light-moderate grazing and moderate grazing.The niche overlap value first increased and then decreased，while the interspecific competition pressure remained stable under light-moderate grazing and moderate grazing. Therefore，controling the number of graz ing livestock based on the niche breadth and overlap value ofspecies could help stabilize the grassland ecosystem and facilitate the sustainable utilization of grasslands.

Key words：Grazing intensity ;Species diversity ;Niche breadth; Niche overlap;Meadow steppe

呼伦贝尔草原处于欧亚草原的东部边缘地带，总面积为995.08万 hm2 ，占内蒙古草原面积的13.27%[1] 。（剩余22063字）