Characteristics of plant niche under different restoration measures in Ili desert grassland of Xinjiang Uygur Autonomous Region

Abstract

Serious degradation of spring and autumn sagebrush desert steppes was a bottleneck for developing seasonal animal husbandry in northern Xinjiang.In order to restore the sagebrush desert steppes,grazing was seasonally banned or long-term prohib-ited and grassland reseeding was adopted.In this study,the characteristics of niche breadth and niche overlap of 16 Ili desert grassland species were analyzed.The selected grasslands were seasonal grazing banned,long-term grazing prohibited,reseeded and grazed freely.The dominant species(Seriphidium transiliense) had the largest niche breadth,expect in reseeded grassland.S.transil-iense niche breadths in freely grazed grassland,long-term grazing prohibited grassland,seasonally grazing banned grassland were 1.037,1.101 and 1.070,respectively.In also the reseeded grassland,Stipa sp.had the largest niche breadth(0.798).While higher Pianka niche overlap occurred in high niche breadth species,the highest niche overlap occurred in low niche breadth species.Fur-thermore,niche proportion similarity and overlap between S.transiliense and Ceratoides arenarius were high in all four grasslands.This showed an intense interspecies competition for resources between the two species.