Disturbance of plateau zokor-made mound stimulates plant community regeneration in the Qinghai-Tibetan Plateau, China

Mounds constructed by plateau zokors,which is widely distributed in alpine meadows significantly modified plant community structure.However,the variations of plant community structure under the disturbance of plateau zokor-made mound are less concerned.Therefore,we investigated the responses of plant community on zokor-made mound of different years(1 a and 3-4 a),and compared with undisturbed sites(no mound)in an alpine meadow in the eastern Qinghai-Tibetan Plateau(QTP),China.Species richness,coverage and Simpson diversity index were all significantly reduced by the presence of zokor-made mound,but plant heights were significantly increased,particularly in grasses and sedges.Several perennial forage species showed an increased importance value and niche breadth,including Koeleria macrantha,Elymus nutans and Poa pratensis.The effect of zokor-made mound on niche overlap showed that more intense interspecific competition produced a greater utilization of environmental resources.And this interspecific niche overlap was strengthened as succession progressed.The bare mound created by zokor burrowing activities provided a colonizing opportunity for non-dominant forage species,resulting in abundant plant species and plant diversity during the succession period.We concluded that presence of zokor-made mound was conducive to regeneration and vitality of plant community in alpine meadows,thus improving their resilience to anthropogenic stress.