Grazing significantly affects the distribution, growth, and productivity of shrubs. In this study, we evalu-ated the effects of grazing disturbance on the spatial distri-bution patterns and interspecific relationships of two desert shrubs, Ammopiptanthus mongolicus and Sarcozygium xan-thoxylon. Three types of grazing conditions were considered, including enclosed area (EA), seasonal rotational grazing area (SRGA), and grazing area (GA) (100 m × 100 m), in the West Ordos Nature Reserve of Inner Mongolia, China. The results showed that A. mongolicus and S. xanthoxylon populations were uniformly distributed at a small scale, and the distribution in EA and SRGA became gradually ran-dom. In GA, A. mongolicus population showed aggregated distribution but S. xanthoxylon population showed random distribution at a small scale. Moreover, both A. mongolicus and S. xanthoxylon populations at the 5–7 m scale showed random distribution. At the small and intermediate scales, the two species showed positive interspecific relationships of GA. However, no interspecific relationship was noted between the two species in EA and SRGA. A significant positive relationship (P < 0.01) was noted between the two species at 2–9 m and a negative relationship (P < 0.01) at 13–17 m scales in GA. Positive relationship (P < 0.01) was noted between the two species at 6–13 m scales and a sig-nificant negative relationship (P < 0.01) at 14–24 m scales in SRGA. The two species of desert shrubs showed posi-tive interspecific relationships at the small scale, and they showed negative relationships as the interspecific compe-tition intensified in the presence of grazing disturbance. When the grazing intensity exceeds a certain threshold, the interspecific relationships become weak. Therefore, moder-ate grazing would facilitate interspecific competition and species succession, whereas excessive grazing would disrupt natural competition causing desertification ultimately.

Lei Zhang;Yong Gao;Jinrong Li;Chao Zhang;Minyu Li;Zhao Hu;Xiangxin Cui

College of Desert Science and Engineering,Inner Mongolia Agricultural University,Hohhot 010019, People's Republic of China;Institute of Water Resources for Pastoral Area of the Ministry of Water Resources,Hohhot 010020, People's Republic of China;Institute of Forestry Monitoring and Planning of Inner Mongolia Autonomous Region, Hohhot 010020, People's Republic of China;School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, People's Republic of China

林业研究（英文版）

[1]Lei Zhang;Yong Gao;Jinrong Li;Chao Zhang;Minyu Li;Zhao Hu;Xiangxin Cui-.Effects of grazing disturbance of spatial distribution pattern and interspecies relationship of two desert shrubs)[J].林业研究（英文版）,2022(02):507-518

Sarcozygium,thoxylon,SRGA

Effects,grazing,disturbance,spatial,distribution,interspecies,two,shrubs,Grazing,significantly,affects,growth,productivity,this,study,evalu,effects,patterns,interspecific,relationships,Ammopiptanthus,mongolicus,Three,types,conditions,were,considered,including,enclosed,area,EA,seasonal,rotational,West,Ordos,Nature,Reserve,Inner,Mongolia,China,results,showed,that,xanthoxylon,populations,uniformly,distributed,small,became,gradually,aggregated,random,Moreover,both,At,intermediate,scales,positive,However,was,noted,between,negative,Positive,they,intensified,presence,When,intensity,exceeds,certain,threshold,become,weak,Therefore,moder,would,facilitate,competition,succession,whereas,excessive,disrupt,natural,causing,desertification,ultimately

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