关键词: 人为干扰, 群落, 组成, 多样性, 更新

Abstract: Ejina oasis is a powerful eco-line of defense in northwest arid regions of China. However, due to water shortage, water pollution, and the impact of human disturbance, Populus euphratica forests have been severely degraded. We believe that human disturbance will affect the composition of Populus euphratica community and regeneration. The two-way indicator species analysis (TWINSPAN) and canonical correspondence analysis (CCA) were applied to classification and ordination of the Populus euphratica communities by the disturbances of different regions of Ejina. The results show that the understory vegetation's species diversity and root turion's growth were affected by human disturbances. Understory species diversity is mainly affected by tourism disturbance, and the relationship between understory vegetation species diversity and general disturbance intensity follows the intermediate disturbance hypothesis. The relationship between growth status of root turion and grazing disturbance intensity shows a negative correlation. Disturbances can be resisted to some extent if the amount of root turion comes to a certain degree. Moderate human disturbance can increase species diversity. But only by the premise of grazing disturbance being removed can the Populus euphratica forests in Ejina be better renewing.

Key words: human disturbance, community, composition, diversity, regeneration