Abstract: Spatial point pattern for plant species in the west Qira oasis-desert ecotone under windblown sand was analyzed in this paper. Ripley’s K(t) function was used to analyze the plant community structure, spatial point pattern of plant species and interspecies relationship. The results are as follows: (1) There was no impact of windblown sand on composition of plant species, all the plant communities were consisted of Alhagi sparsifolia Shap., Tamarix ramosissima Ledeb. and Karelinia caspia (Pall.) Less. However, the plant density and coverage were reduced with the increase of wind-blown sand intensity; (2) At a 30m spatial scale, the point distribution of these three plant communities was in an aggregative pattern, and their plant density and coverage were obviously decreased with the increase of wind-blown sand intensity. With the increase of sand burial degree, point pattern of the three plant communities was changed from aggregation to random pattern, and the scale range of aggregate distribution was gradually reduced; (3) Negative correlation among the plant communities was dominant, and it was in a decrease trend with the increase of wind-blown sand intensity. In addition, the causes resulting in the change of spatial distribution of plant communities were the direct disturbance of sand burial, plant adaptability and correlation among the plant communities. The serious sand burial restricted the plant propagation and growth and resulted in the degeneration of the plant communities. Therefore, the oasis-desert marginal zone suffering from severe wind-blown sand is the main conserving area for the oasis safety.

Key words: plant community, point pattern, sand burial, interspecies relationship, Qira oasis, Taklimakan Desert