Abstract: Spatial distribution and interspecific association of plant species are important for revealing how species interact with each other and response to environment change, and hence have important implications for optimal community management and regeneration of degenerated ecosystems. Community structure and interspecies association in the ecotone between mobile sand dunes and interdune lowland in the Horqin Sandy Land were studied using the Pearson correlation, Spearman rank correlation and multivariate analysis (Correspondence Analysis, CA). The results indicated that the difference of species distribution was jointly affected by both environment and biotic factors. There was a selective interspecies accumulation. However, the niches of Agriophyllum squarrosum and Artemisia wudanica were separated from those of other species because they were distributed independently. Salix gordejevii and S. microstachya occupied a similar niche since both of them were distributed on the left side of interdune lowland, but the niche of Hedysarum fruticosum was separated from the niches of other two because it mainly distributed on the other side of interdune lowland. The results of Pearson correlation test were basically consistent with those of Spearman rank correlation test. The community was in unstable succession because the negative correlation coefficients were higher than the positive ones, and there was a niche differentiation.

Key words: font-family: 宋体, mso-bidi-font-family: 宋体, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mobile dune')">mso-bidi-language: AR-SA">mobile dune, interdune lowland, ecotone, spatial distribution, interspecific association, correlation test, Horqin Sandy Land