Spatial point pattern of shrubland on fixed sand dunes in the Mu Us Sandy Land, China.

We investigated the mechanisms underlying the spatial point patterns of sand-fixing shrubs, including and the coexisting shrubs var. , , and in the Mu Us Sandy Land. The pair correlation functions () and null models were used to analyze the spatial distribution patterns and correlations of at different growth stages, as well as the spatial dynamics of the three coexisting shrubs. The results showed that under the influence of seed dispersal limitation, and the three coexisting shrubs, predominantly exhibited a spatial pattern of small-scale aggregated and large-scale random distribution. Intraspecific associations of were largely positive or non-significant, primarily influenced by seed dispersal limitations. After excluding habitat heterogeneity, interspecific associations between and , as well as between and , displayed positive correlations at small scales (0-4 and 0-2 m) but no significant correlations at medium and large scales (3-20 and 2-11, 13-20 m). There was no significant correlation between and at small and medium scales (0-13 m), but negative correlation at large scales (13-20 m). The spatial associations between young and the three coexisting shrubs were weakest across different growth stages. In contrast, vegetative and reproductive individuals showed similar trends, with both displaying positive associations at small scales.