Distribution Patterns and Intraspecific Spatial Associations of Different Size Classes in Krascheninnikovia ceratoides (L.) Gueldenst. Populations Within the Tibetan Antelope Breeding Grounds of the West Kunlun Mountains

This study analyzed the spatial distribution patterns and intraspecific associations of Krascheninnikovia ceratoides populations across four typical sample plots at different elevations in the Tibetan antelope breeding grounds of the West Kunlun Mountains, categorizing individuals by measured crown surface area rather than validated chronological age. This descriptive analysis compares spatial point patterns among size classes and sites. By integrating GIS, remote sensing, and UAV imagery with field surveys, we applied the g(r) function of point pattern analysis and three null models to investigate population distribution characteristics and intraspecific associations. Across the four sites, some patterns showed clustering at short distances and fell within the simulated model envelopes at many larger distances, but the plots differed in size and distance range; fits to inhomogeneous Poisson and Thomas cluster models did not identify the processes responsible for those patterns. At short distances, some small-class point patterns were clustered; the patterns of intermediate and large size classes varied by plot and distance. Small- and intermediate-sized classes showed positive association at some short distances and null or negative association at some longer distances within individual plots, but spatial association alone does not establish cooperation or competition. Site and elevation are confounded, so these differences do not establish an elevational trend.