Spatial Distribution Pattern and Factors Influencing the Endangered Plant Tetracentron sinense Oliv

Tetracentron sinense is a tall deciduous tree and represents the only remaining species of Tetracentron. Currently, the spatial distribution pattern of T. sinense and its associated influencing factors remain unclear, thus hindering its protection and rational utilization. In this study, we employed the point pattern method to analyze the spatial distribution patterns of four representative populations of T. sinense distributed in Baima Snow Mountain, Dafengding, Leigong Mountain, and Foping in China. The results reveal that the T. sinense populations in Baima Snow Mountain, Dafengding, and Leigong Mountain exhibited an aggregated distribution on small (0–10 m) or specific scales, with their spatial distribution patterns shifting from aggregated to random as the scale increased. In contrast, the population of T. sinense in Foping showed a random distribution at all scales. In relation to the factors influencing the spatial distribution patterns of T. sinense, we found that young trees played a crucial role and had a substantial impact on their distribution. Furthermore, adult trees contributed to the aggregated distribution of T. sinense saplings on smaller scales (0–10 m). Additionally, we identified Acer erianthum, Prunus conradinae, and Rhododendron anthosphaerum as key associated species that influenced the formation of spatial distribution patterns of T. sinense. Finally, air humidity and soil moisture content were found to exert a significant effect on the spatial distribution patterns of T. sinense populations. For the protection of T. sinense in situ, it is necessary to increase the number of young trees, enhance the availability of microhabitat factors for its seedlings, and utilize key companion species to promote heterogeneity, which can optimize resource utilization and foster population rejuvenation.