Assembly and diversity of plant communities in a páramo ecosystem of the Tropical Andes of Colombia

Abstract Páramos are high-elevation ecosystems in the Tropics, characterized by unique biodiversity with high levels of endemism. The vegetation cover exhibits a typical heterogeneous, patchy pattern, indicating spatial variation associated with local environmental conditions. This study aims to analyze plant community types in relation to species assembly and their associations with environmental variables within a páramo ecosystem in Los Nevados National Park, in the Central Cordillera of Colombia. A total of 58 species-abundance plots were used to identify clustering based on Bray-Curtis dissimilarity, and Non-Metric Multidimensional Scaling was employed to visualize variation in plant communities relative to species. Differences in floristic composition, growth-form abundance, and diversity indices were examined across plant communities. Additionally, community dissimilarities were analyzed in relation to environmental variables. Results are consistent with previous descriptions in the zone and reveal the differentiation of five plant communities in the proper zonal páramo (Cushions, Tussock grasses, Tussock grasses with Stem Rosettes, Mixed, and Shrubs with Tussock grasses), determined by species assembly and the dominance of specific growth forms. Among plant communities, richness, diversity (Simpson) and evenness (Pielou) differ significantly. For terrain and soil variables, only radiation and slope significantly influenced community composition. Previous anthropogenic disturbances in the area (mainly cattle grazing and fire) might have significantly affected the current distribution of vegetation cover, resulting in plant communities at different successional stages. The findings of this study emphasize the importance of quantitative analyses of species assembly for understanding spatial variation in páramo vegetation and for supporting monitoring and conservation efforts.