Spatial Distribution Patterns and Associations of Woody Plant Species in the Evergreen Broad-Leaved Forests in Central Vietnam

The present study was conducted to elucidate the underlying processes that have maintained and promoted the coexistence of tropical forest tree species. Three 1-ha study plots (100 × 100 m) were established in the evergreen broad-leaved forest in Pu Hoat Nature Reserve, Nghe An Province, Central Vietnam. Uni- and bivariate spatial analyses were performed using the Programita November 2018 software to analyze the spatial patterns and associations of the co-dominant species at a distance of 0–50 m. The results showed that spatial patterns of species were mostly aggregated at a small scale of r < 15 m; randomness and regularity tend to increase at a large scale of r > 15 m. The number of species pairs with independent association accounted for an extremely high proportion (75–90%); attraction and repulsion accounted for a lower proportion (5–12.5%). Spatial association patterns of co-dominant species in the stands were primarily independent or segregated at large scales of r > 30 m. Processes such as limited seed dispersal, habitat heterogeneity, and density-dependent mortality adjusted the spatial distribution patterns and associations of the tree species in the study area.