Interspecific interactions and community stability in an Evergreen Broadleaved Forest: Implications for biodiversity conservation in Bidoup-Nui Ba National Park, Vietnam

Abstract Interspecific interactions and correlations provide vital insights into species relationships and the overall stability of plant communities, which are essential for understanding the dynamics of vegetation restoration and biodiversity conservation. This study examined the interspecific associations and correlations within the evergreen broadleaved forest of Bidoup-Nui Ba National Park in southern Vietnam. The investigation was based on a comprehensive survey of all trees with a diameter at breast height (DBH) greater than 2.5 cm within a 4-ha study plot. A variety of analytical methods, including variance ratio (VR), chi-square test, association coefficient (AC), Ochiai Index, Pearson and Spearman correlation coefficients, and principal component analysis (PCA), were employed to assess the relationships among twelve dominant tree species. The results revealed the following key findings: (1) the community exhibited predominantly positive associations, suggesting a stable successional phase; (2) the ratio of positive to negative correlations exceeded 1, with a significantly higher number of positive correlations, reflecting stronger interspecific associations; (3) Spearman’s rank correlation test demonstrated greater sensitivity compared to other correlation methods; and (4) the classification of ecological species groups aligned with the correlation results, emphasizing the substantial influence of ecological traits and resource utilization strategies on interspecific relationships. These findings highlight the critical role of interspecific interactions in maintaining community stability and provide valuable insights for advancing ecosystem restoration and biodiversity conservation strategies.