Localized neighborhood species mingling is correlated with individual tree size inequality in natural forests in South China

Context: Numerous hypotheses such as Janzen–Connell and herd immunity effects have been proposed to explain the coexistence of diverse species in plant communities. However, these mechanisms for maintaining diversity have been studied primarily through the lens of species diversity, whereas tree size diversity or relationships between size and species diversity resulting from local interactions have rarely been investigated.

Aims: We aimed to identify relationships between spatial species mingling and tree size inequality using extensive plot data from species-rich forest ecosystems.

Methods: We applied neighborhood-based methods and explored relationships between spatial species mingling and size inequality indices in 22 large forest plots (30 ha in total) in subtropical and tropical China.

Results: Forest communities with low species mingling, or segregation of heterospecific trees, exhibited increased segregation of trees with dissimilar sizes. In most plots, large trees (e....