Neighbourhood effects on tree survival in Huangshan secondary forest community

Understanding inter- and intraspecific interactions is central to community ecology. Using data from two censuses of a subtropical secondary forest in Huangshan, China, we analysed survival rate for over 54,000 saplings across 83 species. We quantified four neighbourhood density indices, conspecific (CI), heterospecific (HI), phylogenetic (PhyI), and functional (FunI), to test how neighbour density influences tree survival. In parallel, we calculated neighbourhood diversity along species, phylogenetic, and functional axes to test how neighbour diversity shapes species' survival probabilities spanning four different spatial scales. Generalized linear mixed models revealed that HI and FI significantly decreased survival, highlighting intense interspecific competition in early successional stages. In contrast, PhyI positively affected survival, suggesting habitat filtering among related species. Neighbourhood diversity exhibited scale-dependent effects. Finally, we identified species with high specific leaf area and phosphorus content grew faster but experienced higher mortality. These findings underscore the importance of incorporating phylogenetic and functional neighbourhood metrics to understand demographic processes and community assembly, particularly in recovering forest ecosystems.