Phylogenetic clustering of tree communities decreases with stand age and environmental quality along a mineland rehabilitation chronosequence

Abstract

Continuous systematic monitoring is necessary to measure the success or failure of mineland rehabilitation. Here, we aimed to outline how measures of phylogenetic diversity and phylogenetic community structure complement existing monitoring frameworks along a waste pile rehabilitation chronosequence in Carajás National Forest, Brazil, including primary rainforest as the desired outcome. We pruned the megatree R20160415.new to tree species found in this study and computed the phylogenetic diversity (PD), mean pairwise distance (MPD) among taxa and individuals and their standard effect sizes (ses.PD and ses.MPD) via the 'phylogeny pool' null model. PD and MPD increased with rehabilitation progress. Dominance of Fabales species caused phylogenetic clustering during early rehabilitation stages. This clustering disappeared in older stands and switched to phylogenetic overdispersion at reference sites, indicating that mechanisms impeding the recruitment of species from certain phylogenetic lineages during initial stages, such as environmental filtering, tend to decrease with rehabilitation advancement. Furthermore, this pattern indicates the recovery of coexistence-stabilizing interactions with rehabilitation time, even if a constrained number of species was used to launch rehabilitation. Positive associations between all phylogenetic variables and previously determined measures of environmental quality indicate the importance of community assembly processes and niche diversification for ecosystem performance in rehabilitating minelands.

Keywords

• Phylogenetic structure
• Environmental monitoring
• Carajás National Forest
• Community assembly
• Coexistence-stabilizing interactions