Exploring plant functional traits and their relationship to biomass dynamics in secondary forests in Eastern Amazonia

Functional traits and strategies of trees can effectively indicate the progress of forest recovery during succession. This study investigates variations in leaf and wood traits, CSR functional strategies, and trade-offs in resource acquisition adopted by plants in secondary forests of different recovery ages, comparing them to old-growth forests. We also examined the relationships between traits, aboveground biomass dynamics, and edaphic variables in the Bragantina region, Eastern Amazon. Our evaluation focused on leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), and wood density (WD). Secondary forests exhibited higher LDMC and WD compared to old-growth forests, with low trait variation among secondary forests regardless of recovery age. Stress tolerance (S) was the dominant strategy in secondary forests, whereas old-growth forests showed a balanced proportion of stress tolerance and competitive strategies. Coordination was identified among WD, stress strategy (S), and LDMC. Significant relationships were found between functional traits and soil variables. Our results highlight the slow functional recovery of secondary forests in the Bragantina region which is associated with intense land use prior to natural regeneration and the fragmented landscape.