Functional recovery of tropical forests: The role of restoration methods and environmental conditions

Abstract

Forest and landscape restoration strategies influence the recovery of plant functional traits, which in turn shape ecosystem processes. To understand how traits respond to restoration and environmental conditions, we assessed the functional recovery of three forest restoration types in Brazil's Atlantic Forest: natural regeneration, high-diversity restoration plantations (20–60 species), and unmanaged tree monocultures. Across 285 plots aged 1–76 years, we quantified seven leaf and stem traits for over 500 species. For each plot, we calculated community mean trait values and three functional diversity indices. The three restoration types showed contrasting successional patterns. Natural regeneration and restoration plantations shifted from acquisitive to conservative resource-use strategies with site age, while monocultures moved in the opposite direction. Restoration plantations exhibited the highest functional richness. Soil conditions (sand content and sum of bases) influenced trait composition and diversity, whereas climate and landscape context had smaller effects. In 20-year old sites, most traits in natural regeneration and restoration plantations approached 90 % of forest remnants values. In contrast, unmanaged monocultures recovered slowly, with only half of the traits reaching this threshold in 40-year old sites. Our findings show that restoration methods and site conditions jointly shape functional recovery. Natural regeneration tends to align with forest remnant traits, restoration plantations speed up early recovery but may diverge over time, and monocultures require active interventions to enhance outcomes. Recognizing these functional trajectories is key to improving biodiversity conservation and ecosystem resilience in tropical forest restoration.