Brazilian Atlantic forest carbon stocks undergoing active restoration after bauxite mining exploration: an approach based on functional attributes

Abstract Background: Tropical forests are important carbon sinks at the global scale. They are important reservoirs of terrestrial carbon and play a fundamental role in global climate regulation. We evaluated the tree species diversity and dominance patterns in stem and carbon stocks in a Brazilian Atlantic forest restored after bauxite mining exploration in the state of Minas Gerais, south-eastern Brazil. Methods: Aboveground carbon was estimated for a permanent 1-ha forest restored after 14 years, measuring all trees with a circumference at breast height (CBH) ≥ 15 cm, planted during restoration. We studied species richness, community composition and stem- and carbon-dominant species based on two categorical functional attributes associated with forest regeneration (successional strategy and dispersal syndrome). Results: The restored forest obtained a high carbon accumulation (~58 Mg ha -1 ), between two and three times more than second-growth forests with the same or more time for natural regeneration, when compared with other restored Brazilian seasonal semideciduous Atlantic Forest stands. The restored forest presented a marked local carbon dominance, with ~7.5% of the tree species of the community representing 50% of the total aboveground carbon (AGC). Anemochoric and zoochoric species presented a similar pattern of carbon dominance, while the initial second-growth species presented a higher carbon storage capacity than the pioneer species. Conclusions: Our findings stress the importance of analysing the relative contributions of species, classified by functional attributes and by their dominance, to ecosystem functioning at fine-scale active restoration.