Exploring multiple restoration strategies to recover the Atlantic Forest landscape

Ecological restoration is a promising activity that restores degraded ecosystems and conserves the biodiversity of tropical landscapes. Hoping to achieve better results on a large scale, various strategies and techniques have been used, including passive and active restoration that can impact community structure and landscape characteristics differently. In this study, we evaluated the effectiveness of passive and active restoration in recovering native tree regenerating communities in a degraded area of the Atlantic Forest in southern Brazil. We evaluated the species composition and community structure between passive (natural regeneration) and active (mixed and pure plantations techniques) restoration strategies in young (∼20 years) restoration areas in comparison to the reference ecosystem (old-growth forest). We found similarities between restoration treatments and the reference area, despite the latter being composed of a more diverse community and shade-tolerant species. The three restoration strategies (mixed plantation, Inga edulis plantation, and natural regeneration) converged in terms of the abundance of individuals and tree species composition. Still, they diverged in terms of species richness and diversity, as the areas of natural regeneration were, in general, less species-rich and diverse than the others. Our results show that active restoration of Inga edulis, was more effective in restoring mainly humid soils. These results indicate that diversification of restoration strategies can yield positive outcomes at the landscape scale, and combining multiple forms of restoration is a less costly and more efficient restoration in the context of tropical forest landscapes.