Enrichment planting to restore degraded tropical forest fragments in Brazil

Abstract

In tropical areas with high levels of fragmentation due to agricultural use, forest fragments play an important role for biodiversity conservation at the landscape scale. But these fragments are subject to recurrent disturbances, which lead to arrested succession and loss of functional groups. In such cases, active restoration, such as enrichment planting, could facilitate recovery. We studied enrichment planting methods to restore tropical forest fragments in the Brazilian Atlantic Forest, and we evaluated the costs to implement them in the field. We planted four later successional tree species as seeds, small seedlings, and large seedlings in three remnants embedded in a landscape dominated by sugarcane plantations. Overall, survival of seedlings was low using all methods due to a severe drought during the study period, and there were no differences in seedling survival or growth across the three study sites. Direct seeding was the least expensive technique but was successful only for one large-seeded species, Hymenaea courbaril. Large seedlings survived better than did small seedlings, for all four species, suggesting that the additional cost of growing large seedlings is warranted to enhance success. Our results highlight that a combination of planting methods at species level is likely to increase restoration success. EDITED BY John Parrotta.