Litterfall production, decomposition and litter nutrient contents in a mined area revegetated with different forest species

Afforestation of sites disturbed after bauxite mining is the favorite technique to restore all ecosystem functions. The nature of the tree species used for revegetation of post-mining land can accelerate the recovery of soil organic matter and nutrient cycles. This study aimed to determine the litterfall production, decomposition rate and nutrient content from three types of forest cover (Eucalyptus, Anadenanthera peregrina, mixed plantation of 16 native species) planted in a bauxite mining area in recovery. Litterfall production was evaluated monthly over 30 months, and the litter mass was assessed twice a year (dry and rainy periods). Total nutrient content was determined from samples grouped by period (dry and rainy). The annual average values for litterfall dry mass and litter mass were higher in Eucalyptus and mixed native. The period (dry or rainy) did not influence litterfall rates in A. peregrina, but Eucalyptus and mixed native presented higher amounts for litterfall during the rainy and dry periods, respectively. Litter accumulation in Eucalyptus was not affected by the season of the year, but mixed native and A. peregrina presented higher litter accumulation in the dry season. Apparent decomposition rates of A. peregrina and mixed native were higher in the rainy season, highlighting the A. peregrina with the highest values compared with the other forest covers. The mixed native presented the highest leaf content of P, K, Ca and Mg in both the litterfall and litter mass, while Eucalyptus had the lowest P, K, Ca, S and N content and the highest C content in the litterfall. Litterfall production is important in degraded areas to ensure the nutrient return to the soil. The data obtained suggest that the cultivation of a mixed of 16 native trees contribute for produce the higher annual litterfall yields, besides produces leaf litterfall of better nutritional quality in relation to P, K, Ca, Mg and S. Therefore, mixed of native trees can be a promising option for reactivation of nutrient cycling and organic matter formation in mined area of bauxite in the Brazilian Atlantic Forest.

Automated summary

Afforestation is the preferred technique for restoring ecosystem functions in bauxite mining areas. This study found that planting a mixed of 16 native tree species can accelerate the recovery of soil organic matter and nutrient cycles, producing higher litterfall yields and better nutritional quality. Therefore, mixed native trees can be a promising option for reactivation of nutrient cycling and organic matter formation in mined areas of bauxite in the Brazilian Atlantic Forest.