Growth, Biomass and Carbon Stocks in Forest Cover Planted in an Area of Bauxite Mining in Rehabilitation

Abstract

ABSTRACT Forest cover in areas degraded by mining is an alternative way of mitigating CO2 concentrations in the atmosphere by fixing C in tree biomass. This study evaluated the growth and C stocks of forest cover in an area of bauxite mining with four sources of fertilizer. Height (Ht), diameter at ground level (DGL), and diameter at breast height (DBH) were determined in Anadenanthera peregrina (Ap), clonal Eucalyptus (Euc), and a mixed plantation of 16 native forest species (Nat) at 6, 18, 36, and 56 months of age. Trunk+bark volume, biomass, and C stock were also determined for these forest covers at 56 months of age. The fertilization treatments were a standard (SF) adopted by the company, SF plus organic fertilizer (OF), chemical fertilizer (CF), and OF+CF. Euc displayed greater values of Ht, DGL, and DBH under OF+CF and OF. Fertilization did not influence the Ht and DBH of Ap, but DGL was higher under OF+CF at 36 months compared to SF. The Ht values of Nat were influenced by fertilization at 18 months, with the lowest values under SF. The fertilization influenced the DGL of Nat at 36 and 56 months, which did not occur with DBH. The pioneer species had higher Ht, DGL, and DGB compared to non-pioneer species, regardless of the type of fertilization studied. Fertilization influenced the Ht and DGL of pioneer species at 18 and 36 months of age and only the Ht of non-pioneer species. The estimates of Euc biomass (255 Mg ha-1) and C stocks (120 Mg ha-1) under OF+OC were four times greater than in Ap and Nat, which showed no difference between themselves or the types of fertilization. The growth and estimates of volume, biomass, and C stocks of the forest cover were comparable to those of unmined areas. Euc had the greatest growth, biomass, and C stocks.

Keywords

• Brazilian Atlantic Forest
• C sequestration
• land reclamation
• topsoil revegetation
• tree biomass