Land cover changes affect soil chemical attributes in the Brazilian Amazon

Resumo

Forest plantations may minimize the effects of deforestation in the Amazon. However, there are differences among species in terms of their influences on soil recovery. The effects of monospecific plantations of Acacia mangium, Dipteryx odorata, Jacaranda copaia, Parkia decussata,and Swietenia macrophylla, and areas of pasture and native forest on the chemical soil attributes of the Brazilian Amazon were evaluated. One bulked soil sample was collected per plot (0.00-0.05, 0.05-0.10, and 0.10-0.30 m; three plots of 128 m²) in each area. No significant differences in most of the soil attributes were observed among the forest plantations. However, soil K⁺ and P were higher in the Swietenia macrophylla plantations, while higher values of Ca²⁺, sum of bases, and pH occurred in Jacaranda copaia plantations. In the native forest, the pH, and P content were lower, whereas the soil organic matter (SOM) content, soil organic carbon (SOC) content, cation exchange capacity (CEC), N content, H+Al content, and Al³⁺ content were higher than in the plantations. The lowest values of SOM, SOC, CEC, K⁺, Mg²⁺, N, H+Al, and Al³⁺ occurred in the pasture. None of the forest species led to the return of the original soil chemical attributes of the native forest. However, S. macrophylla and J. copaia plantations presented the highest positive edaphic influences.