Estoque de carbono orgânico no solo sob diferentes usos da terra na Amazônia oriental.

Abstract

The Amazon plays a crucial role in the global carbon cycle, storing a significant amount of carbon in the soil, particularly in the surface layers. However, practices such as deforestation, pasture expansion, and monoculture cultivation have altered these stocks, contributing to climate change. This study was conducted in the eastern Amazon, in the municipality of Bujaru, Pará state, with the objective of evaluating the effects of different land uses (fallow pasture, eucalyptus plantation, and secondary forest) on soil organic carbon stocks. Soil samples were collected from four depths (0–10 cm, 10–20 cm, 20–40 cm, and 40–60 cm) in ten 20 m × 50m plots within each study area. The results showed that carbon stocks were significantly higher in the surface layers (0–10 cm), with fallow pasture storing 0.2997 Mg ha−1 (29.97% of the total), while secondary forest and eucalyptus accounted for 24.81% and 22.17%, respectively. Statistical analysis indicated that carbon stocks varied according to depth, with positive correlations between organic carbon and organic matter (r = 0.67, p < 0.001). Secondary forest showed a more balanced carbon distribution, whereas pasture and eucalyptus concentrated carbon in the upper layers. This study contributes to the understanding of the relationship between land use and carbon sequestration, providing insights for sustainable management practices and climate change mitigation strategies in the Amazon.