HOW DO DIFFERENT AMAZON LAND USES AFFECT THE DYNAMICS OF CO 2 EMISSION?

Changes in global climate have an important relationship with CO2 emission into the atmosphere. The implementation of integrated systems in some regions in the Amazon can mitigate CO 2 emissions and improve soil attributes in the medium to long term. In this context, this study aimed to evaluate the CO 2 emission dynamics and its relationship with soil attributes under different uses in the Amazon. The experiment consisted of four treatments characterized by different land uses (Degraded Pasture – DP, Managed Pasture – MP, Native Forest – NF, and Livestock Forest Integration – LF), with 25 replications. Soil CO 2 emission (FCO 2 ), soil temperature (Ts), and soil moisture (Ms) were evaluated over a period of 114 days. Soil samples were collected at the end of this period at a depth of 0 to 0.20 m to determine soil chemical, physical, and biological attributes. The mean FCO 2 reached values of 3.80; 4.44; 3.88; and 3.14 µmol m −2 s −1 in NF, DP, MP, and LF, respectively. In addition to the direct relationship between soil CO 2 emissions and soil temperature for all land uses, soil density indirectly influenced emissions in NF. The amount of humic acid induced the highest emission in DP. The increase in H+Al contents and the reduction in microbial biomass carbon increased emissions in MP. The highest CO 2 emissions came from DP, which had the lowest values of soil moisture and the highest values of soil temperature. Soil organic carbon and carbon stock were higher in MP (8.20 g kg −1 and 21.49 g kg −1 ) and LF (6.01 g kg −1 and 16.12 g kg −1 ), respectively. These values demonstrate that FCO 2 was influenced by the Amazon land uses and highlight LF as a low CO 2 emission system with a higher potential for carbon stock in the soil