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Aims: To characterise the temporal variability in soil CO2 emissions (FCO2), soil O2 influx (FO2), soil water content (SWC), and soil temperature (Ts) and their relations in long-term reforested areas (30 years of conversion) in an Oxisol, Cerrado biome, Brazil. Methods The following land-use changes (Luces) were evaluated: pine (PI), eucalyptus (EU), and native species (NS) reforested areas. The molar ratio between FCO2 and FO2 (respiratory quotient, RQ) was calculated to better understand the process of soil metabolism. Results: Soil CO2 emission was 28% less in PI than in the other LUCs. A model including Ts, SWC, and FO2 could explain 91 and 62% of the FCO2 temporal variability in NS and PI, respectively. The total FCO2 (November 2015 to May 2016) were 11.26, 10.99, and 7.97 Mg ha-1 for EU, NS, and PI areas, respectively (p < 0.05). The SWC, but not Ts, influenced the temporal variation of FCO2. The first two principal components accounted for 69.32% of the total variability, and two groups distinguished mainly on the basis of soil chemical attributes. Conclusions: Temporal variations of FCO2 in reforested areas in the Cerrado were influenced by edaphoclimatic conditions. Soil carbon stock was influenced by the type of forest and litter on the ground. FO2 was similar in all LUCs studied. The results indicate that RQ of >1 is associated with the effect of root system-mediated soil respiration. Our results suggest that LUCs influence soil carbon input and output—soil carbon dynamics—by changing soil attributes. [ABSTRACT FROM AUTHOR]

The proposal was to investigate the temporal variability of CO 2 emission (FCO2), the influx of O 2 in the soil (FO2), soil moisture (SM) and soil temperature (ST), as well as, understand the process of oxygen entry into the soil. Soil and its relationship with land cover and local climatic conditions. FCO2, FO2, soil moisture and temperature, and other meteorological data (e.g., atmospheric pressure, average air temperature and precipitation). There was a positive linear correlation between the soil's CO 2 emission and O 2 capture and these correlations occurred in areas of mulch and vegetated cover, respectively, r = 0.45 (p < 0.05) and r = 0.44 (p < 0.05). The analysis of variance of temporal variability was significant, which demonstrates that the time and soil cover factors interfere with the dynamics of FCO2 (F = 2.1379; p < 0.0001), FO2 (F = 1.9124; p = 0.003), SM (F = 5.30; p < 0.0001), ST (F = 10.51; p < 0.0001). It is concluded that the temporal variability of the soil's CO 2 emission and O 2 capture is associated with the coverage, soil moisture and atmospheric conditions of the region. Thus, the soil cover provided thermal control and the maintenance of soil moisture. It is hoped that these contributions will serve as an interest in the formation of public policies for the mitigation of greenhouse gases, talking with the objective for sustainable development number 13. • There is a correlation between CO 2 emission and O 2 influx in soil with cover. • Soil moisture influences CO 2 emission rates. • The influx of O 2 is influenced by atmospheric pressure and soil temperature. [ABSTRACT FROM AUTHOR]