Dynamics of soil organic carbon under uncertain climate change and elevated atmospheric CO₂. (Special Issue: Bioremediation of contaminated soil and water.)

摘要

Climate change and elevated atmospheric CO₂ should affect the dynamics of soil organic carbon (SOC). SOC dynamics under uncertain patterns of climate warming and elevated atmospheric CO₂ as well as with different soil erosion extents at Nelson Farm during 1998-2100 were simulated using stochastic modelling. Results based on numerous simulations showed that SOC decreased with elevated atmospheric temperature but increased with atmospheric CO₂ concentration. Therefore, there was a counteract effect on SOC dynamics between climate warming and elevated CO₂. For different soil erosion extents, warming 1 C and elevated atmospheric CO₂ resulted in SOC increase at least 15%, while warming 5 C and elevated CO₂ resulted in SOC decrease more than 29%. SOC predictions with uncertainty assessment were conducted for different scenarios of soil erosion, climate change, and elevated CO₂. Statistically, SOC decreased linearly with the probability. SOC also decreased with time and the degree of soil erosion. For example, in 2100 with a probability of 50%, SOC was 1617, 1167, and 892 g m-2, respectively, for no, minimum, and maximum soil erosion. Under climate warming 5 C and elevated CO₂, the soil carbon pools became a carbon source to the atmosphere (P>95%). The results suggested that stochastic modelling could be a useful tool to predict future SOC dynamics under uncertain climate change and elevated CO₂.CAS Registry Numbers 7440-44-0 124-38-9