Soil moisture as a key factor in carbon release from thawing permafrost in boreal forest

In this study, by quantifying the CO2, CH4 releases and the soil properties of moisture, SOC quantity and quality and microbial activities in a 239-day incubation experiment where the soil moisture was experimentally modified to simulate natural, drier and flooded condition, we tested the hypotheses 1) the C vulnerability in permafrost deposits would be higher than that in active layer soils; 2) C releases under aerobic conditions and their climate forcing would be greater than anaerobic condition, but aerobic C release would be constrained by drier condition; and 3) soil moisture would be the strongest factor influencing C release under aerobic condition, whereas anaerobic C release would be mostly related to microbial activities.