Abstract
Permafrost regions with high soil organic carbon (SOC) storage are extremely vulnerable to global warming. However, our understanding of the temperature sensitivity of SOC decomposition in permafrost regions remains limited, leading to considerable uncertainties in predicting carbon-climate feedback magnitude and direction in these regions. Here, we investigate general patterns and underlying mechanisms of SOC decomposition rate and its temperature sensitivity (Q10) at different soil depths across Tibetan permafrost regions. Soils were collected at two depths (0–10 and 20–30 cm) from 91 sites across Tibetan permafrost regions. SOC decomposition rate and Q10 value were estimated using a continuous-flow incubation system. We found that the SOC decomposition rate in the upper layer (0–10 cm) was significantly greater than that in the lower layer (20–30 cm). The SOC content governed spatial variations in decomposition rates in both soil layers. However, the Q10 value in the upper layer was significantly lower than that in the lower layer. Soil pH and SOC decomposability had the greatest predictive power for spatial variations in Q10 value within the upper and lower layers, respectively. Owing to the greater temperature sensitivity in the lower layer, our results imply that subsurface soil carbon is at high risk of loss, and that soil carbon sequestration potential might decrease in these regions in a warming world.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.