Drought-induced reduction in methane fluxes and its hydrothermal sensitivity in alpine peatland

Accurate estimation of CH(4) fluxes in alpine peatland of the Qinghai-Tibetan Plateau under extreme drought is vital for understanding the global carbon cycle and predicting future climate change. However, studies on the impacts of extreme drought on peatland CH(4) fluxes are limited. To study the effects of extreme drought on CH(4) fluxes of the Zoige alpine peatland ecosystem, the CH(4) fluxes during both extreme drought treatment (D) and control treatment (CK) were monitored using a static enclosed chamber in a control platform of extreme drought. The results showed that extreme drought significantly decreased CH(4) fluxes in the Zoige alpine peatland by 31.54% (P < 0.05). Extreme drought significantly reduced the soil water content (SWC) (P < 0.05), but had no significant effect on soil temperature (Ts). Under extreme drought and control treatments, there was a significant negative correlation between CH(4) fluxes and environmental factors (Ts and SWC), except Ts, at a depth of 5cm (P < 0.05). Extreme drought reduced the correlation between CH(4) fluxes and environmental factors and significantly weakened the sensitivity of CH(4) fluxes to SWC (P < 0.01). Moreover, it was found that the correlation between subsoil (20 cm) environmental factors and CH(4) fluxes was higher than with the topsoil (5, 10 cm) environmental factors under the control and extreme drought treatments. These results provide a better understanding of the extreme drought effects on CH(4) fluxes of alpine peatland, and their hydrothermal impact factors, which provides a reliable reference for peatland protection and management.