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

Abstract

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.