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

Haidong Wu,Yuan Zhang,Xiaoming Kang,Yong Li,Xiaodong Zhang,Liang Yan,Kerou Zhang,Jinzhi Wang,Zhongqing Yan,Yanbin Hao

doi:10.7717/peerj.8874

Abstract

Accurate estimation of CH4 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 CH4 fluxes are limited. To study the effects of extreme drought on CH4 fluxes of the Zoige alpine peatland ecosystem, the CH4 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 CH4 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 CH4 fluxes and environmental factors (Ts and SWC), except Ts, at a depth of 5cm (P < 0.05). Extreme drought reduced the correlation between CH4 fluxes and environmental factors and significantly weakened the sensitivity of CH4 fluxes to SWC (P < 0.01). Moreover, it was found that the correlation between subsoil (20 cm) environmental factors and CH4 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 CH4 fluxes of alpine peatland, and their hydrothermal impact factors, which provides a reliable reference for peatland protection and management.

Highlights

In recent years, due to the aggravation caused by human activities, the global atmospheric and water cycle pattern has been significantly changed, resulting in an increasing frequency and intensity of global extreme climate events (IPCC, 2013; Kreyling et al, 2008; Kang et al, 2018; Thakur et al, 2017)
The results clearly showed that extreme drought significantly decreased the CH4 fluxes of the peatland ecosystem (Fig. 3B), which was consistent with previous studies (Goodrich et al, 2013; Brown et al, 2013; Malone et al, 2013; Korres et al, 2017)
We found that the condition of extreme drought significantly decreased the CH4 fluxes in the Zoige peatland on the Tibetan Plateau

Summary

Introduction

Due to the aggravation caused by human activities, the global atmospheric and water cycle pattern has been significantly changed, resulting in an increasing frequency and intensity of global extreme climate events (IPCC, 2013; Kreyling et al, 2008; Kang et al, 2018; Thakur et al, 2017). Peatlands play an important role in the global carbon cycle and mitigation of climate change (Wu, 2012)

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Discussion

Conclusion