Asynchronous responses of microbial CAZymes genes and the net CO2 exchange in alpine peatland following 5 years of continuous extreme drought events

Zhongqing Yan; Enze Kang; Kerou Zhang; Yanbin Hao; Xiaodong Wang; Yong Li; Meng Li; Haidong Wu; Xiaodong Zhang; Liang Yan; Wantong Zhang; Jie Li; Ao Yang; Yuechuan Niu; Xiaoming Kang

doi:10.1038/s43705-022-00200-w

Asynchronous responses of microbial CAZymes genes and the net CO₂ exchange in alpine peatland following 5 years of continuous extreme drought events

ISME Commun. 2022 Nov 16;2(1):115. doi: 10.1038/s43705-022-00200-w.

Authors

Zhongqing Yan^{1

2

3}, Enze Kang^{1

2

3}, Kerou Zhang^{1

2

3}, Yanbin Hao⁴, Xiaodong Wang^{1

2

3}, Yong Li^{1

2

3}, Meng Li^{1

2

3}, Haidong Wu⁵, Xiaodong Zhang^{1

2

3}, Liang Yan^{1

2

3}, Wantong Zhang⁶, Jie Li⁷, Ao Yang^{1

2

3}, Yuechuan Niu⁴, Xiaoming Kang^{8

9

10}

Affiliations

¹ Wetland Research Center, Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, 100091, Beijing, China.
² Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, Ngawa, 624500, China.
³ Beijing Key Laboratory of Wetland Services and Restoration, 100091, Beijing, China.
⁴ College of Life Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China.
⁵ Information Center of Ministry of Ecology and Environment, 100029, Beijing, China.
⁶ Sino-Danish Centre for Education and Research, University of Chinese Academy of Sciences, 100049, Beijing, China.
⁷ State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China.
⁸ Wetland Research Center, Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, 100091, Beijing, China. xmkang@ucas.ac.cn.
⁹ Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, Ngawa, 624500, China. xmkang@ucas.ac.cn.
¹⁰ Beijing Key Laboratory of Wetland Services and Restoration, 100091, Beijing, China. xmkang@ucas.ac.cn.

Abstract

Peatlands act as an important sink of carbon dioxide (CO₂). Yet, they are highly sensitive to climate change, especially to extreme drought. The changes in the net ecosystem CO₂ exchange (NEE) under extreme drought events, and the driving function of microbial enzymatic genes involved in soil organic matter (SOM) decomposition, are still unclear. Herein we investigated the effects of extreme drought events in different periods of plant growth season at Zoige peatland on NEE and microbial enzymatic genes of SOM decomposition after 5 years. The results showed that the NEE of peatland decreased significantly by 48% and 26% on average (n = 12, P < 0.05) under the early and midterm extreme drought, respectively. The microbial enzymatic genes abundance of SOM decomposition showed the same decreasing trend under early and midterm extreme drought, but an increasing trend under late extreme drought. The microbial community that contributes to these degradation genes mainly derives from Proteobacteria and Actinobacteria. NEE was mainly affected by soil hydrothermal factors and gross primary productivity but weakly correlated with SOM enzymatic decomposition genes. Soil microbial respiration showed a positive correlation with microbial enzymatic genes involved in the decomposition of labile carbon (n = 18, P < 0.05). This study provided new insights into the responses of the microbial decomposition potential of SOM and ecosystem CO₂ sink function to extreme drought events in the alpine peatland.

Abstract

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