Extreme wet precipitation and mowing stimulate soil respiration in the Eurasian meadow steppe

Tsegaye Gemechu Legesse; Luping Qu; Gang Dong; Xiaobing Dong; Tida Ge; Nano Alemu Daba; Kiya Adare Tadesse; Eba Muluneh Sorecha; Qi Tong; Yuchun Yan; Baorui Chen; Xiaoping Xin; Shao Changliang

doi:10.1016/j.scitotenv.2022.158130

Extreme wet precipitation and mowing stimulate soil respiration in the Eurasian meadow steppe

Sci Total Environ. 2022 Dec 10;851(Pt 1):158130. doi: 10.1016/j.scitotenv.2022.158130. Epub 2022 Aug 20.

Authors

Affiliations

¹ National Hulunbuir Grassland Ecosystem Observation and Research Station & Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
² Forest Ecology Stable Isotope Center, Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
³ School of Life Science, Shanxi University, Taiyuan 030006, China.
⁴ State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo 315211, China.
⁵ State Engineering Laboratory of Efficient Water Use of Crops and Disaster Loss Mitigation/Key Laboratory of Dryland Agriculture, Ministry of Agriculture and Rural Affairs of China, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China.
⁶ National Hulunbuir Grassland Ecosystem Observation and Research Station & Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: shaochangliang@caas.cn.

PMID: 35995168
DOI: 10.1016/j.scitotenv.2022.158130

Abstract

The imbalance of terrestrial carbon (C) inputs versus losses to extreme precipitation can have consequences for ecosystem carbon balances. However, the current understanding of how ecosystem processes will respond to predicted extreme dry and wet years is limited. The current study was conducted for three years field experiment to examine the effects of environmental variables and soil microbes on soil respiration (Rs), autotrophic respiration (Ra) and heterotrophic respiration (Rh) under extreme wet and dry conditions in mowed and unmowed grassland of Inner Mongolia. Across treatments (i.e. control, dry spring, wet spring, dry summer and wet summer), the mean of Rs was increased by 24.9 % and 24.1 % in the wet spring and wet summer precipitation treatments, respectively in mowed grassland. In other hand, the mean of Rs was decreased by -22.1 % and -3.5 % in dry spring and dry summer precipitation treatments, respectively in mowed grassland. The relative contribution of Rh and Ra to Rs showed a significant (p < 0.05) change among simulated precipitation treatments with the highest value (76.18 %) in wet summer and 26.41 % in dry summer, respectively under mowed grassland. Rs was significantly (p < 0.05) affected by the interactive effect of extreme precipitation and mowing treatments in 2020 and 2021. The effects of precipitation change via these biotic and abiotic factors explained by 52 % and 81 % in Ra and Rh, respectively in mowed grassland. The changes in microbial biomass carbon (MBC) and nitrogen (MBN) had significant (p < 0.05) direct effects on Rh in both mowed and unmowed grasslands. The influence of biotic and abiotic factors on Rs was stronger in mowed grasslands with higher standardized regression weights than in unmowed grassland (0.78 vs. 0.69). These findings highlight the importance of incorporating extreme precipitation events and mowing in regulating the responses of C cycling to global change in the semiarid Eurasian meadow steppe.

Keywords: Autotrophic respiration; Clipping; Extreme climatic events; Heterotrophic respiration; Soil microbes.

MeSH terms

Carbon
Ecosystem
Grassland*
Nitrogen / analysis
Respiration
Soil*

Substances

Soil
Carbon
Nitrogen