Differential responses of plant and microbial respiration to extreme precipitation and drought during spring and summer in the Eurasian meadow steppe

• Published in: Environmental research Vol. 269; p. 120883
• Main Authors: Legesse, Tsegaye Gemechu, Xiao, Jingfeng, Dong, Gang, Dong, Xiaobing, Daba, Nano Alemu, Abeshu, Guta Wakbulcho, Qu, Luping, Zhu, Wen, Wang, Lulu, Xin, Xiaoping, Shao, Changliang
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 15.03.2025
• Subjects: carbon; Carbon Cycle; cell respiration; climate; Climate Change; drought; Droughts; ecosystem respiration; Extreme drought; Extreme precipitation events; Grassland; Heterotrophic respiration; meadows; photosynthesis; Plant biomass; Plants - metabolism; Rain; Rainout shelters; Random forest; Seasons; spring; steppes; summer; variance; Heterotrophic respiration; Random forest; Extreme precipitation events; Plant biomass; Rainout shelters; Extreme drought
• ISSN: 0013-9351; 1096-0953; 1096-0953
• DOI: 10.1016/j.envres.2025.120883

Increasing extreme precipitation and drought events along changes in their seasonal patterns due to climate change are expected to have profound consequences for carbon cycling. However, how these climate extremes impact ecosystem respiration (Reco) and whether these impacts differ between seasons remain unclear. Here, we reveal the responses of Reco and its components to extreme precipitation and drought in spring and summer by conducting a five-year manipulative experiment in a temperate meadow steppe. Based on a 5-year average, the seasonal mean values (±SE) of Reco, Rh, Rroot, Rabg and Rplant significantly increased (p < 0.01) under both extreme precipitation treatments: wet spring (WSP) and wet summer (WSU), and significantly decreased (p < 0.01) under both extreme drought treatments: dry spring (DSP) and dry summer (DSU), except in Rabg under DSU, which remained comparable to the control. The sensitivity of Reco, Rh, Rroot and Rplant to extreme precipitation was significantly higher in spring than in summer. On average, Rplant was the primary contributor of Reco, accounting for 37.18% and 38.31% of the total across all its components under WSP and WSU, respectively during the growing season over the five study years. Moreover, linear models revealed Rplant explained 87% of the variance in Reco. Our findings indicate that future changes in precipitation events, particularly extreme precipitation may lead to increased carbon release from ecosystems, largely driven by enhanced plant respiration rather than microbial respiration. However, due to this study focused solely on respiration and did not measure photosynthesis, the findings represent only the carbon release processes and do not account for potential carbon uptake by plants during the same conditions. These emergent identified contribution to ecosystem respiration provide valuable insights for improving model benchmarks to better predict ecosystem respiration responses to extreme climate in specified season. •Rplant contributed more to Reco than Rh during extreme precipitation.•Ecosystem respiration sensitivity to extreme precipitation was higher in spring than summer.•Extreme drought significantly reduced Reco and its components.•MBC showed a minimal response to extreme precipitation treatments.