title: A cross-biome synthesis of soil respiration and its determinants under simulated precipitation changes.
abstract: Soil respiration (Rs) is the second-largest terrestrial carbon (C) flux. Although Rs has been extensively studied across a broad range of biomes, there is surprisingly little consensus on how the spatiotemporal patterns of Rs will be altered in a warming climate with changing precipitation regimes. Here, we present a global synthesis Rs data from studies that have manipulated precipitation in the field by collating studies from 113 increased precipitation treatments, 91 decreased precipitation treatments, and 14 prolonged drought treatments. Our meta-analysis indicated that when the increased precipitation treatments were normalized to 28% above the ambient level, the soil moisture, Rs, and the temperature sensitivity (Q10) values increased by an average of 17%, 16%, and 6%, respectively, and the soil temperature decreased by -1.3%. The greatest increases in Rs and Q10 were observed in arid areas, and the stimulation rates decreased with increases in climate humidity. When the decreased precipitation treatments were normalized to 28% below the ambient level, the soil moisture and Rs values decreased by an average of -14% and -17%, respectively, and the soil temperature and Q10 values were not altered. The reductions in soil moisture tended to be greater in more humid areas. Prolonged drought without alterations in the amount of precipitation reduced the soil moisture and Rs by -12% and -6%, respectively, but did not alter Q10. Overall, our synthesis suggests that soil moisture and Rs tend to be more sensitive to increased precipitation in more arid areas and more responsive to decreased precipitation in more humid areas. The responses of Rs and Q10 were predominantly driven by precipitation-induced changes in the soil moisture, whereas changes in the soil temperature had limited impacts. Finally, our synthesis of prolonged drought experiments also emphasizes the importance of the timing and frequency of precipitation events on ecosystem C cycles. Given these findings, we urge future studies to focus on manipulating the frequency, intensity, and seasonality of precipitation with an aim to improving our ability to predict and model feedback between Rs and climate change.
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093, China.
authors.forename: Lingli
authors.initials: L
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093, China.|University of Chinese Academy of Sciences, Yuquanlu, Beijing, 100049, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Integrative Biology, University of South Florida, Tampa, FL, 33620, USA.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Lajeunesse
authors.affiliation: Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27659, USA.
authors.forename: Guofang
authors.initials: G
authors.lastname: Miao
authors.affiliation: Department of Ecology, College of Urban and Environmental Science, Peking University, Beijing, 100871, China.
authors.forename: Shilong
authors.initials: S
authors.lastname: Piao
authors.affiliation: State Key Laboratory of Cotton Biology, Key Laboratory of Plant Stress Biology, College of Life Sciences, Henan University, Kaifeng, 475004, Henan, China.
authors.forename: Shiqiang
authors.initials: S
authors.lastname: Wan
authors.affiliation: Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093, China.|University of Chinese Academy of Sciences, Yuquanlu, Beijing, 100049, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093, China.|University of Chinese Academy of Sciences, Yuquanlu, Beijing, 100049, China.
authors.forename: Sen
authors.initials: S
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093, China.|University of Chinese Academy of Sciences, Yuquanlu, Beijing, 100049, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093, China.|University of Chinese Academy of Sciences, Yuquanlu, Beijing, 100049, China.
authors.forename: Meifeng
authors.initials: M
authors.lastname: Deng
mesh_terms: D057231:Climate Change; D055864:Droughts; D011891:Rain; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013696:Temperature; D014867:Water / Q000032:analysis
chemical_list: D012987:Soil; D014867:Water
keywords: apparent Q10; aridity index; drought; meta-analysis; precipitation regime; soil moisture; soil temperature; wet