title: Nonlinear responses of soil respiration to precipitation changes in a semiarid temperate steppe.
abstract: Extreme precipitation events are predicted to occur more frequently and will have significant influences on terrestrial ecosystem carbon (C) cycling in the future. However, response patterns of soil respiration to precipitation changes remain uncertain in terrestrial ecosystems. A field experiment with seven precipitation treatments (i.e. from -60% to +60% of ambient precipitation to form a drought to wet precipitation gradient) was conducted over three growing seasons (2010-2012) in a semiarid temperate steppe of Northern China. Results showed a nonlinear response pattern of soil respiration along the experimental precipitation gradient, with soil respiration suppressed by decreased precipitation and enhanced by increased precipitation. Over the three growing seasons, soil respiration was reduced more under the three drought treatments (by 45.8, 32.8, and 15.9% under the -60, -40, and -20% treatments, respectively) than stimulated under the three wet treatments (by 8.9, 14.3, and 18.5% under the +20, +40, and +60% treatments, respectively). Our results indicate that soil respiration was more sensitive to decreased than increased precipitation treatments. The nonlinear and asymmetric responses of soil respiration to precipitation changes should be built into ecosystem models to project ecosystem C cycling associated with climate change.
authors.affiliation: International Joint Research Laboratory for Global Change Ecology, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Miao
authors.affiliation: International Joint Research Laboratory for Global Change Ecology, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Han
authors.affiliation: School of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Du
authors.affiliation: International Joint Research Laboratory for Global Change Ecology, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: International Joint Research Laboratory for Global Change Ecology, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China.|School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Jiang
authors.affiliation: International Joint Research Laboratory for Global Change Ecology, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China.|Department of Biological Sciences, Tennessee State University, Nashville, TN 37209, USA.
authors.forename: Dafeng
authors.initials: D
authors.lastname: Hui
authors.affiliation: International Joint Research Laboratory for Global Change Ecology, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China.
authors.forename: Shiqiang
authors.initials: S
authors.lastname: Wan