title: Effects of substrate addition on soil respiratory carbon release under long-term warming and clipping in a tallgrass prairie.
abstract: Regulatory mechanisms of soil respiratory carbon (C) release induced by substrates (i.e., plant derived substrates) are critical for predicting ecosystem responses to climate change, but the mechanisms are not well understood. In this study, we sampled soils from a long-term field manipulative experiment and conducted a laboratory incubation to explore the role of substrate supply in regulating the differences in soil C release among the experimental treatments, including control, warming, clipping, and warming plus clipping. Three types of substrates (glucose, C3 and C4 plant materials) were added with an amount equal to 1% of soil dry weight under the four treatments. We found that the addition of all three substrates significantly stimulated soil respiratory C release in all four warming and clipping treatments. In soils without substrate addition, warming significantly stimulated soil C release but clipping decreased it. However, additions of glucose and C3 plant materials (C3 addition) offset the warming effects, whereas C4 addition still showed the warming-induced stimulation of soil C release. Our results suggest that long-term warming may inhibit microbial capacity for decomposition of C3 litter but may enhance it for decomposition of C4 litter. Such warming-induced adaptation of microbial communities may weaken the positive C-cycle feedback to warming due to increased proportion of C4 species in plant community and decreased litter quality. In contrast, clipping may weaken microbial capacity for warming-induced decomposition of C4 litter but may enhance it for C3 litter. Warming- and clipping-induced shifts in microbial metabolic capacity may be strongly associated with changes in plant species composition and could substantially influence soil C dynamics in response to global change.
authors.affiliation: Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Shapotou Desert Research and Experimental Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, United States of America.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Jia
authors.affiliation: Coastal Ecosystems Research Station of Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, The Institute of Biodiversity Science, Fudan University, Shanghai 200433, China.
authors.forename: Xuhui
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, United States of America.
authors.forename: Yiqi
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, United States of America.
authors.forename: Kai
authors.initials: K
authors.lastname: Xue
authors.affiliation: Shapotou Desert Research and Experimental Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, United States of America.
authors.forename: Xian
authors.initials: X
authors.lastname: Xue
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, United States of America.
authors.forename: Xia
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, United States of America.
authors.forename: Yuanhe
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, United States of America.
authors.forename: Liyou
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, United States of America.
authors.forename: Jizhong
authors.initials: J
authors.lastname: Zhou
mesh_terms: D002244:Carbon / Q000737:chemistry*; D057486:Carbon Cycle; D002245:Carbon Dioxide / Q000737:chemistry; D057231:Climate Change; D065948:Grassland; D012987:Soil / Q000737:chemistry*
chemical_list: D012987:Soil; D002245:Carbon Dioxide; D002244:Carbon