title: Costimulation of soil glycosidase activity and soil respiration by nitrogen addition.
abstract: Unprecedented levels of nitrogen (N) have been deposited in ecosystems over the past century, which is expected to have cascading effects on microbially mediated soil respiration (SR). Extracellular enzymes play critical roles on the degradation of soil organic matter, and measurements of their activities are potentially useful indicators of SR. The links between soil extracellular enzymatic activities (EEAs) and SR under N addition, however, have not been established. We therefore conducted a meta-analysis from 62 publications to synthesize the responses of soil EEAs and SR to elevated N. Nitrogen addition significantly increased glycosidase activity (GA) by 13.0%, α-1,4-glucosidase (AG) by 19.6%, β-1,4-glucosidase (BG) by 11.1%, β-1,4-xylosidase (BX) by 21.9% and β-D-cellobiosidase (CBH) by 12.6%. Increases in GA were more evident for long duration, high rate, organic and mixed N addition (combination of organic and inorganic N addition), as well as for studies from farmland. The response ratios (RRs) of GA were positively correlated with the SR-RRs, even when evaluated individually for AG, BG, BX and CBH. This positive correlation between GA-RR and SR-RR was maintained for most types of vegetation and soil as well as for different methods of N addition. Our results provide the first evidence that GA is linked to SR under N addition over a range of ecosystems and highlight the need for further studies on the response of other soil EEAs to various global change factors and their implications for ecosystem functions.
authors.affiliation: Center for Ecological and Environmental Sciences, Northwestern Polytechnical University, Xi'an, 710072, China.|State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.|Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA.
authors.forename: Ji
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA.|Center for Earth System Science, Tsinghua University, Beijing, 100084, China.
authors.forename: Yiqi
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Department of Agriculture and Environmental Sciences, Tennessee State University, Nashville, TN, 37209, USA.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Li
authors.affiliation: Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200062, China.|Center for Global Change and Ecological Forecasting, East China Normal University, Shanghai, 200062, China.
authors.forename: Xuhui
authors.initials: X
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.|Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Junji
authors.initials: J
authors.lastname: Cao
authors.affiliation: Center for Ecological and Environmental Sciences, Northwestern Polytechnical University, Xi'an, 710072, China.
authors.forename: Rui-Wu
authors.initials: RW
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.
authors.forename: Yunqiang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA.
authors.forename: Shelby
authors.initials: S
authors.lastname: Shelton
authors.affiliation: State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Jin
authors.affiliation: Department of Biological Sciences, University of Arkansas, Fayetteville, AR, 72701, USA.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Walker
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
authors.forename: Zhaozhong
authors.initials: Z
authors.lastname: Feng
authors.affiliation: Synthesis Research Center of Chinese Ecosystem Research Network, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Shuli
authors.initials: S
authors.lastname: Niu
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA.
authors.forename: Wenting
authors.initials: W
authors.lastname: Feng
authors.affiliation: Department of Agriculture and Environmental Sciences, Tennessee State University, Nashville, TN, 37209, USA.
authors.forename: Siyang
authors.initials: S
authors.lastname: Jian
authors.affiliation: Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200062, China.
authors.forename: Lingyan
authors.initials: L
authors.lastname: Zhou
mesh_terms: D017753:Ecosystem; D006026:Glycoside Hydrolases / Q000378:metabolism; D009584:Nitrogen; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D012987:Soil; D006026:Glycoside Hydrolases; D009584:Nitrogen
keywords: glycosidase activity; meta-analysis; nitrogen addition; soil respiration; soil type; vegetation type