title: A meta-analysis of experimental warming effects on terrestrial nitrogen pools and dynamics.
abstract: Global warming may have profound effects on terrestrial ecosystems. However, a comprehensive evaluation of the effects of warming on ecosystem nitrogen (N) pools and dynamics is not available. Here, we compiled data of 528 observations from 51 papers and carried out a meta-analysis of experimental warming effects on 13 variables related to terrestrial N pools and dynamics. We found that, on average, net N mineralization and net nitrification rate were increased by 52.2 and 32.2%, respectively, under experimental warming treatment. N pools were also increased by warming, although the magnitude of this increase was less than that of N fluxes. Soil microbial N and N immobilization were not changed by warming, probably because microbes are limited by carbon sources. Grassland and shrubland/heathland were less responsive to warming than forest, probably because the reduction of soil moisture by warming offset the temperature effect in these areas. Soil heating cable and all-day treatment appeared to be the most effective method on N cycling among all treatment methods. Results of this meta-analysis are useful for better understanding the response of N cycling to global warming and the underlying mechanism of warming effects on plants and ecosystem functions.
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China.
authors.forename: Edith
authors.initials: E
authors.lastname: Bai
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China.|College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Shanlong
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
mesh_terms: D057232:Global Warming; D006813:Humidity; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D013696:Temperature
chemical_list: D012987:Soil; D009584:Nitrogen
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