A meta-analysis of experimental warming effects on terrestrial nitrogen pools and dynamics

• Published in: The New phytologist Vol. 199; no. 2; pp. 441 - 451
• Main Authors: Bai, Edith, Li, Shanlong, Xu, Wenhua, Li, Wei, Dai, Weiwei, Jiang, Ping
• Format: Journal Article
• Language: English
• Published: England New Phytologist Trust 01.07.2013; Wiley Subscription Services, Inc
• Subjects: Analysis; Carbon sources; Climate change; Cycles; Dynamics; Ecosystem assessment; Environmental changes; Fluxes; Forest ecosystems; Forest soils; Global Warming; Grassland soils; Grasslands; Humidity; Immobilization; increased temperature; Meta-analysis; Microorganisms; Mineralization; N cycling processes; Nitrification; Nitrogen; Nitrogen - metabolism; nitrogen fluxes; Plant Leaves - metabolism; Soil; Soil - chemistry; Soil ecology; Soil heating; Soil microorganisms; Soil moisture; Soil temperature; Soil water; Temperature; Temperature effects; Terrestrial ecosystems; Terrestrial environments
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.12252

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.