DOI: 10.1111/gcb.13112
论文题名: Elevated CO2 promotes long-term nitrogen accumulation only in combination with nitrogen addition
作者: Pastore M.A. ; Megonigal J.P. ; Langley J.A.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2016
卷: 22, 期: 1 起始页码: 391
结束页码: 403
语种: 英语
英文关键词: Brackish marsh
; CO2 enrichment
; Denitrification
; Isotopic biogeochemistry
; Nitrogen pollution
; Nitrogen retention and loss
Scopus关键词: bioaccumulation
; biological uptake
; carbon dioxide
; carbon dioxide enrichment
; denitrification
; ecosystem response
; marsh
; nitrogen
; nitrogen cycle
; carbon dioxide
; nitrogen
; soil
; atmosphere
; chemistry
; ecosystem
; Maryland
; metabolism
; nitrogen cycle
; plant
; soil
; tsunami
; wetland
; Atmosphere
; Carbon Dioxide
; Ecosystem
; Maryland
; Nitrogen
; Nitrogen Cycle
; Nitrogen Isotopes
; Plants
; Soil
; Tidal Waves
; Wetlands
英文摘要: Biogeochemical models that incorporate nitrogen (N) limitation indicate that N availability will control the magnitude of ecosystem carbon uptake in response to rising CO2. Some models, however, suggest that elevated CO2 may promote ecosystem N accumulation, a feedback that in the long term could circumvent N limitation of the CO2 response while mitigating N pollution. We tested this prediction using a nine-year CO2xN experiment in a tidal marsh. Although the effects of CO2 are similar between uplands and wetlands in many respects, this experiment offers a greater likelihood of detecting CO2 effects on N retention on a decadal timescale because tidal marshes have a relatively open N cycle and can accrue soil organic matter rapidly. To determine how elevated CO2 affects N dynamics, we assessed the three primary fates of N in a tidal marsh: (1) retention in plants and soil, (2) denitrification to the atmosphere, and (3) tidal export. We assessed changes in N pools and tracked the fate of a 15N tracer added to each plot in 2006 to quantify the fraction of added N retained in vegetation and soil, and to estimate lateral N movement. Elevated CO2 alone did not increase plant N mass, soil N mass, or 15N label retention. Unexpectedly, CO2 and N interacted such that the combined N+CO2 treatment increased ecosystem N accumulation despite the stimulation in N losses indicated by reduced 15N label retention. These findings suggest that in N-limited ecosystems, elevated CO2 is unlikely to increase long-term N accumulation and circumvent progressive N limitation without additional N inputs, which may relieve plant-microbe competition and allow for increased plant N uptake. © 2016 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61522
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, PA, United States; Smithsonian Environmental Research Center, 647 Contees Wharf Road, Edgewater, MD, United States
Recommended Citation:
Pastore M.A.,Megonigal J.P.,Langley J.A.. Elevated CO2 promotes long-term nitrogen accumulation only in combination with nitrogen addition[J]. Global Change Biology,2016-01-01,22(1)