DOI: 10.1007/s10533-014-9986-x
Scopus记录号: 2-s2.0-84904811702
论文题名: Biogeochemical regime shifts in coastal landscapes: The contrasting effects of saltwater incursion and agricultural pollution on greenhouse gas emissions from a freshwater wetland
作者: Helton A.M. ; Bernhardt E.S. ; Fedders A.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 120, 期: 2018-01-03 起始页码: 133
结束页码: 147
语种: 英语
英文关键词: Methane
; Nitrate
; Nitrous oxide
; Restoration
; Seawater intrusion
; Sulfate
英文摘要: Many coastal plain wetlands receive nutrient pollution from agricultural fields and are particularly vulnerable to saltwater incursion. Although wetlands are a major source of the greenhouse gases methane (CH4) and nitrous oxide (N2O), the consequences of salinization for greenhouse gas emissions from wetlands with high agricultural pollution loads is rarely considered. Here, we asked how saltwater exposure alters greenhouse gas emissions from a restored freshwater wetland that receives nutrient loading from upstream farms. During March to November 2012, we measured greenhouse gases along a ~2 km inundated portion of the wetland. Sampling locations spanned a wide chemical gradient from sites receiving seasonal fertilizer nitrogen and sulfate (SO4 2-) loads to sites receiving seasonal increases in marine salts. Concentrations and fluxes of CH4 were low (<100 μg L-1 and <10 mg m-2 h-1) for all sites and sampling dates when SO4 2- was high (>10 mg L-1), regardless of whether the SO4 2- source was agriculture or saltwater. Elevated CH4 (as high as 1,500 μg L-1 and 45 mg m-2 h-1) was only observed on dates when air temperatures were >27 °C and SO4 2- was <10 mg L-1. Despite elevated ammonium (NH4 +) for saltwater exposed sites, concentrations of N2O remained low (<5 μg L-1 and <10 μg m-2 h-1), except when fertilizer derived nitrate (NO3 -) concentrations were high and N2O increased as high as 156 μg L-1. Our results suggest that although both saltwater and agriculture derived SO4 2- may suppress CH4, increases in N2O associated with fertilizer derived NO3 - may offset that reduction in wetlands exposed to both agricultural runoff and saltwater incursion. © 2014 Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83663
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Department of Natural Resources and the Environment, The Center for Environmental Sciences and Engineering, University of Connecticut, Storrs, CT, 06269, United States; Department of Biology, Duke University, Durham, NC, 27708, United States
Recommended Citation:
Helton A.M.,Bernhardt E.S.,Fedders A.. Biogeochemical regime shifts in coastal landscapes: The contrasting effects of saltwater incursion and agricultural pollution on greenhouse gas emissions from a freshwater wetland[J]. Biogeochemistry,2014-01-01,120(2018-01-03)