DOI: 10.1007/s10533-014-9965-2
Scopus记录号: 2-s2.0-84900794675
论文题名: Effects of land use on sources and ages of inorganic and organic carbon in temperate headwater streams
作者: Lu Y.H. ; Bauer J.E. ; Canuel E.A. ; Chambers R.M. ; Yamashita Y. ; Jaffé R. ; Barrett A.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 119, 期: 2018-01-03 起始页码: 275
结束页码: 292
语种: 英语
英文关键词: DIC
; DOM
; Excitation emission matrix-parallel factor analysis
; Land use
; POM
; Stream
; Watershed
Scopus关键词: carbon cycle
; carbon isotope
; dissolved inorganic carbon
; dissolved organic matter
; factor analysis
; headwater
; inorganic carbon
; land use
; organic carbon
; particulate organic matter
; streamwater
; urban development
; watershed
; Chesapeake Bay
; United States
; Virginia
英文摘要: The amounts, sources and relative ages of inorganic and organic carbon pools were assessed in eight headwater streams draining watersheds dominated by either forest, pasture, cropland or urban development in the lower Chesapeake Bay region (Virginia, USA). Streams were sampled at baseflow conditions six different times over 1 year. The sources and ages of the carbon pools were characterized by isotopic (δ13C and {increment}14C) analyses and excitation emission matrix fluorescence with parallel factor analysis (EEM-PARAFAC). The findings from this study showed that human land use may alter aquatic carbon cycling in three primary ways. First, human land use affects the sources and ages of DIC by controlling different rates of weathering and erosion. Relative to dissolved inorganic carbon (DIC) in forested streams which originated primarily from respiration of young, 14C-enriched organic matter (OM; δ13C = -22.2 ± 3 ‰; {increment}14C = 69 ± 14 ‰), DIC in urbanized streams was influenced more by sedimentary carbonate weathering (δ13C = -12.4 ± 1 ‰; {increment}14C = -270 ± 37 ‰) and one of pasture streams showed a greater influence from young soil carbonates (δ13C = -5.7 ± 2.5 ‰; {increment}14C = 69 ‰). Second, human land use alters the proportions of terrestrial versus autochthonous/microbial sources of stream water OM. Fluorescence properties of dissolved OM (DOM) and the C:N of particulate OM (POM) suggested that streams draining human-altered watersheds contained greater relative contributions of DOM and POM from autochthonous/microbial sources than forested streams. Third, human land uses can mobilize geologically aged inorganic carbon and enable its participation in contemporary carbon cycling. Aged DOM ({increment}14C = -248 to -202 ‰, equivalent14C ages of 1,811-2,284 years BP) and POM ({increment}14C = -90 to -88 ‰, 14C ages of 669-887 years BP) were observed exclusively in urbanized streams, presumably a result of autotrophic fixation of aged DIC (-297 to -244 ‰, 14C age = 2,251-2,833 years BP) from sedimentary shell dissolution and perhaps also watershed export of fossil fuel carbon. This study demonstrates that human land use may have significant impacts on the amounts, sources, ages and cycling of carbon in headwater streams and their associated watersheds. © 2014 Springer International Publishing Switzerland.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83703
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 Geological Sciences, University of Alabama, 201 7th Ave, Tuscaloosa, AL, 35485, United States; Aquatic Biogeochemistry Laboratory, Department of Evolution, Ecology and Organismal Biology, Ohio State University, Columbus, OH, 43212, United States; Department of Physical Sciences, Virginia Institute of Marine Sciences, Gloucester Point, VA, 23062, United States; Department of Biology, College of William and Mary, Williamsburg, VA, 23187, United States; Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan; Southeast Environmental Research Center and Department of Chemistry and Biochemistry, Florida International University, Miami, FL, 33199, United States
Recommended Citation:
Lu Y.H.,Bauer J.E.,Canuel E.A.,et al. Effects of land use on sources and ages of inorganic and organic carbon in temperate headwater streams[J]. Biogeochemistry,2014-01-01,119(2018-01-03)