DOI: 10.1007/s10533-014-0023-x
Scopus记录号: 2-s2.0-84911361384
论文题名: Stable isotopic evidence of enhanced export of microbially derived NO-3 following active layer slope disturbance in the Canadian High Arctic
作者: Louiseize N.L. ; Lafrenière M.J. ; Hastings M.G.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 121, 期: 3 起始页码: 565
结束页码: 580
语种: 英语
英文关键词: Active layer detachments
; Atmospheric deposition
; Denitrification
; High Arctic
; Nitrate
; Nitrification
Scopus关键词: active layer
; atmospheric deposition
; concentration (composition)
; denitrification
; disturbance
; microbial activity
; nitrogen oxides
; oxygen isotope
; permafrost
; stable isotope
; streamwater
; temporal evolution
; watershed
; Canada
; Canadian Arctic
; Melville Island [Queen Elizabeth Islands]
; Queen Elizabeth Islands
英文摘要: Permafrost disturbance is expected to alter nitrogen (N) export in High Arctic watersheds by enhancing loads of dissolved inorganic N (DIN), particularly nitrate (NO-3), by enabling nitrification and/or the mobilization of N previously sequestered in deeper permafrost soils. Using chemical, isotopic, and hydrologic measurements, we compare the seasonal evolution of concentrations and sources of NO-3 in a stream draining an undisturbed catchment with one that drains a catchment that has been affected by active layer detachments (ALDs) at the Cape Bounty Arctic Watershed Observatory (74°54′N, 109°35′W) on Melville Island, Nunavut. Oxygen stable isotope values of NO-3 (δ18O-NO-3) from streamwater indicate that NO-3 in runoff predominantly originated from atmospheric sources in both catchments only during the first days of melt. In the undisturbed catchment, low NO-3 concentrations and elevated streamwater δ18O-NO-3 values relative to the disturbed catchment indicate that NO-3 export was suppressed by sink mechanisms. In contrast, low δ18O-NO-3 values and high NO-3 concentrations in runoff from the disturbed catchment indicate that the supply of NO-3 from microbial sources far outweighed sinks in the watershed. This research demonstrates that ALDs enhanced the export of microbially derived NO-3 relative to undisturbed watersheds, and that this is likely a result of limited NO-3 retention and enhanced nitrification in the mineral soils exposed in the scar zones of ALDs. © 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/83627
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 Geography, Queen’s University, Kingston, ON, Canada; Department of Geological Sciences, Brown University, Providence, RI, United States
Recommended Citation:
Louiseize N.L.,Lafrenière M.J.,Hastings M.G.. Stable isotopic evidence of enhanced export of microbially derived NO-3 following active layer slope disturbance in the Canadian High Arctic[J]. Biogeochemistry,2014-01-01,121(3)