DOI: 10.1007/s10533-014-0006-y
Scopus记录号: 2-s2.0-84918773020
论文题名: Controls on soil nitrification and stream nitrate export at two forested catchments
作者: Casson N.J. ; Eimers M.C. ; Watmough S.A.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 121, 期: 2 起始页码: 355
结束页码: 368
语种: 英语
英文关键词: Forest
; Nitrate
; Nitrification
; Stream export
; Winter
英文摘要: Dormant season inorganic nitrogen (N) leaching varies considerably among forested catchments with similar bedrock, forest cover and deposition history. Recent work has highlighted the importance of winter rain-on-snow (ROS) events as a source of winter nitrate (NO3-N) export, but differences among streams are likely due to differences in baseflow NO3-N concentrations, and thus soil N processes. The objective of this study was to investigate rates of N-mineralization and nitrification as well as their potential environmental controls throughout the year, but with particular focus on the winter season in south-central Ontario, Canada. Field incubations were utilized to assess differences in NO3-N and ammonium production over time and across topographic positions in two catchments with contrasting patterns of N export. Rates of nitrification were similar to rates of total mineralization, and nitrification rates were significantly higher during the summer and spring compared with the winter and fall; however, winter nitrification was substantial, and ranged from 19 to 36 % of annual rates. Seasonal differences in nitrification were largely driven by temperature, soil moisture and inorganic N concentration in soil. Rain and melting snow infiltrated the soil during ROS events, which were associated with increased NO3-N availability, particularly in well-drained soils, and ROS-induced increases in stream nitrate concentrations were largest at the catchment dominated by well-drained soil. Annual nitrification fluxes were almost two orders of magnitude greater than N deposition or NO3-N leaching fluxes at either catchment. Similar rates of NO3-N production within the two catchments suggest that consumption of NO3-N within wet soils is responsible for the 10-fold difference in NO3-N export between the two streams. Notably, these results suggest that consumption processes were important for reducing NO3-N export even during winter ROS events. © 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/83696
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: Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, Canada; Department of Geography, Trent University, 1600 West Bank Drive, Peterborough, ON, Canada; Environmental and Resource Studies, Trent University, 1600 West Bank Drive, Peterborough, ON, Canada; Department of Geography, University of Winnipeg, 515 Portage Ave, Winnipeg, MB, Canada
Recommended Citation:
Casson N.J.,Eimers M.C.,Watmough S.A.. Controls on soil nitrification and stream nitrate export at two forested catchments[J]. Biogeochemistry,2014-01-01,121(2)