DOI: 10.1029/2017JG004109
Scopus记录号: 2-s2.0-85049827862
论文题名: Evaluating Controls on Nutrient Retention and Export in Wide and Narrow Valley Segments of a Mountain River Corridor
作者: Wegener P. ; Covino T. ; Rhoades C.
刊名: Journal of Geophysical Research: Biogeosciences
ISSN: 21698953
出版年: 2018
卷: 123, 期: 6 起始页码: 1817
结束页码: 1826
语种: 英语
英文关键词: biogeochemistry
; geomorphology
; nitrogen saturation
; nutrient retention
; riparian
; stream-groundwater exchange
Scopus关键词: biological uptake
; concentration (composition)
; experimental study
; floodplain
; hillslope
; mass balance
; nitrate
; nitrogen
; nutrient enrichment
; riparian zone
; saturation
; stream
; Colorado
; Rocky Mountain National Park
; United States
英文摘要: Over the past few decades, nitrate-nitrogen (NO3-N) concentrations have increased within streams of the central Rockies, a pattern linked to regional N deposition trends. As NO3-N concentrations increase, in-stream biological demand may become saturated and stream N export may increase. In mountain landscapes, streams generally flow through steep, narrow valleys with limited riparian area and strong stream-hillslope connectivity. Interspersed between the narrow valleys are wide segments where substantial floodplain riparian areas can develop. Here, we coupled measures of stream reach NO3-N flux balances with nutrient enrichment experiments along two stream reaches of contrasting valley morphology in Rocky Mountain National Park. The stream reaches were (1) a narrow valley segment with limited floodplain riparian area and (2) a longitudinally adjacent (directly downstream) wide valley segment with extensive floodplain riparian area. We found that in-stream biological uptake of added NO3-N was limited in both segments, presumably as a consequence of saturating conditions. Assessment of mass flux indicated that the narrow valley segment was a consistent source of water and NO3-N across flow states, while the wide segment was a sink at high flow and a source at low flow. Due to low in-stream biological retention, gross gains and losses of water and NO3-N to and from the stream exerted primary constraint on segment mass balances. Our results suggest that the exchange of water and nutrients between the stream and adjacent landscape can exert strong control on reach-scale nutrient export, particularly in streams experiencing or approaching N saturation. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113761
Appears in Collections: 气候减缓与适应
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作者单位: Ecosystem Science and Sustainability Department, Colorado State University, Fort Collins, CO, United States; Natural Resources Ecology Laboratory, Colorado State University, Fort Collins, CO, United States; USFS Rocky Mountain Research Station, Fort Collins, CO, United States
Recommended Citation:
Wegener P.,Covino T.,Rhoades C.. Evaluating Controls on Nutrient Retention and Export in Wide and Narrow Valley Segments of a Mountain River Corridor[J]. Journal of Geophysical Research: Biogeosciences,2018-01-01,123(6)