DOI: 10.5194/hess-21-4785-2017
Scopus记录号: 2-s2.0-85030472632
论文题名: Hydrological controls on DOC nitrate resource stoichiometry in a lowland, agricultural catchment, southern UK
作者: Heppell C ; M ; , Binley A ; , Trimmer M ; , Darch T ; , Jones A ; , Malone E ; , Collins A ; L ; , Johnes P ; J ; , Freer J ; E ; , Lloyd C ; E ; M
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2017
卷: 21, 期: 9 起始页码: 4785
结束页码: 4802
语种: 英语
Scopus关键词: Agriculture
; Carbon
; Catchments
; Climate change
; Groundwater
; Land use
; Limestone
; Nitrogen
; Organic carbon
; Rivers
; Runoff
; Sandstone
; Agricultural catchments
; Agricultural landscapes
; Dissolved organic carbon
; Hydrological controls
; Hydrological regime
; Negative correlation
; Nitrate concentration
; Resource stoichiometries
; Nitrates
; agricultural catchment
; climate change
; concentration (composition)
; dissolved organic carbon
; headwater
; hydrological regime
; lowland environment
; nitrate
; nitrogen
; nutrient dynamics
; stoichiometry
; England
; Hampshire
; United Kingdom
; Wiltshire
英文摘要: The role that hydrology plays in governing the interactions between dissolved organic carbon (DOC) and nitrogen in rivers draining lowland, agricultural landscapes is currently poorly understood. In light of the potential changes to the production and delivery of DOC and nitrate to rivers arising from climate change and land use management, there is a pressing need to improve our understanding of hydrological controls on DOC and nitrate dynamics in such catchments. We measured DOC and nitrate concentrations in river water of six reaches of the lowland river Hampshire Avon (Wiltshire, southern UK) in order to quantify the relationship between BFI (BFI) and DOC: Nitrate molar ratios across contrasting geologies (Chalk, Greensand, and clay). We found a significant positive relationship between nitrate and BFI (p < 0:0001), and a significant negative relationship between DOC and BFI (p < 0:0001), resulting in a non-linear negative correlation between DOC: Nitrate molar ratio and BFI. In the Hampshire Avon, headwater reaches which are underlain by clay and characterized by a more flashy hydrological regime are associated with DOC: Nitrate ratios >5 throughout the year, whilst groundwater-dominated reaches underlain by Chalk, with a high BFI have DOC: Nitrate ratios in surface waters that are an order of magnitude lower (<0.5). Our analysis also reveals significant seasonal variations in DOC: Nitrate transport and highlights critical periods of nitrate export (e.g. winter in sub-catchments underlain by Chalk and Greensand, and autumn in drained, clay subcatchments) when DOC: Nitrate molar ratios are low, suggesting low potential for in-stream uptake of inorganic forms of nitrogen. Consequently, our study emphasizes the tight relationship between DOC and nitrate availability in agricultural catchments, and further reveals that this relationship is controlled to a great extent by the hydrological setting. © 2017 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79047
Appears in Collections: 气候变化事实与影响
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作者单位: School of Geography, Queen Mary University of London, Mile End Road, London, United Kingdom; Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom; School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, United Kingdom; Sustainable Agriculture Sciences Department, Rothamsted Research, Okehampton, United Kingdom; School of Geographical Sciences, University of Bristol, University Road, Bristol, United Kingdom; School of Chemistry, University of Bristol, Bristol, United Kingdom
Recommended Citation:
Heppell C,M,, Binley A,et al. Hydrological controls on DOC nitrate resource stoichiometry in a lowland, agricultural catchment, southern UK[J]. Hydrology and Earth System Sciences,2017-01-01,21(9)