DOI: 10.1007/s10533-017-0404-z
Scopus记录号: 2-s2.0-85037657715
论文题名: Exploring dissolved organic carbon cycling at the stream–groundwater interface across a third-order, lowland stream network
作者: Ruhala S.S. ; Zarnetske J.P. ; Long D.T. ; Lee-Cullin J.A. ; Plont S. ; Wiewiora E.R.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2018
卷: 137, 期: 2018-01-02 起始页码: 105
结束页码: 126
语种: 英语
英文关键词: DOC
; Network scale
; Stream carbon cycling
; Streams
; Stream–groundwater interactions
Scopus关键词: carbon cycle
; concentration (composition)
; data set
; dissolved organic carbon
; groundwater-surface water interaction
; microbial activity
; network analysis
; stream
; watershed
; Michigan
; United States
英文摘要: The stream–groundwater interface (SGI) is thought to be an important location within stream networks for dissolved organic carbon (DOC) processing (e.g., degradation, removal), since it is considered a hotspot for microbial activity and biogeochemical reactions. This research is one of the first attempts to collect and assess DOC conditions at the SGI across a stream network—an entire third-order, lowland watershed in Michigan, USA. We present an initial exploration of this unique data set and highlight some of the challenges when working at these scales. Overall, our results show that SGI DOC conditions are complex at the network scale and do not conform to predictions based upon previous point- and small-scale studies. We found no strong pattern of DOC removal within the SGI at the network scale even after using chloride and temperature as natural tracers to differentiate between hydrological processes and biogeochemical reactions influencing DOC cycling. Instead, trends in DOC quantity and molecular qualities suggest that potential biotic reactions, including aerobic microbial respiration, had an influence on DOC concentrations at only some of the sites, while physical mixing of ground and stream surface waters appears to explain the majority of the observed changes in DOC concentrations at other sites. In addition, results show that neither SGI sites indicating DOC removal nor DOC molecular quality shifts measured correlated with stream order. It did reveal that DOC variability across surface water, groundwater, and the SGI locations was consistently greatest in the shallow sediments of the SGI, demonstrating that the SGI is a systematically distinct location for DOC conditions in the watershed. Our empirical stream network-scale SGI data are some of the first that are compatible with recently developed process-based, network-scale, SGI models. Our results indicate that these process-based models may not accurately represent SGI exchange of lowland, groundwater discharge-dominated streams like the one in this study. Lastly, this study shows that new methods are needed to achieve the goal of making and linking SGI observations to network-scale biogeochemical processes and theory. To help develop these methods we provide a discussion of the approach we used (i.e., “lessons-learned”) that might become the basis for systematic data analysis of SGI porewaters in future, network-wide biogeochemical studies of the SGI. © 2017, Springer International Publishing AG, part of Springer Nature. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83192
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 Earth and Environmental Sciences, Michigan State University, 288 Farm Lane, Natural Sciences Building, Room 207, East Lansing, MI, United States
Recommended Citation:
Ruhala S.S.,Zarnetske J.P.,Long D.T.,et al. Exploring dissolved organic carbon cycling at the stream–groundwater interface across a third-order, lowland stream network[J]. Biogeochemistry,2018-01-01,137(2018-01-02)