DOI: 10.1002/2016GB005388
Scopus记录号: 2-s2.0-84977499554
论文题名: Dynamic biogeochemical controls on river pCO2 and recent changes under aggravating river impoundment: An example of the subtropical Yangtze River
作者: Liu S ; , Lu X ; X ; , Xia X ; , Zhang S ; , Ran L ; , Yang X ; , Liu T
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2016
卷: 30, 期: 6 起始页码: 880
结束页码: 897
语种: 英语
英文关键词: autotrophy
; pCO2
; reservoir
; river
; river organic carbon
Scopus关键词: allochthon
; autotrophy
; biogeochemistry
; chlorophyll a
; dissolved oxygen
; heterotrophy
; impoundment
; organic carbon
; spatial distribution
; subtropical region
; supersaturation
; total organic carbon
; tributary
; water chemistry
; water column
; China
; Yangtze River
英文摘要: This paper highlights two aspects of the dynamic biogeochemical controls of riverine pCO2 in an increasingly impounded large subtropical river (the Yangtze): the terrestrial dominance through internal respiration of land-derived organic carbon and the influence of increased autotrophic activity in impounded areas on river pCO2. River pCO2 and total organic carbon (TOC) increase downstream on the main stem (pCO2: 528–1703 µatm; TOC: 137–263 µmol/L) and vary significantly among tributaries (464–3300 µatm; TOC: 109–340 µmol/L). pCO2 displays larger spatial variability than temporal variability and is spatially correlated with river organic carbon across the river (p < 0.05–0.0001, seasonally independent). pCO2 is also negatively correlated with dissolved oxygen (r2 = 0.46, p < 0.0001). Respiration of allochthonous organic carbon in water column is concluded as an essential source of CO2 supersaturation and river heterotrophy. However, significant benthic respiration and/or direct soil CO2 transport (e.g., via groundwater, ~80%) exist at the same time. The temporal and spatial distribution of POC compositional characteristics and chlorophyll a indicate the dominant control of terrestrial processes (e.g., organic matter transport and soil erosion) on the river pCO2 biogeochemistry, especially in warm seasons. Increased autotrophy and significant pCO2 decrease (>60%) do occur in impounded areas (especially in nutrient-rich rivers), but the decrease is mostly temporal and regional (~8% of the data points are significantly influenced, all from the upper reach and/or major tributaries). The paper concludes that terrestrial influence still dominates the pCO2 biogeochemistry in this increasingly intercepted and regulated river system. ©2016. 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/77846
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Geography, National University of Singapore, Kent Ridge, Singapore; College of Environment and Resources, Inner Mongolia University, Hohhot, China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China; College of Water Sciences, Beijing Normal University, Beijing, China; State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
Recommended Citation:
Liu S,, Lu X,X,et al. Dynamic biogeochemical controls on river pCO2 and recent changes under aggravating river impoundment: An example of the subtropical Yangtze River[J]. Global Biogeochemical Cycles,2016-01-01,30(6)