DOI: 10.1002/2017JG003960
Scopus记录号: 2-s2.0-85045507954
论文题名: Regional Groundwater and Storms Are Hydrologic Controls on the Quality and Export of Dissolved Organic Matter in Two Tropical Rainforest Streams, Costa Rica
作者: Osburn C.L. ; Oviedo-Vargas D. ; Barnett E. ; Dierick D. ; Oberbauer S.F. ; Genereux D.P.
刊名: Journal of Geophysical Research: Biogeosciences
ISSN: 21698953
出版年: 2018
卷: 123, 期: 3 起始页码: 850
结束页码: 866
语种: 英语
英文关键词: CDOM
; DOM
; stable carbon isotopes
; stream
Scopus关键词: absorbance
; baseflow
; carbon isotope
; dissolved organic matter
; fluorescence
; flux measurement
; groundwater
; groundwater flow
; lowland environment
; qualitative analysis
; rainforest
; runoff
; stable isotope
; storm
; stream
; throughfall
; tropical forest
; watershed
; Costa Rica
英文摘要: A paired-watershed approach was used to compare the quality and fluxes of dissolved organic matter (DOM) during stormflow and baseflow in two lowland tropical rainforest streams located in northeastern Costa Rica. The Arboleda stream received regional groundwater (RGW) flow, whereas the Taconazo stream did not. DOM quality was assessed with absorbance and fluorescence and stable carbon isotope (δ13C-DOC) values. RGW DOM lacked detectable fluorescence and had specific ultraviolet absorption (SUVA254) and absorbance slope ratio (SR) values consistent with low aromaticity and low molecular weight material, respectively. We attributed these properties to microbial degradation and sorption of humic DOM to mineral surfaces during transport through bedrock. SUVA254 values were lower and SR values were higher in the Arboleda stream during baseflow compared to the Taconazo stream, presumably due to dilution by RGW. However, no significant difference in SUVA254 or SR occurred between the streams during stormflow. SUVA254 was negatively correlated to δ13C-DOC (r2 = 0.61, P < 0.001), demonstrating a strong linkage between stream DOM characteristics and the relative amounts of RGW flow and local watershed runoff containing soil and throughfall C sources. Mean DOC export from the Taconazo stream during the study period was 2.62 ± 0.39 g C m−2 year−1, consistent with other tropical streams, yet mean DOC export from the Arboleda stream was 13.79 ± 2.07 g C m−2 year−1, one of the highest exports reported and demonstrating a substantial impact of old RGW from outside the watershed boundary can have on surface water carbon cycling. ©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/114344
Appears in Collections: 气候减缓与适应
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作者单位: Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC, United States; Stroud Water Research Center, Avondale, PA, United States; Department of Biological Sciences, Florida International University, Miami, FL, United States
Recommended Citation:
Osburn C.L.,Oviedo-Vargas D.,Barnett E.,et al. Regional Groundwater and Storms Are Hydrologic Controls on the Quality and Export of Dissolved Organic Matter in Two Tropical Rainforest Streams, Costa Rica[J]. Journal of Geophysical Research: Biogeosciences,2018-01-01,123(3)