DOI: 10.1007/s10533-017-0381-2
Scopus记录号: 2-s2.0-85029894422
论文题名: Irrigation as a fuel pump to freshwater ecosystems
作者: Matiasek S.J. ; Pellerin B.A. ; Spencer R.G.M. ; Bergamaschi B.A. ; Hernes P.J.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 136, 期: 1 起始页码: 71
结束页码: 90
语种: 英语
英文关键词: Agricultural watershed
; Amino acids
; Dissolved organic matter
; Hydrologic controls
Scopus关键词: amino acid
; biogeochemistry
; concentration (composition)
; dissolved organic carbon
; dissolved organic matter
; dissolved organic nitrogen
; freshwater ecosystem
; seasonal variation
; stream
; watershed
; California
; United States
英文摘要: We generated a detailed time series of total dissolved hydrolyzable amino acids (DHAA) in a watershed dominated by irrigated agriculture in northern California, USA to investigate the roles of hydrologic and seasonal changes on the composition of dissolved organic matter (DOM). DHAA are sensitive indicators of the degradation state and reactivity of DOM. DHAA concentrations ranged from 0.55 to 9.96 μM (median 3.51 ± 1.80 μM), with expected peaks during high-discharge storms and unexpected high values throughout the low-discharge irrigation season. Overall, summer irrigation was a critical hydrologic regime for DOM cycling since it mobilized DOM similar in concentration and reactivity to DOM released during storms. Together, irrigation and storm flows exported DOM with (1) the largest DHAA contributions to the dissolved organic carbon and the dissolved organic nitrogen pools, (2) the largest proportion of basic amino acids, and (3) the lowest degradation extent based on multiple indices. In this highly disturbed terrestrial system, UV–vis absorbance did not correlate with DHAA concentrations, while classic interpretations of common amino acid indicators (e.g., proportion of basic amino acids, degradation index, percent of non-protein amino acids) were prone to conflicting characterizations of DOM reactivity. Therefore, a new parameter (processing ratio, PR) derived from individual amino acid concentrations was developed that demonstrated a strong potential for mechanistic-driven characterization of the extent of DOM diagenesis in freshwaters. Irrigated agriculture altered stream biogeochemistry by releasing a continuous supply of reactive DOM (lowest PR values), thereby providing an additional energy source to downstream ecosystems. © 2017, Springer International Publishing AG. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83227
Appears in Collections: 气候减缓与适应 气候变化事实与影响
There are no files associated with this item.
作者单位: Department of Geological and Environmental Sciences, California State University Chico, 400 W 1st St, Chico, CA, United States; United States Geological Survey, 12201 Sunrise Valley Drive, Reston, VA, United States; Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL, United States; United States Geological Survey, Placer Hall, 6000 J Street, Sacramento, CA, United States; Department of Land, Air and Water Resources, University of California Davis, One Shields Avenue, Davis, CA, United States
Recommended Citation:
Matiasek S.J.,Pellerin B.A.,Spencer R.G.M.,et al. Irrigation as a fuel pump to freshwater ecosystems[J]. Biogeochemistry,2017-01-01,136(1)