DOI: 10.5194/hess-21-2035-2017
Scopus记录号: 2-s2.0-85017528678
论文题名: Changes in dissolved organic matter quality in a peatland and forest headwater stream as a function of seasonality and hydrologic conditions
作者: Broder T ; , Knorr K ; -H ; , Biester H
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2017
卷: 21, 期: 4 起始页码: 2035
结束页码: 2051
语种: 英语
Scopus关键词: Aquatic ecosystems
; Biogeochemistry
; Biological materials
; Drought
; Dynamics
; Forestry
; Groundwater
; Organic compounds
; Wetlands
; Dissolved organic matters
; Dynamics and control
; Excitation emission matrices
; Headwater stream
; Hydrologic conditions
; Microbial activities
; Organic materials
; Temporal variability
; Quality control
; concentration (composition)
; discharge
; dissolved organic matter
; drought
; groundwater
; groundwater-surface water interaction
; headwater
; microbial activity
; ombrotrophic environment
; outflow
; peatland
; riparian zone
; seasonality
; snowmelt
英文摘要: Peatlands and peaty riparian zones are major sources of dissolved organic matter (DOM), but are poorly understood in terms of export dynamics and controls thereof. Thereby quality of DOM affects function and behavior of DOM in aquatic ecosystems, but DOM quality can also help to track DOM sources and their export dynamics under specific hydrologic preconditions. The objective of this study was to elucidate controls on temporal variability in DOM concentration and quality in stream water draining a bog and a forested peaty riparian zone, particularly considering drought and storm flow events. DOM quality was monitored using spectrofluorometric indices for aromaticity (SUVA254), apparent molecular size (SR) and precursor organic material (FI), as well as PARAFAC modeling of excitation emission matrices (EEMs). Indices for DOM quality exhibited major changes due to different hydrologic conditions, but patterns were also dependent on season. Stream water at the forested site with mineral, peaty soils generally exhibited higher variability in DOM concentrations and quality compared to the outflow of an ombrotrophic bog, where DOM was less susceptible to changes in hydrologic conditions. During snowmelt and spring events, near-surface protein-like DOM pools were exported. A microbial DOM fraction originating from groundwater and deep peat layers was increasing during drought, while a strongly microbially altered DOM fraction was also exported by discharge events with dry preconditions at the forested site. This might be due to accelerated microbial activity in the peaty riparian zone of the forested site under these preconditions. Our study demonstrated that DOM export dynamics are not only a passive mixing of different hydrological sources, but monitoring studies have to consider that DOM quality depends on hydrologic preconditions and season. Moreover, the forested peaty riparian zone generated the most variability in headwater DOM quantity and quality, as could be tracked by the used spectrofluorometric indices. © 2017 The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79198
Appears in Collections: 气候变化事实与影响
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作者单位: IGÖ, Umweltgeochemie, TU Braunschweig, Langer Kamp 19c, Braunschweig, Germany; ILÖK Hydrologie, WWU Münster, Heisenbergstr. 2, Münster, Germany
Recommended Citation:
Broder T,, Knorr K,-H,et al. Changes in dissolved organic matter quality in a peatland and forest headwater stream as a function of seasonality and hydrologic conditions[J]. Hydrology and Earth System Sciences,2017-01-01,21(4)