Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment
Streams are important sources of carbon to the atmosphere, though knowing whether they merely outgas terrestrially derived carbon dioxide or mineralize terrestrial inputs of dissolved organic matter (DOM) is still a big challenge in ecology. The objective of this study was to investigate the infl...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2018-03-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://www.hydrol-earth-syst-sci.net/22/1897/2018/hess-22-1897-2018.pdf |
| _version_ | 1818997674109566976 |
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| author | S. Bernal S. Bernal A. Lupon A. Lupon N. Catalán S. Castelar E. Martí |
| author_facet | S. Bernal S. Bernal A. Lupon A. Lupon N. Catalán S. Castelar E. Martí |
| author_sort | S. Bernal |
| collection | DOAJ |
| description | Streams are important sources of carbon to the atmosphere, though knowing whether
they merely outgas terrestrially derived carbon dioxide or mineralize
terrestrial inputs of dissolved organic matter (DOM) is still a big challenge
in ecology. The objective of this study was to investigate the influence of
riparian groundwater (GW) and in-stream processes on the temporal pattern of
stream DOM concentrations and quality in a forested headwater stream, and
whether this influence differed between the leaf litter fall (LLF) period and
the remaining part of the year (non-LLF). The spectroscopic indexes
(fluorescence index, biological index, humification index, and parallel factor analysis
components) indicated that DOM had an eminently protein-like character and
was most likely originated from microbial sources and recent biological
activity in both stream water and riparian GW. However, paired samples of
stream water and riparian GW showed that dissolved organic carbon (DOC) and
nitrogen (DON) concentrations as well as the spectroscopic character of DOM
differed between the two compartments throughout the year. A simple mass
balance approach indicated that in-stream processes along the reach
contributed to reducing DOC and DON fluxes by 50 and 30 %, respectively.
Further, in-stream DOC and DON uptakes were unrelated to each other,
suggesting that these two compounds underwent different biogeochemical
pathways. During the LLF period, stream DOC and DOC : DON ratios were
higher than during the non-LLF period, and spectroscopic indexes suggested a
major influence of terrestrial vegetation on stream DOM. Our study highlights
that stream DOM is not merely a reflection of riparian GW entering the stream
and that headwater streams have the capacity to internally produce,
transform, and consume DOM. |
| first_indexed | 2024-12-20T21:49:23Z |
| format | Article |
| id | doaj.art-e404c9ed6dc544dc8455f05fe39b174c |
| institution | Directory Open Access Journal |
| issn | 1027-5606 1607-7938 |
| language | English |
| last_indexed | 2024-12-20T21:49:23Z |
| publishDate | 2018-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Hydrology and Earth System Sciences |
| spelling | doaj.art-e404c9ed6dc544dc8455f05fe39b174c2022-12-21T19:25:36ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382018-03-01221897191010.5194/hess-22-1897-2018Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchmentS. Bernal0S. Bernal1A. Lupon2A. Lupon3N. Catalán4S. Castelar5E. Martí6Integrative Freshwater Ecology Group, Center for Advanced Studies of Blanes (CEAB-CSIC), Blanes, 17300, SpainDepartament de Biologia Evolutiva, Ecologia i Ciències Ambientals (BEECA), Universitat de Barcelona, Barcelona, 08028, SpainDepartament de Biologia Evolutiva, Ecologia i Ciències Ambientals (BEECA), Universitat de Barcelona, Barcelona, 08028, SpainDepartment of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, 90183, SwedenDepartment of Resources and Ecosystems, ICRA, Catalan Institute for Water Research, Girona, 17003, SpainIntegrative Freshwater Ecology Group, Center for Advanced Studies of Blanes (CEAB-CSIC), Blanes, 17300, SpainIntegrative Freshwater Ecology Group, Center for Advanced Studies of Blanes (CEAB-CSIC), Blanes, 17300, SpainStreams are important sources of carbon to the atmosphere, though knowing whether they merely outgas terrestrially derived carbon dioxide or mineralize terrestrial inputs of dissolved organic matter (DOM) is still a big challenge in ecology. The objective of this study was to investigate the influence of riparian groundwater (GW) and in-stream processes on the temporal pattern of stream DOM concentrations and quality in a forested headwater stream, and whether this influence differed between the leaf litter fall (LLF) period and the remaining part of the year (non-LLF). The spectroscopic indexes (fluorescence index, biological index, humification index, and parallel factor analysis components) indicated that DOM had an eminently protein-like character and was most likely originated from microbial sources and recent biological activity in both stream water and riparian GW. However, paired samples of stream water and riparian GW showed that dissolved organic carbon (DOC) and nitrogen (DON) concentrations as well as the spectroscopic character of DOM differed between the two compartments throughout the year. A simple mass balance approach indicated that in-stream processes along the reach contributed to reducing DOC and DON fluxes by 50 and 30 %, respectively. Further, in-stream DOC and DON uptakes were unrelated to each other, suggesting that these two compounds underwent different biogeochemical pathways. During the LLF period, stream DOC and DOC : DON ratios were higher than during the non-LLF period, and spectroscopic indexes suggested a major influence of terrestrial vegetation on stream DOM. Our study highlights that stream DOM is not merely a reflection of riparian GW entering the stream and that headwater streams have the capacity to internally produce, transform, and consume DOM.https://www.hydrol-earth-syst-sci.net/22/1897/2018/hess-22-1897-2018.pdf |
| spellingShingle | S. Bernal S. Bernal A. Lupon A. Lupon N. Catalán S. Castelar E. Martí Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment Hydrology and Earth System Sciences |
| title | Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment |
| title_full | Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment |
| title_fullStr | Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment |
| title_full_unstemmed | Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment |
| title_short | Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment |
| title_sort | decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment |
| url | https://www.hydrol-earth-syst-sci.net/22/1897/2018/hess-22-1897-2018.pdf |
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