Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis
Southeast Asian peatlands supply ∼10 % of the global flux of dissolved organic carbon (DOC) from land to the ocean, but the biogeochemical cycling of this peat-derived DOC in coastal environments is still poorly understood. Here, we use fluorescence spectroscopy and parallel factor (PARAFAC) analysi...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2019
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/83523 http://hdl.handle.net/10220/49763 |
| _version_ | 1811695490867134464 |
|---|---|
| author | Zhou, Yongli Martin, Patrick Müller, Moritz |
| author2 | Asian School of the Environment |
| author_facet | Asian School of the Environment Zhou, Yongli Martin, Patrick Müller, Moritz |
| author_sort | Zhou, Yongli |
| collection | NTU |
| description | Southeast Asian peatlands supply ∼10 % of the global flux of dissolved organic carbon (DOC) from land to the ocean, but the biogeochemical cycling of this peat-derived DOC in coastal environments is still poorly understood. Here, we use fluorescence spectroscopy and parallel factor (PARAFAC) analysis to distinguish different fractions of dissolved organic matter (DOM) in peat-draining rivers, estuaries and coastal waters of Sarawak, Borneo. The terrigenous fractions showed high concentrations at freshwater stations within the rivers, and conservative mixing with seawater across the estuaries. The autochthonous DOM fraction, in contrast, showed low concentrations throughout our study area at all salinities. The DOM pool was also characterized by a high degree of humification in all rivers and estuaries up to salinities of 25. These results indicate a predominantly terrestrial origin of the riverine DOM pool. Only at salinities > 25 did we observe an increase in the proportion of autochthonous relative to terrestrial DOM. Natural sunlight exposure experiments with river water and seawater showed high photolability of the terrigenous DOM fractions, suggesting that photodegradation may account for the observed changes in the DOM composition in coastal waters. Nevertheless, based on our fluorescence data, we estimate that at least 20 %–25 % of the DOC at even our most marine stations (salinity > 31) was terrestrial in origin, indicating that peatlands likely play an important role in the carbon biogeochemistry of Southeast Asian shelf seas. |
| first_indexed | 2024-10-01T07:24:18Z |
| format | Journal Article |
| id | ntu-10356/83523 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:24:18Z |
| publishDate | 2019 |
| record_format | dspace |
| spelling | ntu-10356/835232023-02-28T16:41:56Z Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis Zhou, Yongli Martin, Patrick Müller, Moritz Asian School of the Environment Fluorescence Spectroscopy Science::Geology DOM Pool Southeast Asian peatlands supply ∼10 % of the global flux of dissolved organic carbon (DOC) from land to the ocean, but the biogeochemical cycling of this peat-derived DOC in coastal environments is still poorly understood. Here, we use fluorescence spectroscopy and parallel factor (PARAFAC) analysis to distinguish different fractions of dissolved organic matter (DOM) in peat-draining rivers, estuaries and coastal waters of Sarawak, Borneo. The terrigenous fractions showed high concentrations at freshwater stations within the rivers, and conservative mixing with seawater across the estuaries. The autochthonous DOM fraction, in contrast, showed low concentrations throughout our study area at all salinities. The DOM pool was also characterized by a high degree of humification in all rivers and estuaries up to salinities of 25. These results indicate a predominantly terrestrial origin of the riverine DOM pool. Only at salinities > 25 did we observe an increase in the proportion of autochthonous relative to terrestrial DOM. Natural sunlight exposure experiments with river water and seawater showed high photolability of the terrigenous DOM fractions, suggesting that photodegradation may account for the observed changes in the DOM composition in coastal waters. Nevertheless, based on our fluorescence data, we estimate that at least 20 %–25 % of the DOC at even our most marine stations (salinity > 31) was terrestrial in origin, indicating that peatlands likely play an important role in the carbon biogeochemistry of Southeast Asian shelf seas. MOE (Min. of Education, S’pore) Published version 2019-08-23T05:06:31Z 2019-12-06T15:24:48Z 2019-08-23T05:06:31Z 2019-12-06T15:24:48Z 2019 Journal Article Zhou, Y., Martin, P., & Müller, M. (2019). Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis. Biogeosciences, 16(13), 2733-2749. doi:10.5194/bg-16-2733-2019 1726-4170 https://hdl.handle.net/10356/83523 http://hdl.handle.net/10220/49763 10.5194/bg-16-2733-2019 en Biogeosciences https://doi.org/10.21979/N9/RCYCIT © 2019 Author(s). This work is distributed under the Creative Commons Attribution 4.0 License. 17 p. application/pdf |
| spellingShingle | Fluorescence Spectroscopy Science::Geology DOM Pool Zhou, Yongli Martin, Patrick Müller, Moritz Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis |
| title | Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis |
| title_full | Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis |
| title_fullStr | Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis |
| title_full_unstemmed | Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis |
| title_short | Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis |
| title_sort | composition and cycling of dissolved organic matter from tropical peatlands of coastal sarawak borneo revealed by fluorescence spectroscopy and parallel factor analysis |
| topic | Fluorescence Spectroscopy Science::Geology DOM Pool |
| url | https://hdl.handle.net/10356/83523 http://hdl.handle.net/10220/49763 |
| work_keys_str_mv | AT zhouyongli compositionandcyclingofdissolvedorganicmatterfromtropicalpeatlandsofcoastalsarawakborneorevealedbyfluorescencespectroscopyandparallelfactoranalysis AT martinpatrick compositionandcyclingofdissolvedorganicmatterfromtropicalpeatlandsofcoastalsarawakborneorevealedbyfluorescencespectroscopyandparallelfactoranalysis AT mullermoritz compositionandcyclingofdissolvedorganicmatterfromtropicalpeatlandsofcoastalsarawakborneorevealedbyfluorescencespectroscopyandparallelfactoranalysis |