Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/83523
Title: Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis
Authors: Zhou, Yongli
Martin, Patrick
Müller, Moritz
Keywords: Fluorescence Spectroscopy
Science::Geology
DOM Pool
Issue Date: 2019
Source: 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
Series/Report no.: Biogeosciences
Abstract: 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.
URI: https://hdl.handle.net/10356/83523
http://hdl.handle.net/10220/49763
ISSN: 1726-4170
DOI: http://dx.doi.org/10.5194/bg-16-2733-2019
Rights: © 2019 Author(s). This work is distributed under the Creative Commons Attribution 4.0 License.
metadata.item.grantfulltext: open
metadata.item.fulltext: With Fulltext
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