Cascade dams amplify molecular transformation and compositional homogenization of dissolved organic matter on the Eastern Tibetan Plateau.
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| Title: | Cascade dams amplify molecular transformation and compositional homogenization of dissolved organic matter on the Eastern Tibetan Plateau. |
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| Authors: | He, Dengming1 (AUTHOR), Wang, Wanfa1 (AUTHOR) wfwang@gzu.edu.cn, Maurischat, Philipp2 (AUTHOR), Yi, Yuanbi3 (AUTHOR), Qi, Yulin4 (AUTHOR), Hu, Xuan1 (AUTHOR), Tu, Shijun1 (AUTHOR), Yu, Shengde5 (AUTHOR), Zeng, Jie1 (AUTHOR), Wu, Qixin1 (AUTHOR), Xia, Hao6 (AUTHOR), He, Ding3 (AUTHOR), Li, Si-Liang4 (AUTHOR) |
| Source: | Water Research. Jun2026, Vol. 297, pN.PAG-N.PAG. 1p. |
| Subjects: | Dissolved organic matter, Dams, Biogeochemistry, Water pollution, Chemical processes, Hydrology, Carbon cycle |
| Geographic Terms: | Tibet (China) |
| Abstract: | • Cascade dams accelerate allochthonous dissolved organic matter (DOM) turnover. • Thermodynamic decomposition transforms DOM from labile to recalcitrant. • Warming lentic areas enhance DOM homogenization in cascade reservoirs. • Dam-induced hydrological fragmentation predicts river autochthonous DOM export. River damming globally disrupts hydrological connectivity, transforming reservoirs into critical regulators of the global carbon cycling. However, the molecular characteristics and the specific transformation processes of dissolved organic matter (DOM) in cascade reservoirs remain unclear. To address this knowledge gap, we integrated water chemistry, stable carbon isotopes, and Fourier transform ion cyclotron resonance mass spectrometry to elucidate the molecular fate of DOM across cascade river-reservoir systems on the Eastern Tibetan Plateau. Results demonstrated that cascade damming enhanced autochthonous DOM production, as estimated by a simmr-based stable-isotope mixing model, increasing the phytoplankton-derived fraction of DOM from 27 ± 10% in rivers to 31 ± 12% in cascade reservoirs (posterior mean ± SD). Simultaneously, the favorable thermodynamic condition accelerated the turnover of allochthonous DOM by enhancing both photochemical and microbial decomposition processes within the warming lentic areas. These processes amplified DOM homogenization, evidenced by a decrease in the Jaccard dissimilarity coefficient along the flow path, resulting from consuming labile fractions. Furthermore, the reduced hydrological connectivity due to dam construction facilitated the downstream transport of autochthonous DOM. It is estimated that the global export flux of autochthonous dissolved organic carbon to the oceans amounts to 141 ± 2 Tg C yr–1. Our results highlight that the global proliferation of reservoirs fundamentally alters the biogeochemical fate of DOM, with implications for regional and global carbon cycling. [Display omitted] [ABSTRACT FROM AUTHOR] |
| Copyright of Water Research is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 192588371 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Cascade dams amplify molecular transformation and compositional homogenization of dissolved organic matter on the Eastern Tibetan Plateau. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22He%2C+Dengming%22">He, Dengming</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Wang%2C+Wanfa%22">Wang, Wanfa</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> wfwang@gzu.edu.cn</i><br /><searchLink fieldCode="AR" term="%22Maurischat%2C+Philipp%22">Maurischat, Philipp</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Yi%2C+Yuanbi%22">Yi, Yuanbi</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Qi%2C+Yulin%22">Qi, Yulin</searchLink><relatesTo>4</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Hu%2C+Xuan%22">Hu, Xuan</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Tu%2C+Shijun%22">Tu, Shijun</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Yu%2C+Shengde%22">Yu, Shengde</searchLink><relatesTo>5</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Zeng%2C+Jie%22">Zeng, Jie</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Wu%2C+Qixin%22">Wu, Qixin</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Xia%2C+Hao%22">Xia, Hao</searchLink><relatesTo>6</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22He%2C+Ding%22">He, Ding</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Li%2C+Si-Liang%22">Li, Si-Liang</searchLink><relatesTo>4</relatesTo> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Water+Research%22">Water Research</searchLink>. Jun2026, Vol. 297, pN.PAG-N.PAG. 1p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Dissolved+organic+matter%22">Dissolved organic matter</searchLink><br /><searchLink fieldCode="DE" term="%22Dams%22">Dams</searchLink><br /><searchLink fieldCode="DE" term="%22Biogeochemistry%22">Biogeochemistry</searchLink><br /><searchLink fieldCode="DE" term="%22Water+pollution%22">Water pollution</searchLink><br /><searchLink fieldCode="DE" term="%22Chemical+processes%22">Chemical processes</searchLink><br /><searchLink fieldCode="DE" term="%22Hydrology%22">Hydrology</searchLink><br /><searchLink fieldCode="DE" term="%22Carbon+cycle%22">Carbon cycle</searchLink> – Name: SubjectGeographic Label: Geographic Terms Group: Su Data: <searchLink fieldCode="DE" term="%22Tibet+%28China%29%22">Tibet (China)</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: • Cascade dams accelerate allochthonous dissolved organic matter (DOM) turnover. • Thermodynamic decomposition transforms DOM from labile to recalcitrant. • Warming lentic areas enhance DOM homogenization in cascade reservoirs. • Dam-induced hydrological fragmentation predicts river autochthonous DOM export. River damming globally disrupts hydrological connectivity, transforming reservoirs into critical regulators of the global carbon cycling. However, the molecular characteristics and the specific transformation processes of dissolved organic matter (DOM) in cascade reservoirs remain unclear. To address this knowledge gap, we integrated water chemistry, stable carbon isotopes, and Fourier transform ion cyclotron resonance mass spectrometry to elucidate the molecular fate of DOM across cascade river-reservoir systems on the Eastern Tibetan Plateau. Results demonstrated that cascade damming enhanced autochthonous DOM production, as estimated by a simmr-based stable-isotope mixing model, increasing the phytoplankton-derived fraction of DOM from 27 ± 10% in rivers to 31 ± 12% in cascade reservoirs (posterior mean ± SD). Simultaneously, the favorable thermodynamic condition accelerated the turnover of allochthonous DOM by enhancing both photochemical and microbial decomposition processes within the warming lentic areas. These processes amplified DOM homogenization, evidenced by a decrease in the Jaccard dissimilarity coefficient along the flow path, resulting from consuming labile fractions. Furthermore, the reduced hydrological connectivity due to dam construction facilitated the downstream transport of autochthonous DOM. It is estimated that the global export flux of autochthonous dissolved organic carbon to the oceans amounts to 141 ± 2 Tg C yr–1. Our results highlight that the global proliferation of reservoirs fundamentally alters the biogeochemical fate of DOM, with implications for regional and global carbon cycling. [Display omitted] [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Water Research is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.watres.2026.125765 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 1 StartPage: N.PAG Subjects: – SubjectFull: Dissolved organic matter Type: general – SubjectFull: Dams Type: general – SubjectFull: Biogeochemistry Type: general – SubjectFull: Water pollution Type: general – SubjectFull: Chemical processes Type: general – SubjectFull: Hydrology Type: general – SubjectFull: Carbon cycle Type: general – SubjectFull: Tibet (China) Type: general Titles: – TitleFull: Cascade dams amplify molecular transformation and compositional homogenization of dissolved organic matter on the Eastern Tibetan Plateau. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: He, Dengming – PersonEntity: Name: NameFull: Wang, Wanfa – PersonEntity: Name: NameFull: Maurischat, Philipp – PersonEntity: Name: NameFull: Yi, Yuanbi – PersonEntity: Name: NameFull: Qi, Yulin – PersonEntity: Name: NameFull: Hu, Xuan – PersonEntity: Name: NameFull: Tu, Shijun – PersonEntity: Name: NameFull: Yu, Shengde – PersonEntity: Name: NameFull: Zeng, Jie – PersonEntity: Name: NameFull: Wu, Qixin – PersonEntity: Name: NameFull: Xia, Hao – PersonEntity: Name: NameFull: He, Ding – PersonEntity: Name: NameFull: Li, Si-Liang IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 06 Text: Jun2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 00431354 Numbering: – Type: volume Value: 297 Titles: – TitleFull: Water Research Type: main |
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