Tropical wet season runoff mobilises younger carbon in rainforest streams but older carbon in agricultural streams

Duvert, Clément; Solano, Vanessa; Cendón, Dioni I.; Ulloa-Cedamanos, Francesco; McDonough, Liza K.; Spencer, Robert G. M.; Munksgaard, Niels C.; Hutley, Lindsay B.; Moquet, Jean-Sébastien; Butman, David E.

doi:10.5194/bg-23-1755-2026

Articles | Volume 23, issue 5

https://doi.org/10.5194/bg-23-1755-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-23-1755-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 23, issue 5

Research article

|

04 Mar 2026

Research article |

| 04 Mar 2026

Tropical wet season runoff mobilises younger carbon in rainforest streams but older carbon in agricultural streams

Clément Duvert, Vanessa Solano, Dioni I. Cendón, Francesco Ulloa-Cedamanos, Liza K. McDonough, Robert G. M. Spencer, Niels C. Munksgaard, Lindsay B. Hutley, Jean-Sébastien Moquet, and David E. Butman

Supplement

https://doi.org/10.5194/bg-23-1755-2026-supplement

Data sets

Dataset: stream carbon age in the Australian humid tropics Clément Duvert https://www.hydroshare.org/resource/c5e20d5ffe5441e2bf54ba0561fb4dd4/

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Short summary

This study examines the age and composition of carbon in tropical streams. We find that dissolved organic carbon (DOC) is centuries to millennia old, while dissolved inorganic carbon (DIC) is consistently younger, indicating a decoupling between the two. DOC age varies seasonally, with rainforest streams exporting younger DOC during high flow, while agricultural streams mobilise older DOC. Our results suggest land conversion alters carbon export, potentially worsening with climate change.