Journal article
Restored and reference coastal wetlands emit elevated levels of methane after an extreme rainfall event, but continue to provide climate benefits
Environmental Research Letters, Vol.Advanced access
16-Jun-2026
Abstract
Restoration of coastal wetlands provides climate adaptation and mitigation benefits. However, there is still limited information on the effects of climate change on restoration projects. We assessed the changes in soil greenhouse gas fluxes (GHG; methane, CH4, carbon dioxide, CO2, and nitrous oxide, N2O) on a site previously used for sugarcane production, and currently undergoing tidal reinstatement in subtropical Australia. Simultaneously, we sampled two natural reference mangrove sites. Sampling was conducted over three years, encompassing summer and winter seasons, before and after tidal reinstatement, and after an extreme rainfall event. After cessation of agriculture and before tidal reinstatement, GHG emissions at the restoration site were low and similar to those at the reference sites. Nine months after tidal reinstatement, soil conductivity increased from below detection limits to 5.9 ± 2.3 dS m-1, and surface soil organic carbon increased by 38%, while GHG emissions remained low. After the cyclone and the extreme rainfall event, a large peak in CH4 emissions was measured at the restoration site (3,661 ± 1,719 µg m-2 hr-1) and at one reference site (7,588 ± 2,193 µg m-2 hr-1); small N2O uptakes were also recorded in the restoration (-2.2 ± 0.5 µg m-2 hr-1) and reference sites ( -0.7 ± 0.1 µg m-2 hr-1). The fluxes were associated with prolonged freshwater flooding and low soil oxygen. After the waters receded, the emissions returned to baseline levels. Despite the elevated emissions from years with extreme rainfall (1.5 Mg CO2eq ha-1 yr-1), these are still much lower than those from alternative agricultural land uses. Thus, despite the extreme rainfall event, this blue carbon project continues to provide climate benefits.
Details
- Title
- Restored and reference coastal wetlands emit elevated levels of methane after an extreme rainfall event, but continue to provide climate benefits
- Authors
- Maria Fernanda Adame (Corresponding Author) - Griffith UniversityNaima Iram - Griffith UniversityJasmine Hall - Griffith UniversityNicholas James Grundy - Griffith UniversityAlex Pearse - The University of QueenslandVicki Bennion - The University of QueenslandCatherine E Lovelock - The University of QueenslandAshley Rummell - University of the Sunshine CoastSonia Marshall - Sunshine Coast Council (Australia)Graham Webb - Sunshine Coast Council (Australia)William Glamore - UNSW SydneyGareth R L Chalmers - University of the Sunshine CoastAndrew Olds - University of the Sunshine CoastHeather Keith - Griffith UniversityJames C Smart - Griffith University
- Publication details
- Environmental Research Letters, Vol.Advanced access
- Publisher
- Institute of Physics Publishing Ltd.
- DOI
- 10.1088/1748-9326/ae7e0b
- ISSN
- 1748-9326
- Copyright note
- Everyone is permitted to use all or part of the original content in this article, provided that they adhere to all the terms of the licence https://creativecommons.org/licences/by/4.0
- Grant note
- This project was funded by the Sunshine Coast Council, Queensland, Australia, and the Department of Climate Change, Energy, the Environment and Water, Australian Government.
- Organisation Unit
- School of Health - Biomedicine; K'gari Research Cluster; School of Science, Technology and Engineering
- Language
- English
- Record Identifier
- 991240799902621
- Output Type
- Journal article
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