Logo image
Back
Restored coastal wetlands emit high levels of methane after a cyclone, but remain carbon sinks
Conference presentation - Abstract   Open access   Peer reviewed

Restored coastal wetlands emit high levels of methane after a cyclone, but remain carbon sinks

Fernanda Adame, Naima Iram, Alex Pearse, Jasmine Hall, Vicki Bennion, Catherine E Lovelock, Ashley Rummell, Sonia Marshall, Graham Webb, Will Glamore, …
EGU26-15877
European Geosciences Union (EGU) General Assembly, 2026 (Vienna, Austria, 03-May-2026–08-May-2026)
EGU General Assembly
2026
DOI: https://doi.org/10.5194/egusphere-egu26-15877
docx
Adame et al 2026 Restored coastal wetlands emit high levels of methane after a cyclone EGU Vienna 202614.97 kBDownloadView
Accepted Version Open Access CC BY V4.0
pdf
Abstract EGU26-1587746.02 kBDownloadView
Published Version Open Access CC BY V4.0

Abstract

Greenhouse gas inventories and fluxes Environmental rehabilitation and restoration
Restoration of coastal wetlands provides climate adaptation and mitigation benefits. However, there is still limited information on the effects of climate change-driven events 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 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 the landfall of a cyclone. Before tidal reinstatement, GHG emissions at the restoration site were low and similar to those from the reference sites. After tidal reinstatement, soil conductivity increased from zero to 5.9 ± 2.3 dS m-1, and the soil organic carbon increased by 38%, while GHG emissions remained low. After the tropical storm, a large peak in CH4 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 reduced soil conditions (-0.3 ± 12 mV and -151 ± 96 mV, respectively) caused by extreme rainfall. Nevertheless, the emissions from this event did not undermine the carbon sink potential of the restoration project, whose annual emissions (0.8 Mg CO2eq ha-1 yr-1), even for years with cyclones (1.5 Mg CO2eq ha-1 yr-1), remained lower than those from the former agricultural land use (2.6 Mg CO2eq ha-1 yr-1). Climate change will increase the likelihood of extreme rainfall events; however, mangrove restoration projects are likely to remain carbon sinks.

Details

Metrics

1 Record Views
Logo image