Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

An unexpected source of CO2 and CH4 emissions: a case of littoral zones of small wetlands during the growing season

Gang Li , Shengming Dong, Hao Wang, Xin Wang, Linjiang Xie, Lei Quan, Emily Hosea, Ying Chen, Wei Nie

Abstract

Context. Freshwater ecosystems significantly influence global carbon budgets from greenhouse gas (GHG) emission. However, GHG emissions from littoral zones of small wetlands remain understudied. Aims and methods. Carbon dioxide (CO2) and methane (CH4) emissions from littoral zones to the atmospheric of small wetlands were measured during the growing season (from May to October) by a cavity-enhanced absorption technique. Water vapor (H2O), atmospheric pressure (AP), wind speed (WS), soil pH, air temperature (AT), and -5 cm soil temperature (ST) were also investigated. Key results. The mean emission rate was 9.94 ± 0.27 g CO2 eq m-2 d-1 with 18.24 ± 0.40 g CO2 eq m-2 d-1 of CO2 and 0.26 ± 0.04 g CO2 eq m-2 d-1 of CH4. The mean CO2: CH4 ratio was 1.84. Except for WS and soil pH, WS, AT, and ST showed significant non-linear relationships with both CO2 and CH4 fluxes. Conclusion. This study demonstrated that littoral zones of small wetlands can play an unexpected major role in the C cycle budget and should be included in GHG inventories. In the future, GHG emissions from micro wetlands could be not neglected as a carbon source and should be included in GHG inventories.

MF24269  Accepted 02 August 2025

© CSIRO 2025