Greenhouse gas fluxes in a managed floodplain forest in the Amazon estuary

Aroni M.F.; Cattanio J.H.; Jardim M.A.G.; Vasconcelos S.S.; de Carvalho C.J.R.; de Morais R.S.; Maia E.T. · Agricultural and Forest Meteorology (2026) · DOI: 10.1016/j.agrformet.2025.110979

Resumen

The exchange of carbon dioxide (CO2) and methane (CH4) between the soil and the atmosphere in the Amazonian estuarine forests remains poorly quantified, obscuring their role in the greenhouse effect. However, the spatial and temporal variability of these gases needs to be better understood, mainly because of the constant occurrence of floods in this ecosystem. This is the first annual study that uses the closed dynamic chamber method to quantify CO2 and CH4 fluxes in relation to floristic composition and environmental variables in a floodplain forest in the Amazon estuary. The average soil flux was 13.60 g CO2 m-2 d-1 and 176.92 mg CH4 m-2 d-1, both presenting spatial and temporal variations. Soil CO2 flux was higher in the high topography areas and in the rainy season, and the CH4 flux was higher in the low topography areas and also in the rainy season. Greenhouse gas fluxes from soil in the Amazon floodplain are controlled by topography, which influences key determinants such as moisture (as water table height) soil temperature, and the soil carbon content. In this sense, the balance between carbon production and consumption depends on the hydrological conditions and the duration of floods, which can change under conditions of climate change.

Instituciones: Universidad Nacional del Altiplano