Determining methane uptake in tropical agroforestry soils: a case for inclusion in REDD+

Abstract

This study aims to measure possible seasonal methane (CH4) fluxes in tropical agroforestry soils to enhance the case for agroforestry’s inclusion in the Reducing Emissions from Deforestation and Forest Degradation (REDD+) program. The role of CH4 in the REDD+ program is currently uncertain. Air samples and environmental variables from the soil-atmosphere interface of the Maya Mountain Research Farm in southern Belize were collected three times per week throughout April and July of 2019. Samples were analyzed using the static chamber and gas chromatography method. The average CH4 flux for the dry season was − 0.02 mg CH4 m−2 h−1 and − 0.03 mg CH4 m−2 h−1 for the wet season, with negative values indicative of uptake. There was a negative correlation between CH4 flux and rainfall in the dry season and a positive correlation in the wet season, indicating that CH4 uptake occurred during the dry season. However, our results show that there is not a significant pattern of CH4 uptake (at a 95% confidence limit). Given the large discrepancy in the literature regarding CH4 uptake from agroforestry soils, further investigation of CH4 fluxes from agroforestry soils is warranted. Understanding CH4 fluxes in tropical agroforestry soils are of paramount importance for agroforestry utilization as a tool for climate change mitigation through the REDD+ program.