Carbon Flux in a Semi-Arid Mangrove Ecosystem in Magdalena Bay, B.C.S Mexico

Mangrove forests are among the most productive ecosystems in the world. These tropical and subtropical coastal forests provide a wide array of ecosystem services, including the ability to sequester and store large amounts of blue carbon. Rising concerns over anthropogenic CO2 emissions, have increasingly recognized mangroves for their potential in climate change mitigation programs. However, their productivity values differ considerably across environments, making it difficult to estimate carbon sequestration potential at regional levels. Additionally, most research has focused in humid and tropical latitudes, with limited studies in arid and semi-arid regions. The objectives were to study a semi-arid mangrove forest in Magdalena Bay, Baja California Sur (BCS), Mexico to quantify the average net ecosystem exchange (NEE), determine the annual carbon budget and the environmental variables driving those fluxes. Measurements were taken during 2012-2013 using the eddy covariance technique, with a daily mean of -2.45 g C m-2 d-1 and annual carbon uptake of 894 g C m-2 y-1. Temporal variations in NEE were primarily regulated by light, but air temperature and vapor pressure deficit (VPD) were strong seasonal drivers. Our research demonstrates that despite the harsh and arid climate of this region, the mangroves of Magdalena Bay were nearly as productive as mangroves found in tropical and subtropical climates around the world. As one of the largest mangrove ecosystems in Baja California, our results broaden understanding of the ecosystem services these coastal forests provide, with a potential important role in carbon budget mitigation plans for the Baja California Sur region.