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’. Given rising concerns over anthropogenic
carbon dioxide (CO2) emissions, mangrove forests have been increasingly
recognized for their potential in climate change mitigation programs.
However, their productivity differs considerably across environments,
making it difficult to estimate carbon sequestration potentials at
regional scales. Additionally, most research has focused in humid and
tropical latitudes, with limited studies in arid and semi-arid regions.
A semi-arid mangrove forest in Magdalena Bay, Baja California Sur,
Mexico was studied to quantify the average net ecosystem exchange (NEE),
determine the annual carbon (C) budget and the environmental controls
driving those fluxes. Measurements were taken during 2012-2013 using the
eddy covariance technique, with a daily mean NEE of -2.25 ±0.4 g C m-2
d-1 and annual carbon uptake of 894 g C m-2 y-1. Daily variations in NEE
were primarily regulated by light, but air temperature and vapor
pressure deficit were strong seasonal drivers. Our research demonstrates
that despite the harsh and arid climate, the mangroves of Magdalena Bay
were nearly as productive as mangroves found in tropical and subtropical
climates. These results broaden understanding of the ecosystem services
of one of the largest mangrove ecosystems in the Baja California
peninsula, and highlight the potential role of arid mangrove ecosystems
for C accounting, management and mitigation plans for the region.