Site: Florida Coastal Everglades LTER
FCE researchers evaluate mangrove mortality at the mouth of the Shark River estuary after the passage of Hurricane Wilma in October of 2005.
Photo taken by Victor Rivera, May 2009.

Mangrove forests in the Florida Everglades form an ecotone, which is a critical link between freshwater marshes and the marine environments of Florida Bay and the Gulf of Mexico. These forested wetlands provide shoreline protection against storms, “nurseries” for shrimp, fish, and crabs, as well as habitat for several endangered and threatened species such as the American crocodile. FCE researchers have made important contributions to our understanding of mangrove forest structure and productivity trends. FCE researchers installed — and still operate — the first eddy covariance tower in a riverine tall mangrove forest in 2003 to measure the net ecosystem exchange of carbon dioxide between the mangrove forest and the atmosphere. Mangroves remove relatively large amounts (about 1000 g of carbon per m2 per year) of carbon dioxide from the atmosphere compared to other forest types, such as tropical rainforests. Temporal and spatial mangrove forest productivity and structure differences are largely controlled by large-scale disturbances, such as tropical cyclones, which can defoliate and kill mangrove trees. Recovery rates vary with the magnitude of disturbance, but can be accelerated by delivery of nutrients in water and soils from associated storm surge. FCE also has a network of sediment elevation tables (SETs) that measure accretion and relative elevation rates in coastal wetlands. Results from these devices are used in predictive modeling efforts to project magnitudes and consequences of sea-level rise. Further, FCE is collaborating with the Luquillo and the Mexican LTER programs to establish a Caribbean Hurricane Research Network (CHURN) to facilitate cross-site, collaborative research on the ecological and socio-economic factors influencing hurricane impacts on the greater Caribbean coastal regions.

Graph for
Seasonal patterns in net ecosystem carbon exchange (NEE) for the mangrove forest located in the western Everglades. The NEE values were determined from flux tower measurements. The carbon content in leaf litter production is also shown. Despite their harsh habitat, mangroves remove from the atmosphere substantial amounts of carbon, with net assimilation exceeding 1000 grams of carbon per m^2 per year. We now know the environmental and physiological controls on mangrove ecosystems.