Tidal effects of a salt water river on carbon dioxide and water mixing ratios within a Florida Everglades mangrove forest

A designated research area in the southwestern Everglades National Park, known as the Shark River Riverine Mangrove AmeriFlux Site, houses a flux tower with the necessary computer equipment and power supplies to obtain various atmospheric data sets within a mangrove canopy. Ambient concentrations of carbon dioxide and water vapor are measured at six levels above the forest floor. Water stage and soil temperature, which frequently change with respect to the ebb and flood tides, are measured at the lowest level. Data were collected over the seasons to illustrate the differences in vertical profiles of carbon dioxide and water mixing ratios. Near the forest floor, carbon dioxide profile analysis showed carbon dioxide molar ratios of 430 micro-mols CO2 /(mol air) during May. Ground-level contributors from soil, vegetation, and mangrove roots serve as sources of carbon dioxide into the atmosphere. Such sources can be hampered by flood tides. When tidal-water floods soil and mangrove roots, carbon dioxide concentrations are reduced. Comparing profile systems from different seasons and time of day also show strong variance in carbon dioxide molar ratios within the canopy. Understanding the relationship between the level of tidal inundation and seasons can explain the amount of atmospheric carbon dioxide that the mangrove forest can assimilate.