A PALYNOLOGICAL STUDY OF WETLAND DEVELOPMENT IN THE SHARK RIVER ESTUARY, EVERGLADES, FLORIDA, SINCE THE MID-HOLOCENE

In this paper, palynological analyses were performed on cores retrieved from four mangrove-dominant wetland sites along the Shark River Estuary, south Florida. The main objective is to study the development of mangrove ecosystems in the southwest Everglades from the mid-Holocene and millennial-scale processes driving the ecological and hydrological changes. The pollen results indicate that the Shark River Estuary underwent 3 major transformations since the mid-Holocene. Marl prairies were the dominated vegetation type before they were progressively replaced by long-hydroperiod prairies after ∼5700 cal yr BP. long-hydroperiod prairies were then replaced by brackish marsh from 3800 to 2000 cal yr BP. Finally, a significant expansion of mangroves occurred over the last 1000 years. All the wetland transformations started at the mouth of the Shark River Estuary and then progressed upstream. Therefore, we believe that the wetland development in southwestern Florida was primarily driven by the Holocene sea-level rise.