Coastal Everglades Wetlands: Hydrology, Vegetation and Sediment Dynamics

This project has three objectives (tasks): 1) operate and maintain the Mangrove Hydrology sampling network; 2) study the dynamics of coastal vegetation (mangroves, marshes) in relation to sea-level, fire, disturbance and restoration; and, 3) measure rates of sediment surface elevation change and soil accretion or loss in coastal mangrove forests and brackish marshes of the Everglades and determine how sediment elevation varies in relation to hydrology (i.e. the restoration).

The objective of this project is to conduct integrated studies to develop an understanding of how hydrologic parameters, disturbance, sediment, and global change (e.g. sea level) influence ecological systems in coastal wetlands. Hydrological factors studied include surface and groundwater stage and conductivity, surface water flow, nutrient concentration and suspended sediment. Fire, freeze, hurricanes and lightning strikes are among the disturbances that are important in coastal wetlands. Sediment elevation changes in coastal wetlands as a function of plant growth and decomposition, accretion or erosion due to tides and surface water flows, fire (in freshwater peats) and hurricanes. Both positive and negative feedbacks on sediment elevation have been discovered. Sea level has increased almost 30cm in the past century. The influence of continued sea level rise on CERP for restoring coastal areas is unknown at present. These questions have been addressed by the development of an integrated network of sampling and measurement sites where instrumentation is collocated. Many sites have surface and ground water sampling wells, sediment elevations tables and permanent vegetation plots. Transects, with both permanent plots and hydrology sampling wells, have been established across the mangrove - marsh ecotone to examine the influence of hydrology and fires (both partly controllable), freezes and sea level (not manageable) on the position of the ecotone.