Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil during some portion of the year, including the growing season. Hydrology and soil type determine what types of plant and animal communities can live in and on the soil. Wetlands are among the most productive habitats on earth, supporting both aquatic and terrestrial species. They provide important feeding and nursery areas for commercially important species of fish and shellfish, and provide a veritable feast for wading, migrating and wintering birds.
Wetlands have many other practical advantages. They protect shorelines from erosion, filter runoff from the land, and absorb storm surge wave energy, thus protecting life and property. They are often called the "kidneys" of a watershed because they filter out toxins, improving the water quality for surrounding streams, rivers, lakes, estuaries and other wetlands. They provide flood attenuation, water storage, and provide recreation opportunities for people, including nature-watching, birding, hunting, hiking, paddling and fishing. They provide visual or noise barriers that can enhance the appearance and the value of surrounding properties. Wetlands also help natural resource managers better understand climate change impacts, such as sea level rise and natural hazards like hurricanes. The public benefits from the practical and economic value of wetlands, as well as the aesthetic and recreational functions wetlands serve. Although it is difficult to quantify the monetary value of wetlands? functions in terms of cost to an individual taxpayer, it is evident that many of the functions of a destroyed wetland would have to be replaced by the construction of artificial structures at public expense.
Scientists estimate that the lower 48 United States have lost more than half of their wetlands since colonial times. Coastal wetlands, especially, have been seriously threatened. For example, Louisiana alone has 40 percent of the coastal wetlands in the lower 48 States and is still losing from 25 to 35 square miles a year of wetlands to open water because of erosion and subsidence.
Wetlands can be either freshwater or marine (tidal) and Florida has both. Freshwater wetlands can be further categorized as forested or nonforested, the later dominated by hydrophytic trees like cypress, maple, hickory, and gum. Nonforested wetlands would have herbaceous or shrubby plants, with few or no canopy trees. Marine wetlands occur in intertidal or supratidal (above the high tide line) zones, and are populated by salt tolerant woody and herbaceous plants like marsh elder, perennial glasswort, sea purslane, black needlerush, sea lavender, and mangroves.
