Yes, the Everglades is a wetland, and it is one of the largest and most ecologically significant subtropical wetlands in the world. This vast region in South Florida is a unique ecosystem, often described as the “River of Grass” because of its defining characteristic: a slow, shallow sheet of water moving across its entire breadth. The presence of water, special soil types, and uniquely adapted plant life confirms its classification.
Defining the Universal Wetland Criteria
The scientific classification of any area as a wetland relies on the presence of three specific physical and biological characteristics. An area must satisfy all three parameters to be formally delineated as a true wetland ecosystem. These parameters are the universal standards used by environmental scientists and regulatory bodies.
The three criteria are: hydrology, which refers to the presence of water on the surface or within the root zone for a long enough duration during the growing season; hydric soils, which are soils formed under conditions of saturation long enough to develop anaerobic, or low-oxygen, conditions; and hydrophytic vegetation, which is plant life specifically adapted to thrive in these saturated conditions. Hydrophytic plants possess specialized adaptations, such as aerial roots or pressurized gas transport systems, that allow them to survive where other plants would perish.
The Everglades as a Hydrological Marvel
The defining physical trait of the Everglades is its hydrology, characterized by the extremely slow, shallow flow of water known as “sheet flow.” This massive, shallow sheet of water moves almost imperceptibly southward from the Lake Okeechobee region to Florida Bay, covering a vast area. This flow shapes the entire landscape and supports the nickname “River of Grass.”
The duration of this inundation, known as the hydroperiod, directly influences the types of hydric soils that form across the system. In areas with a long hydroperiod (six months or more), low-oxygen conditions lead to the accumulation of organic matter, forming deep peat soils. Conversely, areas with a shorter hydroperiod often develop marl soils, which are mineral-based and composed primarily of calcium carbonate precipitated by submerged microalgae.
This hydrological pattern creates the distinctive ridge and slough landscape, where slightly elevated sawgrass ridges are separated by deeper, interconnected water channels called sloughs. The slight slope across the terrain, sometimes less than 4.5 centimeters per kilometer, enables the water to spread out rather than channel into a traditional river. The movement of this surface water is fundamental to the entire ecosystem’s function and the maintenance of its hydric soil composition.
Unique Ecosystems and Hydrophytic Vegetation
The specific plant communities in the Everglades meet the hydrophytic vegetation criteria for wetland classification. The most widespread plant is sawgrass, a sharp-edged sedge that dominates the vast freshwater marshes. Sawgrass is highly adapted to the saturated peat and marl soils, forming dense stands that tolerate long periods of inundation.
Beyond the sawgrass marsh, the system features a mosaic of other wetland habitats, each hosting specialized hydrophytes. Cypress domes are common, named for the dome-like shape created by taller trees growing in the deepest, wettest center of the depression. In the coastal transition zone where freshwater meets saltwater, extensive mangrove forests thrive, representing the largest continuous mangrove ecosystem in the Western Hemisphere.
These mangroves are salt-tolerant hydrophytes that stabilize the shoreline and provide shelter. Even the slightly elevated, drier areas known as hardwood hammocks are considered part of the overall wetland complex, as their ecology is dependent on the surrounding water levels.
The Role of Wetland Designation
The formal designation of the Everglades as a wetland provides the basis for its ecological protection and restoration. Wetlands perform ecosystem services, including acting as natural water filters by absorbing excess nutrients and pollutants before they can contaminate other water bodies. They also offer natural flood control by slowing and absorbing large volumes of water during heavy rainfall, which is particularly important in South Florida.
The Everglades provides drinking water for millions of Floridians by recharging the underlying aquifer systems. The official wetland status triggers legal protections under federal and state regulations, which govern activities like dredging and filling. This legal framework is the foundation for the Comprehensive Everglades Restoration Plan (CERP), authorized by Congress in 2000.
CERP aims to restore the natural quantity, quality, timing, and distribution of water by re-establishing the historic sheet flow that was disrupted by human development. The multi-billion-dollar effort is designed to revive the ecosystem’s health and ensure its continued function as a natural water management system. Restoring the natural hydroperiod and flow patterns is considered the best defense against long-term threats like habitat loss and the effects of climate change.