Swamps

Importance of swamps

  • Support many rare plants, invertebrates, and vertebrates.

    • Function as nurseries for shrimp and recreational fisheries

  • Serve vital roles in flood protection

  • Prevent shoreline erosion especially during hurricanes and tidal waves

  • Remove excess nutrients

Freshwater swamps

  • Dominated by woody vegetation adapted to saturated soil conditions

  • Examples include forested swamps, bottomland hardwoods, and shrub swamps (see below)

  • Saturated soils during the growing season, and standing water during other times

  • Highly organic soils that support large, woody vegetation

  • May develop from marshes or in poorly drained depressions.

  • Diverse animal life

Forested swamps

  • Found throughout the United States

  • Often inundated with floodwater from nearby rivers and streams

  • Characteristic vegetation (northeast): red maple, pin oak, highbush blueberry, spicebush, skunk cabbage, marsh marigold, cardinal flower, and orchids.

  • Importance:

  • In very dry years, they may represent the only shallow water for miles

  • Critical to the survival of wetland-dependent species

Bottomland hardwoods

  • Deciduous forests found along rivers and streams of the southeast and south central USA

  • Characteristic vegetation: tupelo, overcup oak, bald cypress, sweetgum, and red maple

Shrub swamps

  • Similar to forested swamps, except shrubby vegetation predominates

  • Soil is often water logged for much of the year

  • Characteristic vegetation: buttonbush, willow, alder, dogwood, and swamp rose

Above: Bottomland hardwoods in the southern USA

Below: Shrub swamp in West Virginia

Saltwater swamps

  • Characterized by salt-loving (halophytic) trees, shrubs, and other plants growing in brackish to saline tidal waters; often found in estuaries

  • Coastal wetlands found in tropical and subtropical regions; cover between 60 - 70% of all tropical coasts

  • In the United States, they are located along the southern tip of Florida and along the Gulf Coast to Texas

  • Sometimes called mangals, because mangrove trees dominate due to their ability to survive in saltwater, as well as freshwater for a limited time (Wang et al. 2011)

    • Red mangroves (Rhizophora mangle), black mangroves (Avicennia germinans), and white mangroves (Laguncularia racemosa) are found in subtropical and tropical areas in both hemispheres, extending to near 28°N to S latitude

    • All are extremely tolerant of saturated conditions; some may be flooded up to their crowns during high tide

    • No other trees can directly grow in saltwater like the mangrove species

  • Constantly replenished with nutrients transported by freshwater runoff from the land

  • Support great diversity of decomposers and filter feeders: large populations of bacteria, worms, protozoa, barnacles, oysters, and other invertebrates.

  • Diverse vertebrate population: fish, wading birds, pelicans, crocodiles, etc.

Above: Red mangroves growing on a coastline

Below: The stilt roots of red mangroves

Additional Resources