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.
Additional Resources
Giant Bacteria Found in Guadeloupe Mangroves Challenge Traditional Concepts (23June2022 Berkley Lab; Volland et al. 2022)
Hidden Mangrove Forest In The Yucatan Peninsula Reveals Ancient Sea Levels (ScienceBlog 5Oct2021)
Remote sensing helps track carbon storage in mangroves (21Jun2022 University of Tokyo; Zheng & Takeuchi 2022)