Shrub swamps — also called scrub swamps or buttonbush swamps — are a type of

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

occurring in areas too wet to become

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

s (“true” or

freshwater swamp forest Freshwater swamp forests, or flooded forests, are forests which are inundated with freshwater, either permanently or seasonally. They normally occur along the lower reaches of rivers and around freshwater lakes. Freshwater swamp forests are found ...

), but too dry or too shallow to become

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

es. They are often considered transitional (“mid-successional”) between

wet meadow A wet meadow is a type of wetland with soils that are saturated for part or all of the growing season. Debate exists whether a wet meadow is a type of marsh or a completely separate type of wetland. Wet prairies and wet savannas are hydrologically ...

s or

fen A fen is a type of peat-accumulating wetland fed by mineral-rich ground or surface water. It is one of the main types of wetlands along with marshes, swamps, and bogs. Bogs and fens, both peat-forming ecosystems, are also known as mires. T ...

s and conifer or hardwood swamps. By some classifications, shrub swamps must have at least 50% shrub cover and less than 20% tree cover. Other definitions specify large shrubs with small trees less than in height. Creation of shrub swamps often follows a catastrophic event in a forested swamp (flood, cutting, fire, or windstorm). Another route of development is via drained meadows and fens which progress to shrub swamps as a transitional state to forested swamps.

Development

As a wet meadow matures it begins to fill in with vegetation and as this decomposes the soil thickens creating high spots (

hummock In geology, a hummock is a small knoll or mound above ground.Bates, Robert L. and Julia A. Jackson, ed. (1984). “hummock.” Dictionary of Geological Terms, 3rd Ed. New York: Anchor Books. p. 241. They are typically less than in height and ...

s) above the water. Shrubs and small trees begin to grow on these. Shrub swamp water comes from run-off, streams and rivers and the water moves in and out of the swamp throughout the year. Consequently, they tend to be drier than wet meadows or forested swamps and permit water intolerant plant species to grow on the hummocks. Shrub swamps typically occur on organic soils, such as

muck Muck most often refers to: *Muck (soil), a soil made up primarily of humus from drained swampland Muck may also refer to: Places Europe * Muck, Scotland, an island * Isle of Muck, County Antrim, a small island connected by sand spit to Portmu ...

and shallow

peat soil Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...

s. Common plants found in the shrub swamps of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

include

alder Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few sp ...

willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...

elderberry ''Sambucus'' is a genus of flowering plants in the family Adoxaceae. The various species are commonly called elder or elderberry. The genus was formerly placed in the honeysuckle family, Caprifoliaceae, but was reclassified as Adoxaceae due to ge ...

and

highbush blueberry Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section ''Cyanococcus'' within the genus ''Vaccinium''. ''Vaccinium'' also includes cranberries, bi ...

Types

Palustrine Palustrine wetlands include any inland wetland that contains ocean-derived salts in concentrations of less than 0.5 parts per thousand, and is non-tidal. The word ''palustrine'' comes from the Latin word ''palus'' or marsh. Wetlands within this ca ...

shrub swamp *Circumneutral shrub swamp

Notable shrub swamps

Canaan Valley Canaan Valley () is a large bathtub-shaped upland valley in northeastern Tucker County, West Virginia, USA. Within it are extensive wetlands and the headwaters of the Blackwater River which spills out of the valley at Blackwater Falls. It is a w ...

, West Virginia * Cranberry Glades, West Virginia

References

Pedology Swamps Types of soil Wetlands Shrublands {{ecoregion-stub

Development

Types

Notable shrub swamps

See also

References