Middle Atlantic coastal forests


The Middle Atlantic coastal forests are a temperate coniferous forest mixed with patches of evergreen broadleaved forests along the coast of the southeastern United States.

Setting

The Middle Atlantic coastal forests stretch along the Southern Atlantic coast of the United States from extreme Southern New Jersey south to the Georgia coast. They cover the lower Atlantic coastal plain and are bordered on the west by the Southeastern mixed forests.
The habitats of the ecoregion are constantly modified by natural processes. The bottomlands, coastal plains, and maritime areas are vulnerable to tropical cyclones and floods. The drier areas with porous sandy soils are susceptible to fires and drought. Fire return intervals of 1 to 3 years favor herbaceous plants; longer intervals favor dense shrubs, to broadleaved evergreen trees.

Climate

This ecoregion has a humid subtropical climate with hot summers and mild winters, and with the heaviest precipitation concentrated in the warmest months.

Flora

Two basic types of forests are found in this region; 1) Southern mixed hickory-pine-oak forests that see frequent fire with sandy soils, and 2) isolated patches of evergreen broadleaved forests and "hammocks" close to the Atlantic coastline in the southernmost areas in coastal South Carolina and coastal Georgia.
The mixed pine-oak forests occur on dry or sandy soils or in areas exposed to occasional fires. Longleaf pine, superbly adapted to fire-prone environments, was the principal tree in many of these forests; however, extensive logging and human development have reduced this trees occurrence to less than 5% of its former range. Loblolly pine and shortleaf pine grow in sandy soils and are still dominant in this ecosystem. Loblolly is widely planted on millions of acres of plantation forest's across the southeastern US. On moist soils or where fires are infrequent, hardwoods overtake the pines. These hardwoods include turkey oak, post oak, myrtle oak, Spanish oak, and southern catalpa.
Evergreen broadleaved forests occur close to the coast in localized areas as either evergreen Maritime oak forests or as more localized evergreen hammocks. These forests consist of evergreen broadleaved canopy trees, such as Magnolia grandiflora, Magnolia virginiana, Persea borbonia, Gordonia lasianthus, Sabal, and several evergreen oaks such as Quercus myrtifolia, and the iconic Quercus virginiana or southern Live Oak often covered with Spanish moss. The understory is also often evergreen in these forests, with Myrica cerifera and Osmanthus americanus very common, while several evergreen species of Ericaceae, Ilex, and scrub palms are common on more moist sites. In the open areas near sandy beaches and coastal areas, large endemic populations of Yucca and cactus thrive in the hot sun and sandy soils.
The Middle Atlantic coastal forests contain the most diverse assemblage of freshwater wetland communities in North America. These include freshwater marshes, shrub bogs, white cedar swamps, bayheads, and wet hammocks.
The bottomland hardwood forests for which the ecoregion is famous are dominated by bald cypress and swamp tupelo.
Bald cypress swamps are often dominated by their namesake tree, and are too wet for foot travel. Many uncommon orchids grow among the baldcypress branches.
Swamp tupelo, along with water tupelo, dominate mixed-hardwood swamp forests. These grow aside water-adapted oaks that include water oak, swamp chestnut oak, cherrybark oak, willow oak, and overcup oak. Swamp hickory and water hickory are also found here. Pawpaw grows in the understory.
Atlantic white cedar swamps occur along blackwater rivers.
Pocosins are flat and damp, sandy, or peaty areas far from streams. They have scattered pond pine and a dense growth of mostly evergreen shrubs including gallberry.
Barrier islands along the coast protect extensive estuaries, lagoons, and sounds.
Carolina bays are a unique habitat of the ecoregion.

Fauna

The nine-banded armadillo is a distinctive animal that lives in this ecoregion. The Virginia opossum is abundant.
In the mixed pine-oak forests, the brown-headed nuthatch feeds on pine seeds. The yellow-throated warbler is widely distributed. The northern parula warbler and the eastern bluebird are also found here. The Bachman sparrow and red-cockaded woodpecker, both uncommon, also live in this ecoregion.
The bottomland forests support abundant arthropods, produce mast that sustains migratory birds during the winter, and produce boles, branch cavities, and rotting logs that support various detritivores and hole-nesting species. In the extreme southeast regions the large American alligator can be found along tidal inlets and marsh areas.

Contemporary land use

The main causes of habitat conversion are agriculture, fire suppression, urbanization, coastal development, ditching and draining of wetlands, and damming of rivers.
The western part of the ecoregion has been most altered. There, the upland vegetation has been nearly completely converted.
Long-leaf pine savannas have nearly disappeared.
The least altered habitats in the ecoregion are the coastal marshes and deep peatlands.

Remaining intact habitat