Southeastern Plains
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Ecoregion Data
| 65 - Southeastern Plains | |
| Region | |
|---|---|
| USA North America | |
| Parent Ecoregions | |
| Southeastern USA Plains | |
| Child Ecoregions | |
| Rolling Coastal Plain Chesapeake Rolling Coastal Plain | |
| Geography | |
| test geography value | |
| Hydrography | |
| test geography value | |
Description
Ecoregion 65m is a rolling, hilly, dissected portion of the Inner Coastal Plain that is made up of sedimentary material. Lithology is distinct from the adjacent Northern Outer Piedmont (45f) that is composed of metamorphic rocks. The terrain is hillier than the Chesapeake-Albemarle Silty Lowlands and Tidal Marshes (63b). Elevations typically range from 30 to 250 feet and local relief is 25 to 175 feet (7.6-53 m). Relief, elevation, and channel gradients are generally greater than in the Middle Atlantic Coastal Plain (63); correspondingly, drainage also tends to be better. Stream margins can be swampy and stained water can occur. Parts of the Fall Zone are included in the westernmost portion of the Rolling Coastal Plain (65m); here aquatic habitats vary between the islands, pools, swampy streams, and cascades of the zone.
The Rolling Coastal Plain (65m) is mostly underlain by unconsolidated Tertiary sand, silt, clay, and gravels of the Bacons Castle Formation and the Chesapeake Group (Virginia Division of Mineral Resources, 1993); Holocene-age deposits and metamorphic rocks are typically absent. Ultisols are common and have a thermic temperature regime (Buol, 1974); they are better drained than the Aquults of the Middle Atlantic Coastal Plain (63) and are warmer than the soils of the Chesapeake Rolling Coastal Plain (65n). The soils support a potential natural vegetation of Oak-Hickory-Pine Forest (dominants: hickory, longleaf pine, shortleaf pine, loblolly pine, white oak and post oak) (Kuchler, 1964).
Physical Setting
The Fall Line acts as the western border and separates Ecoregion 65m from the higher and lithologically distinct Northern Outer Piedmont (45f). Its eastern limit is the Suffolk and Harpersville scarps which separate it from the low, flat terraces of Ecoregion 63b. Its southeastern boundary is the Surry Scarp that divides it from the middle-elevation terraces of Ecoregion 63e. Ecoregion 65m’s northern border with the Chesapeake Rolling Coastal Plain (65n) is the Potomac River where forest density and soil temperature regimes change.
Biological Setting
Today, Ecoregion 65m is a mosaic of woodland and farmland (U.S. Soil Conservation Service, various dates). Common crops are corn, soybeans, and, in the south, peanuts (Bureau of the Census, 1995). Hardwoods are now more common than at the time of settlement because of frequent fires and the repeated preferential cutting of pine. Woodlands are more extensive than in the Northern Rolling Inner Coastal Plain (65n) to the north of the Potomac River.
Climate
Temperate, moist, long rainy season, cold wet winters, moderate snow