Land use: Approximately 65 percent of this area is in farms, and 35 percent is either used for urban development or is urbanizing rapidly. Farms are intensively cropped in Maryland, in Pennsylvania, and in most of New Jersey. They are mostly in pasture or woodland in the northern parts of New Jersey and in Virginia. Forage crops, soybeans, and grain for dairy cattle occupy the largest acreage of cropland. Wooded areas, consisting mostly of farm woodlots, are extensive on the steepest parts of the area. Large centers of population and industry stimulate urbanization throughout the area.
Elevation and topography: Elevation ranges from 25 to 300 m but dominantly is 100 to 300 m. On some ridges and isolated peaks, however, elevation is as much as 500 m or more. The dissected part of the Piedmont Plateau is underlain mainly by granite, gneiss, and schist. Basins are underlain by Triassic traprock, sandstone, shale, and conglomerate. The sedimentary rocks contain numerous dikes and sills of diabase and basalt. Other local areas are underlain by limestone. Topography is mostly gently sloping or sloping. Steeper slopes are mostly on the ridges at higher elevations or on side slopes adjacent to drainageways.
Climate: Average annual precipitation-900 to 1,150 mm. Maximum precipitation is in spring and early in summer. Droughts of 10 to 14 days are common in summer. Average annual temperature-10 to 14 C. Average freeze-free period-160 to 200 days.
Water: Precipitation and perennial streams are the important sources of water. Springs are common in rural areas and provide water for many farmsteads. Water for irrigation comes from streams, ponds, and wells. Shallow wells are important in rural areas, but most of the wells supply a limited quantity of water. Water for urban areas is supplied largely by municipal reservoirs.
Soils: The dominant soils are Udults, Udalfs, and Ochrepts. They have a mesic temperature regime, an udic moisture regime, and mostly mixed mineralogy. They are dominantly well drained, moderately deep or deep soils. Hapludults (Chester, Edneyville, Elioak, Eubanks, and Glenelg series) are dominant on the uplands. Hapludalfs (Duffield, Hagerstown, Montalto, Neshaminy, and Washington series) are less extensive on the uplands. Shaly Hapludalfs (Penn series) and Dystrochrepts (Klinesville series) are common in the Triassic basins on the uplands. Dystrochrepts (Cardiff, Manor, and Mt. Airy series) are common on the steeper slopes. Associated with the dominant soils on the uplands are Hapludalfs (Lehigh, Mount Lucas, and Reaville series) and Fragiudalfs (Lawrence and Readington series). Soils on the flood plains are mainly Dystrochrepts (Bermudian, Codorus, Comus, and Rowland series) and Fluvaquents (Bowmansville and Hatboro series).
Potential natural vegetation: This area supports deciduous hardwood forest vegetation. Chestnut oak, white oak, red oak, hickories, ash, American elm, and yellow-poplar are major species. Yellow-poplar is abundant on the northeast slopes. Tree growth and wood production is considerably less in the Triassic basins than elsewhere in the area. Black walnut and black cherry grow on the well drained sites on flood plains. Eastern redcedar is common on many abandoned cropland areas.
(From "Land Resource Regions and Major Land Resource Areas of the United
States". United States Department of Agriculture Soil Conservation Service
Handbook 296. Dec. 1981. page 107.)