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Southern Pine Plains and Hills

↑About the Southern Pine Plains and Hills

The Southern Pine Plains and Hills are a region extending from the western end of the Florida panhandle and southwestern Alabama west into Mississippi and far eastern Louisiana. Although most of the region is roughly rectangular in shape, a narrow, discontinuous portion of it also extends farther to the east in Florida. In Mississippi this region is locally referred to as the Pine Hills or Piney Wood.

This region consists of southward-sloping, dissected and irregular plains. There are low, rolling hills, broad, gently-sloping ridgetops, a few steeper side-slopes where cut by streams, and broad, flat bottomlands along low-to-moderate gradient streams with sand and clay bottoms. Streams here tend to be acidic and dark with tannins from decomposing plants. This region is underlain by sediments with variable textures, ranging from clay, through fine sands to coarse sands, and some gravely sands; in the east, there is also some limestone. On the surface, soils are formed in many places on clayey decomposition residuum from these sediments, and along waterways, on more recent alluvial deposits of sand and gravel. Soils here vary in both texture and fertility; in many areas they are droughty and nutrient poor, but there are also some soils higher in nutrients and better at holding water. Hill summits and higher elevations mostly consist of sandy and gravely deposits that are erosion-resistant and form highly-porous, droughty soils. Some areas in the east have karst topography, with underground streams and sinkholes.

The climate is towards the warmer end of a humid subtropical climate. Precipitation and humidity are high year-round; contrasting with some areas in the broader region that have pronounced dry seasons, here there is only a brief, slight decrease in fall, usually peaking in October. Drought stress here is caused primarily by coarse-textured soils. Spring and early summer often brings severe thunderstorms, which can involve large hail and tornados. Winters are mild, with snowfall rare.

This region was originally covered mostly in open forest of longleaf pine (Pinus palustris), with southern mixed forest on the moister, richer sites. On wet sites in the southernmost portion of this region, there was also slash pine (Pinus elliottii). Other important trees included southern red oak (Quercus falcata), turkey oak (Quercus laevis), sand post oak (Quercus margaretta), and saw palmetto (Serenoa repens). Bottomlands supported southern floodplain forests, with cypress-gum swamps on the wettest sites and bottomland hardwoods elsewhere. In the east of this region, especially towards its northern border, there was also some oak-hickory-pine forest.

The forests here have been almost completely cleared, and mostly replaced by monoculture pine plantations, mostly of slash pine and loblolly pine (Pinus taeda). These plantations lack the biodiversity of wild forests, and this conversion has thus resulted in many species dependent on the original forests here becoming endangered or threatened. In addition to the pine plantations, there is a small amount of hay and cattle ranching, and in recent years, increasing amounts of poultry farming. In the east, there is also some cropland on the flatter uplands, and the region produces soybeans, wheat, peanuts, cotton, corn, pecans, sweet potatoes, and tomatoes.

Much of this region is bordered to the north by the Southern Hilly Gulf Coastal Plain, which has on average less droughty soils, a lower portion of pines in wild forests, and presently a greater portion of cropland. There is also a small area towards the middle of this region where it is bordered to the north by the Buhrstone/Lime Hills, a highly rugged area that is still mostly forested and has a greater portion of wild forests. To the south, this region is bordered by the Gulf Coast Flatwoods, a low, flat region with an ocean-moderated climate. Interspersed with this region along the floodplains of major rivers are the Southeastern Floodplains and Low Terraces. In the east, this region is bordered to the east and in places to the north by the Dougherty Plain. The easternmost portion of this region in Florida also has a border to the north with the Tifton Upland. At its western end, this region is bordered to the west by the Southern Rolling Plains.

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↑References

1. Griffith, G.E., Omernik, J.M., Comstock, J.A., Lawrence, S., Martin, G., Goddard, A., Hulcher, V.J., and Foster, T. "Ecoregions of Alabama and Georgia (color poster with map, descriptive text, summary tables, and photographs)", U.S. Geological Survey, Reston, VA (2001) Web.