West Gulf Coastal Plain

The  West Gulf Coastal Plain (WGCP) covers more than 8,300 square miles and encompasses all or portions of 18 parishes in southwest and central Louisiana extends into several counties in Southeast Texas. Bisected by the Red River, the area is bordered by the coastal prairie region to the south, the Sabine River to the west, the Mississippi River Alluvial Plain to the east and the shortleaf pine-oak/hickory region to the north. 

Current Condition

Like other pine-dominated regions of Louisiana, the longleaf pine forests of the West Gulf Coastal Plain were subjected to wholesale timbering in the early decades of the 1900s. Some areas of longleaf pine never regenerated, although most had enough seedlings, saplings and cone-producing trees to eventually recover. Until relatively recently, much of the region was open range for livestock. Many ranchers would set the dead grass tops on fire in late winter to provide an early spring "green-up" for cattle. One early report described Beauregard Parish as burning from end to end each year! The fires benefited the herbaceous groundcover and helped maintain the openness needed for longleaf pine re-establishment.

Today, due to many land-use changes, less than 10% of the original longleaf pine forests in the West Gulf Coastal Plain remain. Although longleaf pine produces superior timber, it has not been favored as a timber tree, largely due to difficulties in getting seedlings established, perceived loss of investment due to lack of height growth in the "grass stage," and the need for frequent prescribed burning to perpetuate the forest. Most historical longleaf sites have been converted to loblolly or slash pine plantations.

Upon a first visit to the U. S. Forest Service's Longleaf Vista adjacent to the Kisatchie Hills Wilderness Area, many people hardly believe they are in Louisiana. A vista in Louisiana? With rocks?! In a state known for its flat wetland marshes and bayous, the overstory of longleaf pine forest and unusual mesa-like buttes strewn with large sandstone rocks and boulders proves especially dramatic. 

The sandstone rock is part of the Catahoula Formation, which occurs in a relatively narrow band across the area. In some areas, the rock is exposed at or near the surface, minimizing soil development and plant growth. These areas are referred to as sandstone glades and support several rare species, including the small-flowered flame flower and the rare southern red-backed salamander.

Sandstone, or siltstone, is also exposed in some of the small streams in the region, such as Kisatchie Bayou. These streams are very scenic, with clear water flowing over the rocks in "mini-waterfalls" and ripples. In fact, this area boasts Louisiana's tallest waterfall (17 feet) at Sicily Island, an isolated portion of the uplands found within the Mississippi River floodplain.

Another special habitat type present in the uplands is the hillside seepage bog. These areas occur on slopes in longleaf uplands and range from less than a half acre to several acres in size. They are constantly wet from ground water seepage along hillsides, mostly due to the presence of an impermeable layer near the surface blocking downward water percolation. Often this layer is sandstone, but may also be thick layers of clay or siltstone. The bogs can get very mucky, and they support plants such as carnivorous pitcher plants, sundews and bladderworts, as well as native orchids and other beautiful wildflowers, sedges and grasses.

Biodiversity Significance

The longleaf pine ecosystem throughout the southeast is of conservation concern due to excessive habitat loss and the fact that an abundance of species occur exclusively or predominantly in these habitats. The WGCP is no exception. Long separated from their eastern counterparts by the Mississippi River Alluvial Plain, longleaf pine habitats of west Louisiana and east Texas are significantly different in species composition.

In spite of historic land practices, some of the best remaining longleaf pine habitats in the Southeast are to be found in the Louisiana portion of the West Gulf Coastal Plain. This region supports many rare species of plants and animals. Perhaps the most distinctive rare animal in this ecoregion is the state endemic Louisiana pearlshell mussel, a threatened species found only in a few small sandy streams in central Louisiana. The best known rare animal in the region is the endangered red-cockaded woodpecker, which reaches its greatest abundance in longleaf pine regions throughout the southeast. Additional globally-rare animals associated with longleaf pine, include Bachman's sparrow, Louisiana pine snake, and Kisatchie salamander.

Conservation Efforts

TNC has established three of Louisiana's most significant preserves within this region. Persimmon Gully in Calcasieu Parish supports the only protected example of longleaf pine savanna on high-saline soils, CC Road Savanna in Allen Parish protects the only known population of American chaffseed east of Georgia, and Copenhagen Hills Preserve supports a variety of globally rare plant communities and what may be more species of woody plants that any other area of similar size in North America.

Much of the remaining upland longleaf forests in Louisiana and Texas are now in public ownership. Five of the six districts of the Kisatchie National Forest occur in the WGCP longleaf pine region as do two military training facilities, Fort Polk Army Reservation and the National Guard's Camp Beauregard. Through partnerships with these public agencies, TNC and Louisiana Natural Heritage Program have conducted inventories on these lands and have shared important biological information.

In recent years, the Forest Service has adopted a policy to promote longleaf pine where it occurs naturally on its lands. In addition to maintaining current longleaf pine forests, the agency is restoring areas that were formerly longleaf. Several longleaf areas on the Kisatchie have special conservation status as well, including the Kisatchie Hills Wilderness, the Longleaf Scenic Area, eight registered natural areas and numerous red-cockaded woodpecker sites.

Fort Polk harbors many red-cockaded woodpeckers as well. The Louisiana National Guard has committed to conservation of four longleaf pine demonstration areas at Camp Beauregard, a conservation endeavor made possible by a new program sponsored by the U.S. Fish and Wildlife Service called "Safe Harbor.” Numerous private landowners and timber companies are conserving special sites in this ecoregion as well. 

Exploring the West Gulf Coastal Plain

Hike the Wild Azalea Trail, the Longleaf Vista and many other areas in Kisatchie National Forest or visit the region's state parks, wildlife management areas or the Caroline Dorman Nature Preserve. When you visit this ecoregion, either on foot or by a vehicle, you will no doubt obtain a better understanding and appreciation of this great ecoregion of Louisiana.