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(1) Piney Woods. Located in eastern Texas, covering over 15 million acres, this is
gently rolling to hilly forested land. The soils of the region are characterized as deep loamy or sandy soils. Prior to European settlement, this area of Texas supported longleaf pine,
shortleaf pine, loblolly pine, and oak-hickory forests. Today the region is composed of fragmented pine and pine-hardwood forests with some cropland and pastureland. The majority of national
forests and other forestland located in Texas are found in this region, as is Texas's only natural lake, Caddo Lake. Dogwoods and red and white oaks are plentiful throughout the area. Though
rapidly diminishing, the bottomland hardwood forests of oak-hickory, elm, sweetgum, sugarberry, and ash—the most diverse and richest wildlife habitats left in Texas—are located in the piney
woods. The endangered red-cockaded woodpecker's habitat is in the pine forest. Rare plants found in the region include the southern lady's slipper orchid, golden glade cress, white
bladderpod, and Texas trailing phlox. Rare plant communities include longleaf pine savannas and beech-magnolia forest. Swamps, bogs, and man-made lakes extend through the region, which has
the state's highest rainfall, with annual precipitation of 32 to 56 inches. Lumber and cattle production are major industries in the area. Four national forests are located in the piney
woods.
(2) Oak Woods and Prairies. This area is divided into two parts, with one section to
the east of the Blackland Prairie and the other to the west. Portions of the area to the west were called Cross-Timbers by early European settlers because they once had post oak forests
crossing strips of prairie grassland. The region is approximately 19,000 square miles of gently rolling to hilly landscape. The bottomland soils range from sandy loam to clay, while the
prairies have sandy loam or sands. Flora include post oaks, oak-hickory forest, plateau live oak, and tallgrass and mid-grass prairies. Most of the flora and fauna have ranges that extend
northward into the Great Plains or eastward into the forests. This area attracted early European settlers because the open grasslands and surrounding forest areas were ideal for settlement.
Native American tribes also were attracted by this unique combination of prairie and forestland. Today, most of those grasslands have been altered. Large concentrations of migrating geese and
ducks winter in this region and can be observed in places like Hagerman National Wildlife Refuge on Lake Texoma. Cattle ranching is a major agricultural industry in parts of the region. The
endangered Houston toad occurs in the eastern post-oak savanna ecoregion.
(3) Blackland Prairie. The Blackland Prairie region is gently rolling and level land
covering 23,500 square miles. It is named for the rich, deep, fertile black soils that once supported the original tallgrass prairie communities and, due to land-use change, today support
crop production and cattle ranching. Prior to the seventeenth century, this area in East-Central Texas had 12 million acres of tallgrass prairie; now there are less than 5,000 acres. It is
the grassland communities themselves—the big bluestem, little bluestem, switchgrass, and sideoats and associated herbaceous flora that make these prairies unique. Agriculture and development
have threatened the remaining grassland communities with extirpation from Texas. In portions of the region, farmland is threatened with extinction by urban sprawl and development.
(4) Gulf Coast Prairies and Marshes. This nearly level plain area of 13 million acres
borders the Gulf of Mexico from the Sabine River to Corpus Christi Bay. Prior to European settlement and twentieth-century development, this landscape included woodlands of sugarberry, pecan,
elms, and live oaks, and open prairies with native grasses. The soils of the area range from acidic sands to sandy loams, with clays occurring in the river bottoms. The flora include
tallgrasss and mid-grass prairies, cordgrass marshes, mesquite, and acacia. The region includes the barrier islands that protect the coastline from high winds and high ocean waves. The
marshes along the bays and estuaries are important habitat for estuarine and marine species including finfish and shellfish. Rare and near-extinct plants and animals include the slender
rush-pea, Attwater's prairie chicken, and the ocelot.
(5) Coastal Sand Plains. The region occupies approximately 2.5 million acres. The
vegetation of this area can be described as grasslands with coastal oak motts, mesquite granjeno, and salt marshes. It is home to the King Ranch and other large cattle ranches. In the
nineteenth century wild horses roamed the area, and consequently it has been known as the Wild Horse Prairie. The Laguna Madre is adjacent to the coastal counties of this region. It stretches
from Corpus Christi to Port Isabel. The Laguna Madre is the only coastal, hypersaline lagoon system on the North American continent and one of only three in the world. This is an
extremely rich habitat and the breeding ground for most of the shrimp caught in the Gulf of Mexico.
(6) South Texas Brush Country. This area encompasses approximately 18 million acres. It
was once covered with open grasslands and a scattering of trees. The original grasslands have become shrubland due to overgrazing. Today the area is characterized by thorny shrubs (such as
mesquite, acacia, and prickly pear) and patches of palms and subtropical woodlands and riparian corridors. It a biologically diverse habitat and home to many wild and rare species of plants
and animals, including the ocelot and jaguarundi. The aplomado falcon was dependent upon these grasslands, and the loss has caused the falcon's demise. Urban development and agricultural use
threaten the existing wildlife habitat. The natural resources of this region, the Gulf Coast Prairies, and the Coastal Sand Plains region contribute to the local economy of this area, where
bird watching and game hunting have become a source of revenue for the region.
(7) Edwards Plateau. The plateau is approximately 1,500 to 3,000 feet above sea level
and encompasses approximately 19.8 million acres. Rivers, streams, and springs flow through the region. Two major aquifers underlie the area: the Edwards and the Trinity. It is dominated by
limestone terrain but includes a wide variety of soil types, topography, and ecological conditions. Plateau live oak savanna and other oak woodlands and limestone glades occur throughout this
region. It is home to one of the world's most diverse collections of aquifer fauna and endangered and rare species. Some of these plants and animals are found nowhere else on earth. The
golden-cheeked warbler nests only in the Ashe juniper (aka cedar) of the area. The springs and rivers of the region are home to the endangered San Marcos salamander, and the endangered
fountain darter. The rare plants of the region include the basin bellflowers and Texas snowbells. Ranching is the primary agricultural industry, but the natural beauty and opportunities for
wildlife viewing and hunting have created a growing tourist industry in the region as well. The Balcones Escarpment—marked by a sharp topographic relief along the Balcones Fault Zone—borders
the southeastern edge of the region and marks the transition zone between the plateau and the plains country on the south and east. The Balcones Escarpment runs from Del Rio to San Antonio
and then northeast through Austin.
(8) Llano Uplift. This area is known as the central mineral region and is characterized
by large granite domes like Enchanted Rock in Gillespie County. The Llano Uplift is a unique geological formation—a granite mass that runs 70 miles across and is approximately 1,000 feet
above sea level. The area encompasses approximately 3.2 million acres and is surrounded by the Edwards Plateau. The vegetation consists of oak-hickory, oak juniper, mesquite, and grasslands.
Ranching is the dominant agricultural industry, and tourism is emerging as an important economic activity for the region.
(9) Rolling Plains. The rolling plains in North-Central Texas cover approximately 28
million acres. This area, along with the High Plains, is the southern end of the Great Plains of the central United States. Four Texas rivers run through the Rolling Plains: the Canadian, the
Colorado, the Concho, and the Red. The soils are soft prairie sands and clays, and flora include juniper woodlands and prairie mid-grasses. The Cap Rock Escarpment—a cliff that runs
north-south— separates the High Plains and the Rolling Plains. Crop and livestock production are the major agricultural industries of this region.
(10) High Plains. The High Plains region was called the Llano Estacado, or Staked
Plains, by the early Spaniards. (The precise meaning of this designation is not certain.) This region occupies approximately 20 million acres. Like the Rolling Plains, the High Plains is the
southern extension of the Great Plains of the central United States. The High Plains region has also been cited as the outwash sediments from the Rocky Mountains. The region was once home to
herds of buffalo, pronghorn antelope, gray wolves, grizzly bear, and elk. It is now home to the sandhill crane, the kit fox, and the lesser prairie chicken, as well as prairie dogs and
coyotes. The flora include blue gama and buffalo grass. Cottonwoods and willows are found along the rivers and tributaries. Mesquite, sandsage, and Harvard shin oak also occur in this region.
Each fall thousands of wintering waterfowl stop over to rest and feed at the playa lakes (shallow lakes) that dot the region. The Ogallala Aquifer underlies the High Plains and the central
United States. Cotton farming and cattle ranching are the major agricultural industries.
(11) Trans-Pecos. The Trans-Pecos region is the northern portion of the Chihuahua
desert. Regarded as the most complex region of the state, it includes plateaus, desert valleys, and wooded mountains where many rare species are found. The only true mountain ranges in Texas
are in the Trans-Pecos: the Guadalupe, Franklin, Chisos, and Davis ranges. Each mountain range has its own type of plants and animals. The flora of the region include desert scrub, such as
the creosote bush, desert grasslands, pinyon-oak juniper woodlands, yuccas, and agaves. The American peregrine falcon nests in this region. The Rio Grande River creates the region's southern
border, separating Texas from Mexico. Big Bend National Park is in the southern edge of the area in Brewster County, the largest county in Texas.
Source: The descriptions of these ecological regions draws heaviliy on a number of books and resource
materials, particularily materials prepared by the Texas Parks and Wildlife Department
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