The Big Thicket is the name given to a somewhat imprecise region of a heavily forested area of Southeast Texas in the United States. This area represents a portion of the mixed pine-hardwood forests or "Piney Woods" of the Southeast US. The National Park Service established the Big Thicket National Preserve (BTNP) within the region in 1974 and it is recognized as a biosphere reserve by UNESCO. Although the diversity of animals in the area is high for a temperate zone with over 500 vertebrates, it is the complex mosaic of ecosystems and plant diversity that is particularly remarkable. Biologists have identified at least eight, and up to eleven, ecosystems in the Big Thicket area. More than 160 species of trees and shrubs, 800 herbs and vines, and 340 types of grasses are known to occur in the Big Thicket, and estimates as high as over 1000 flowering plant species and 200 trees and shrubs have been made, plus ferns, carnivorous plants, and more. The Big Thicket has historically been the most dense forest region in Texas.
Existing literature states that Native Americans were known to have lived and hunted in the area nomadically, but did not establish permanent settlements there before the Alabama–Coushatta settled in the northeast about 1780. However, there is insufficient archaeological evidence to support this claim. What records that do exist could suggest human occupation dating back to the Clovis culture 13,400–12,700 years ago, with numerous era diagnostic points being found in all but one of the counties commonly considered to be in the Big Thicket. Spanish explorers and missionaries had a sporadic presence in the region, however colonization and settlement was not their aim, preferring to establish forts outside of the Region where the French were encroaching from the east (namely around Natchitoches, Nacogdoches, and the lower Trinity river valley).
After the 13th Amendment to the U.S. Constitution was officially ratified and adopted in late 1865, “Emancipated people settled in the Big Thicket and survived off the land, using the woods of southeast Texas for homesteading, hunting, and foraging.”
Logging in the late 19th and 20th centuries dramatically reduced the forest concentration. Efforts to save the Big Thicket from the devastation of oil and lumber industries started as early as the 1920s with the founding of the East Texas Big Thicket Association by Richard Elmer Jackson.
Conservatively the area occupies all of Hardin County, most of Polk, and Tyler Counties, and parts of Jasper, Liberty and San Jacinto Counties, including areas between the Neches River on the east, the Trinity River on the west, Pine Island Bayou on the south, to the higher elevations and older Eocene geological formations to the north. Broader interpretations have included the area between the Sabine River on the east and the San Jacinto River on the west including much of Montgomery, Newton, Trinity, and Walker Counties, as well. Several attempts to define the boundaries of the Big Thicket have been made, including a biological survey in 1936 which included over covering 14 counties. A later botanical based study in 1972 included a region of over . This same habitat extends into Louisiana and eastward.
Geography
Physical geography
Geology: The Big Thicket is notable for the unusually high diversity of plants concentrated in a relatively small area. A major factor enabling this diversity is an unusually high diversity of soils. The exposed surface soils are relatively recent, late Cenozoic Era, predominantly Miocene, Pliocene, Pleistocene, and Holocene Epoch formations. Other than some slight and uniform tilting, the strata are not greatly deformed. The strata were laid down in several cycles of glaciations and warmer interglacial interludes. Although glaciers never extended as far south as Texas, it was during these cold periods that enough water was frozen in polar regions to lower sea levels and the Big Thicket area was dry land well above sea level. Conversely, during the warmer interludes, enough ice melted to increase sea levels and submerge Southeast Texas in the sea. It was during those warmer periods of submersion that alluvial and delta deposits from the streams and rivers of the continent laid down the succession of strata, each new layer burying and compacting the previous. At some point there was an approximately 1% tilting of the layers. Some say it was caused by the rising of the Rocky Mountains,Fritz, Edward C. (1993) Realms of Beauty: A Guide to the Wilderness Areas of East Texas, revised edition. University of Texas Press, Austin. 120 pp. while others say it was the weight of the successive deposits that eventually caused the Gulf of Mexico to subside. The older Pliocene, Miocene, and Oligocene formations are exposed in the north (Polk, San Jacinto, and Tyler counties), while the more recent Quaternary Period formations are exposed in the south (Hardin and Liberty counties).Geology of Texas, Bureau of Economic Geology, The University of Texas, Austin (Accessed 7 December 2019)
Soils: The soils of the various formations at the surface have shifted and intermingled through erosion and other factors over time and can be locally quite complex. The Big Thicket contains a greater variety of soils than any area of comparable size in the United States. Sources vary, but from 50 to 100 soil types are said to occur in Hardin County alone. The surface soils tend to be slightly to strongly acidic, and only occasionally neutral in much of the Big Thicket Basin. However, calcareous or alkaline soils do occur in the region, particularly along the Trinity River, in the Beaumont Formation to the south, the Fleming Formation to the north, and northern areas of the Willis Formation where the layer is thin and erosion and road cuts have exposed the Fleming Formation. Most plants are sensitive to soil pH levels (acidic, neutral, or alkaline) and many species will only grow in areas with a specific soil type. Claude A. McLeod's study stated that the Big Thicket was "an edaphicmesophytic climax forest" – edaphic, meaning the soil is a greater influence on the plants than the climate, and mesophytic meaning a medium moisture level.
Topography: The Big Thicket Basin has been described as shallow bowl or dish, tilted to one side, with the high rim on the interior north and low rim on the coastal south. Eastern and western rims consist of the low ridges that divide the Neches River and Sabine River drainage on the east and the Neches River and Trinity River drainage on the west. Elevations range from about in the north to in the south, dropping as low as at confluence of the Neches River and Pine Island Bayou. Northern regions are characterized by low gently rolling hills and well-formed drainage systems of streams and creeks in the landscape. The southern regions are comparatively flat, with poor drainage and support moderately extensive wetlands.Cozine (2004) p. x.
Hydrology: Hardin, Tyler, western Jasper and southeast Polk counties are drained by the Neches River and its tributaries: Village Creek and its smaller tributaries (Beach, Theuvenins, Turkey, Hickory, Kimball, Big Sandy, and Cypress creeks) in the north; Pine Island Bayou and its smaller tributaries (Little Pine Island Bayou and Mayhaw Bayou) in the south. Eastern regions, including eastern Jasper and Newton counties, are drained by several relatively short creeks running into the Sabine River. Western regions including central Liberty, northeastern San Jacinto, northern Walker counties and southwest Polk County (via Kickapoo, Long King, and Menard creeks) are drained by the Trinity River. Areas farther west are drained by the San Jacinto River, with east and west forks. Additional wetlands are extensive, including innumerable nameless swamps, cypress sloughs, oxbow lakes, wetland savannas, and baygall bogs. Floodplains and bottomlands in the south, can retain surface water for days and weeks after rain. The Sabine and Neches rivers flow into Sabine Lake, a natural occurring brackish water estuary, just southeast of the Big Thicket. The other large lakes in the region were constructed in the decades following the Second World War, including B.A. Steinhagen Lake (1947–53) and Sam Rayburn Reservoir (1956–65) on the Neches River drainage, Lake Livingston (1966–69) on the Trinity River, Lake Houston (1953) and Lake Conroe (1970–73) on the San Jacinto River.
Climate: The proximity to the Gulf of Mexico gives the region a climate of mild winters, hot summers, and high humidity most of the year. Average precipitation is a year,Big Thicket National Preserve: The Climate of Big Thicket (accessed 7 December 2019) with northern areas receiving about , and southern areas receiving about . However, tropical storms and hurricanes can increase annual rainfall to over . Humidity stays well above 60% most of the time and exceeds 90% often. Winters are mild, with nighttime lows averaging and daytime highs . Winter cold fronts can drop temperatures to freezing, but freezes rarely last for more than a few days, sometimes only hours, averaging about 20 mostly nonconsecutive days each year. Snow is rare, occurring only once every ten years or so. Summer temperatures are hot, with nighttime lows averaging and daytime highs averaging . Temperatures exceed about 110 days each year and days with temperatures above and even above are not uncommon. The high summer temperatures with high humidity levels can produce very high heat index numbers.US Climate Data: Climate, Kountze, Texas (accessed 7 December 2019)
Human geography Population: In 2010, the United States Census Bureau reported a population of 54,635 for Hardin County, with an average of in a county of . The larger towns (and populations from 2010 census) in Hardin County are Kountze, the county seat (2,123), Lumberton (12,448), Silsbee (6,611), and Sour Lake (1,813). Smaller unincorporated communities in the Hardin County include Batson, Honey Island, Saratoga, Thicket, Village Mills, and Votaw.United States Census Bureau (Accessed December 2019)
Tyler County had a total population of 21,766, with an average population of in . The larger towns in Tyler County are Chester (312), Colmesneil (596), Warren (757), and Woodville, the county seat (2,586) with smaller unincorporated communities including Doucette, Fred, Rockland, and Spurger.
Polk County had a total population of 45,413, with an average of in an area of in 2010 including Livingston (5,335), the county seat and the largest town in the county.
Larger towns and cities in the greater region include Beaumont, Jefferson County, located at the southeast corner of the Big Thicket area with a population of 118,296 and Liberty, Liberty County (8,397), on the southern edge of the Big Thicket area. Houston, Harris County, with a population of 2,320,268 (greater metropolitan area over 7,000,000) is one of the largest metropolitan areas in the US with its central, downtown area located by air southwest of the town of Kountze, Hardin County.
Economy: Timber, oil and gas, and agriculture continue to be significant to the economy of the area. Many people commute to work in oil refineries and related industries in the Beaumont area. Other sources list industries providing significant employment in Hardin County as: educational, health and social services, construction, recreation, accommodation and food services, finance, insurance, real estate, and rental and leasing.City-Data.com: Hardin County, Texas (Accessed 10 December 2019)
Biology
Ecosystems