The Texas Blackland Prairies are a temperate grasslandecoregion located in Texas that runs roughly 300 miles (480 km) from the Red River in North Texas to San Antonio in the south. The prairie was named after its rich, dark soil.[3] Less than 1% of the original Blackland prairie vegetation remains, scattered across Texas in parcels.[4]
Setting
The Texas Blackland Prairies ecoregion covers an area of 50,300 km2 (19,400 sq mi), consisting of a main belt of 43,000 km2 (17,000 sq mi) and two islands of tallgrass prairiegrasslands southeast of the main Blackland Prairie belt; both the main belt and the islands extend northeast–southwest.
The larger of the two islands is the Fayette Prairie, encompassing 17,000 km2 (6,600 sq mi), and the smaller is the San Antonio Prairie, with an area of 7,000 km2 (2,700 sq mi). The two islands are separated from the main belt by the oak woodlands of the East Central Texas forests, which surround the islands on all sides but the northeast, where the Fayette Prairie meets the East Texas Piney Woods.
Native Americanhunter-gatherers contributed to the maintenance of the prairie through controlled burns to make more land suitable for hunting bison and other game. Hunter-gatherers continually inhabited the prairie since pre-Clovis times over 15,000 years ago. In historic times, they included the Wichita, Waco, Tonkawa, and Comanche, each of whom were gradually replaced by settled agrarian society. The advent of large-scale irrigated farming and ranching in the area quickly led to widespread habitat loss.
Early Czechoslovakian and German immigrants arrived in the region around 1825 to 1845 and found the rich black soil excellent for farming. By the end of the 19th century 98% of the blackland prairies were cultivated and it was the leading cotton region of the state, also producing sorghum, corn, wheat, and hay. The land was so valuable, crops were planted abruptly up to the roadsides, seldom fenced, and riparian areas were cleared right to the creek banks. Several of the larger cities in the state, such as Austin, Dallas, Fort Worth, San Antonio, Temple, and Waco, are located in the region and the agricultural activity in the area was a significant factor in their growth in the 19th century.[5]: 393–394 p. [6]
The U. S. Bureau of Biological Survey [now the United States Fish and Wildlife Service], led by chief field naturalist Vernon Bailey with a crew of 12 federal field agents conducted a 17-year (1889–1905), statewide survey of the natural history of Texas.[7] The survey collected detailed data on the topography, land use, climate, as well as plant, bird, and mammal specimens, and extensive photographs of the landscape.[5]: 3 p. However, because the natural state of the Blackland Prairie region was so altered, even at that time, that little wildlife remained and the biological survey crew spent little time there, ca. 4% of the total fieldwork.[5]: 311 & 369 p. The human population of Texas in 1900 was less than 3,000,000 (ca. 11 people per square mile), in 2001 it was over 20,000,000 (ca. 78 people per square mile),[5]: 3 p. in 2019 it was nearly 29,000,000 (96 people per square mile).[8] Although 98% of the land was cultivated around 1900, after 1950 a shift in land use occurred, with about 50% in cultivation and a significant increase in pasture for livestock production, ca. 25% tame pasture and 25% rangeland. "As a result of cultivation, overgrazing, and other imprudent land-use practices, there are few if any remnants of climax vegetation in the region."[5]: 394 p.
Ecology
The Blackland Prairie was a disturbance maintained ecosystem prior to the arrival of Europeans. Fires ignited by lightning occasionally swept the area, clearing or reducing the encroachment of trees and shrubs on the prairie, while stimulating the native herbaceous prairie species of forbs and grasses which are pyrophytic, adapted and resistant to wildfires. The exact frequency of fires is unknown but estimated to have occurred at intervals of 5 to 10 years. Herds of bison, and to a lesser extent pronghorn and deer, grazed on the grasses and trampled and fertilized the soil, stimulating the growth of the tallgrass ecosystem. Bison were extirpated from the area by the 1850s.[9][6]
The soil of the Blackland Prairies, from which the "blackland" gets its name, contains black or dark-gray, alkaline clay in both upland and bottomland areas.[4] Some western areas have shallow soils over chalk, while some soils in eastern areas are slightly acidic to neutral, grayish clays and loams over mottled clay subsoils (occasionally referred to as graylands). "Black gumbo" and "black velvet" are local names for this soil. The soils have vertisols properties, shrinking and swelling with moisture content. In dry weather, deep cracks form in the clay, which can cause damage to buildings and infrastructure. Soil management problems also include water erosion, cotton root rot, soil tilth, and brush control.[10]
The rich black 'waxland' soil of these prairies is almost proof against burrowing rodents, which penetrate the region only along some sandy stream bottoms, while the open country tempts jack rabbits, coyotes, and other plains species eastward slightly beyond their usual bounds. Few, if any, species are restricted to these prairie, however, and the effect on distribution is mainly negative." [7]: 19 p.
The negative effect on distribution is evident in the Texas distribution of many wide-ranging species of both eastern and western North American fauna reaching their respective distributional limits in the region of the Texas Blackland Prairies and East Central Texas forests [e.g. eastern: American alligator (Alligator mississippiensis), eastern gray squirrel (Sciurus carolinensis), southern flying squirrel (Glaucomys volans),; western: American badger (Taxidea taxus), western diamondback rattlesnake (Crotalus atrox); and other fauna listed below].
Because of the soil and climate, this ecoregion is ideally suited to crop agriculture. This has led to most of the Blackland Prairie ecosystem being converted to crop production, leaving less than one percent remaining.[4] Some groups estimate that less than 0.1% of the area is remaining.[4] Small remnants are conserved at sites such as The Nature Conservancy's 1,400-acre Clymer Meadow Preserve near Celeste, TX.
The State of Texas administers a number of state parks and wildlife management areas in the region, however they are mostly located around human-made lakes and riparian zones of rivers and creeks, focusing on recreation, fishing, and hunting, and not prairie conservation. Many of these areas are leased, not owned, by the state (* = leased).[21]
^ abcdefSchimidly, David J. (2002) Texas Natural History: A Century of Change. Texas Tech University Press. Lubbock, Texas. xv, 534 pp. ISBN0-89672-469-7
^"Soils of Texas". Texas Almanac. Texas Historical Society. Retrieved 2017-02-26.
^ abSchmidly, D. J. 2004. The Mammals of Texas, 6th. Ed. University of Texas Press, Austin, Texas. xviii, 501 pp. ISBN 0-292-70241-8
^ abReid, Fiona A. 2006. Field Guide to Mammals of North America North of Mexico, 4th ed., Peterson Field Guide Series. Houghton Mifflin Company. New York. xx, 579 pp. ISBN 0-395-93596-2
^ abMulroy, Kevin (Editor-in-Chief). 2002. Field Guide to the Birds of North America, 4th edition. National Geographic, Washington, D. C. 480 pp. ISBN 0-7922-6877-6
^ abPeterson, Roger Troy. 1980. A Field Guide to the Birds: a Completely New Guide to all the Birds of Eastern and Central North America. Houghton Mifflin Co., Boston, 384 pp. ISBN 0-395-26621-1
^ abcDixon, James R. (2013) Amphibians and Reptiles of Texas: with keys, taxonomic synopses, bibliography, and distribution maps. Texas A&M University Press, College Station. 447 pp. ISBN 978-160344-734-8
^ abcPowell, R, R. Conant, and J. T. Collins. 2016. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, 4th ed. Houghton Mifflin Co., Boston, Massachusetts. xiii, 494 pp. ISBN 978-0-544-12997-9
^ abLee, D. S., C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister, and J. R. Stauffer, Jr. 1980. Atlas of North American Freshwater Fishes. North Carolina State Museum of Natural History. x, 867 pp. ISBN 0-917134-03-6
^ abPage, L. M. and B. M. Burr. 2011. Peterson Field Guide to Freshwater Fishes: North America North of Mexico, Second Edition. Peterson Field Guide Series. Houghton Mifflin Company. Boston, Massachusetts. xix, 663 pp. ISBN 978-0-547-24206-4
^ abThomas, Chad, Timothy H. Bonner, & Bobby G. Whiteside. 2007. Freshwater Fishes of Texas: A Field Guide. Texas A&M University Press. College Station, Texas. xiv, 202 pp. ISBN 1-58544-570-3
Ricketts, Taylor H., Eric Dinerstein, David M. Olson, Colby J. Loucks, et al. (1999). Terrestrial Ecoregions of North America: a Conservation Assessment. Island Press, Washington DC.
.jpg)
_(19807535823).jpg)
.jpg)
_2_(4015397483).jpg)
.jpg)
.jpg)
.jpg)
,_Washington_County,_Texas,_USA_(30_March_2012).jpg)
.jpg)
.jpg)
_in_the_Blackland_Prairie_eco-region._Highway_532_east_of_Gonzalez,_Gonzalez_County,_Texas,_USA_(19_April_2014).jpg)
_on_ranchland_in_the_Blackland_Prairie_eco-region._County_Road_269,_Lavaca_County,_Texas,_USA_(19_April_2014).jpg)
