ECOREGIONS OF TEXAS 25b 26a 25e 25b 26a 2010 26d BUREAU OF ECONOMIC GEOLOGY 26a 27h SCOTT W. TINKER, DIRECTOR AMARILLO 26c JACKSON SCHOOL OF GEOSCIENCES THE UNIVERSITY OF TEXAS AT AUSTIN 27h University Station, Box X 26b 25i Austin, Texas 78713-8924 (512) 471-1534 25j 27h 35g WICHITA 35g FALLS 35a 26b 29b 35c LUBBOCK 26c 29d 33d TEXARKANA 27i SHERMAN 35a DENTON 33d 35c 25j 33f 0 60 120 mi 32a 35b 25j 26b 0 120 240 km FORT DALLAS 33f 35a 29f WORTH 35b Albers equal area projection 27h 26b 33a 35b ABILENE 32c 29b TYLER 24c 29c 23a 26c 30d 35a MIDLAND 24a 23b EL PASO ODESSA 35b 24a 24b 27j 33f NACOGDOCHES 25k WACO 24d PECOS 25j 29e SAN ANGELO 32c 24c 33b 35e 24a 35b 24d 24d 24e TEMPLE 30d 33f 33C 35e 35b 24d 30b 32a 35f 24d 24d 24e 30a 33c 35f 35b AUSTIN 33b 24b 35f 35b 24d 32b 34a 24b 32c 33e 32c 24c 24a 34a 34a 24d 24b 30c 33f HOUSTON 34g 24c 32b 34a 31b SAN ANTONIO GALVESTON DEL RIO 34a 31a 34c 31d 34c 33b VICTORIA 34a 34h 34a A fuller version of this map exists as a free, downloadable poster from the U.S. Environmen- 34h tal Protection Agency (EPA) at http://www.epa.gov/wed/pages/ecoregions.htm. We thank 31c 34b the many compilers of that information, including Principal Investigator James M. Omernik 34c 34h and his colleagues at the EPA and elsewhere, as cited herein. We also thank Anne Rogers of the Texas Commission on Environmental Quality (TCEQ) for her assistance. Conversion 31d CORPUS CHRISTI from digital to print format was accomplished by Bureau of Economic Geology Media 34b Services staff John T. Ames and Jamie H. Coggin. Text editing was by Lana Dieterich. LAREDO 34i GULF OF MEXICO 34d 23. Arizona/New Mexico Mountains Level III ecoregion 23a. Chihuahuan Desert slopes Level IV ecoregion 31d 23b. Montane woodlands 34e County boundary 34i 24. Chihuahuan Deserts 34f State boundary 24a. Chihuahuan basins and playas BROWNSVILLE 24b. Chihuahuan Desert grasslands 24c. Low mountains and bajadas 24d. Chihuahuan montane woodlands 24e. Stockton Plateau 25. High Plains 25b. Rolling sand plains 30. Edwards Plateau 25e. Canadian/Cimarron High Plains 30a. Edwards Plateau woodland 30b. Llano Uplift 25i. Llano Estacado 34. Western Gulf Coastal Plain 25j. Shinnery Sands 30c. Balcones Canyonlands 30d. Semiarid Edwards Plateau 34a. Northern humid gulf coastal prairies 25k. Arid Llano Estacado 34b. Southern subhumid gulf coastal prairies 26. Southwestern Tablelands 31. Southern Texas Plains 34c. Floodplains and low terraces 26a. Canadian/Cimarron Breaks 31a. Northern Nueces alluvial plains 34d. Coastal sand plain 26b. Flat tablelands and valleys 31b. Semiarid Edwards bajada 34e. Lower Rio Grande valley 26c. Caprock Canyons, Badlands, 31c. Texas–Tamaulipan thornscrub 34f. Lower Rio Grande alluvial floodplain and Breaks 31d. Rio Grande floodplain and terraces 34g. Texas–Louisiana coastal marshes 26d. Semiarid Canadian Breaks 32. Texas Blackland Prairies 34h. Midcoast barrier islands and 27. Central Great Plains 32a. Northern Blackland Prairie coastal marshes 27h. Red prairie 32b. Southern Blackland/Fayette Prairie 34i. Laguna Madre barrier islands and 27i. Broken red plains 32c. Floodplains and low terraces coastal marshes 27j. Limestone plains 33. East Central Texas Plains 35. South Central Plains 29. Cross Timbers 33a. Northern post oak savanna 35a. Tertiary uplands 29b. Eastern cross timbers 33b. Southern post oak savanna 35b. Floodplains and low terraces 29c. Western cross timbers 33c. San Antonio prairie 35c. Pleistocene fluvial terraces 29d. Grand Prairie 33d. Northern prairie outliers 35e. Southern Tertiary uplands 29e. Limestone cut plain 33e. Bastrop Lost Pines 35f. Flatwoods 29f. Carbonate cross timbers 33f. Floodplains and low terraces 35g. Red River bottomlands QAd7842 Ecoregions of Texas Ecoregions denote areas of general Texas, and most continue into ecologically and the conterminous United States similarity in ecosystems and in type, similar parts of adjacent states in the has 84 ecoregions (U.S. Environmental quality, and quantity of environmental U.S. or Mexico. Protection Agency, 2003). Level IV, resources. They are designed to be a depicted here for Texas, is a further This map is based on the premise that spatial framework for research, assess- refinement of level III ecoregions. ecological regions are hierarchical and can ment, management, and monitoring of Explanations of the methods used to be identified through analysis of spatial ecosystems and ecosystem components. define the U.S. Environmental Protection patterns and the composition of biotic and Ecoregions stratify the environment by its Agency’s (EPA) ecoregions are given in abiotic phenomena that affect or reflect probable response to disturbance (Bryce Omernik (1995), Omernik and others differences in ecosystem quality and and others, 1999). These general-purpose (2000), and Gallant and others (1989). integrity (Wiken, 1986; Omernik 1987, regions are critical to the structuring and 1995). These phenomena include geology, implementation of ecosystem management This map is modified from a collab- physiography, vegetation, climate, soils, strategies across Federal agencies, State orative project between EPA Region VI, land use, wildlife, and hydrology. The rela- agencies, and nongovernmental organi- EPA National Health and Environmental tive importance of each characteristic var- zations responsible for different types of Effects Research Laboratory (Corval- ies from one ecological region to another. resources within the same geographical lis, Oregon), the Texas Commission on areas (Omernik and others, 2000). A hierarchical scheme indicates different Environmental Quality (TCEQ), and the levels of ecological regions. Level I U.S. Department of Agriculture—Nat- Ecological and biological diversity of divides North America into 15 ecological ural Resources Conservation Service Texas is enormous. The state encompasses regions. Level II divides the continent (NRCS). Collaboration and consultation barrier islands and coastal lowlands, large into 52 regions (Commission for also occurred with the U.S. Geological river floodplain forests, rolling plains and Environmental Cooperation Working Survey (USGS)—Earth Resources plateaus, forested hills, deserts, and a variety Group, 1997). At level III, the continental Observation Systems Data Center. of aquatic habitats. There are 12 level III United States contains 104 ecoregions, ecoregions and 56 level IV ecoregions in Literature Cited Acknowledgments Bryce, S. A., Omernik, J. M., and Larsen, D. P., 1995, Ecoregions—a spatial framework The BEG acknowledges James M. Omernik, 1999, Ecoregions—a geographic framework to guide for environmental management, in Davis, Principal Investigator, EPA, and Anne Rogers, risk characterization and ecosystem management: W. S., and Simon, T. P., eds., Biological assessment Texas Commission on Environmental Quality (TCEQ), Environmental Practice, v. 1, no. 3, p. 141–155. and criteria—tools for water resource planning and decision making: Boca Raton, Florida, Lewis for assistance and permission to reproduce this map. Commission for Environmental Cooperation Working Publishers, p. 49–62. Group, 1997, Ecological regions of North America— MANAGING EDITOR: Peter Eichhubl toward a common perspective: Montreal, Quebec, Omernik, J. M., Chapman, S. S., Lillie, R. A., and MEDIA MANAGER: Cathy J. Brown Commission for Environmental Cooperation, 71 p. Dumke, R. T., 2000, Ecoregions of Wisconsin: GRAPHICS: John T. Ames and Jamie H. Coggin Transactions of the Wisconsin Academy of Sciences, Gallant, A. L., Whittier, T. R., Larsen, D. P., Omernik, Arts and Letters, v. 88, no. 2000, p. 77–103. J. M., and Hughes, R. M., 1989, Regionalization as A fuller version of this map exists as a a tool for managing environmental resources: U.S. Environmental Protection Agency, 2003, free, color, downloadable poster from the Corvallis, Oregon, U.S. Environmental Protection Level III ecoregions of the continental United States U.S. Environmental Protection Agency (EPA) at Agency, EPA/600/3-89/060, 152 p. (revision of Omernik, 1987): Corvallis, Oregon, http://www.epa.gov/wed/pages/ecoregions/htm. U.S. Environmental Protection Agency— AUTHORS: Glenn E. Griffith (Dynamac Corporation), Omernik, J. M., 1987, Ecoregions of the conterminous National Health and Environmental Effects Sandra A. Bryce (Dynamac Corporation), United States (map supplement): Annals of the Research Laboratory, Map M-1, various scales. Association of American Geographers, v. 77, James M. Omernik (USGS), Jeffrey A. Comstock Wiken, E., 1986, Terrestrial ecozones of Canada: (Indus Corporation), Anne C. Rogers (TCEQ), no. 1, p. 118–125, scale 1:7,500,000. Ottawa, Environment Canada, Ecological Land Bill Harrison (TCEQ), Stephen L. Hatch Classification Series No. 19, 26 p. (Texas A&M University), and David Bezanson (Natural Area Preservation Association). Bureau of Economic Geology The Bureau of Economic Geology, established in 1909, is the oldest research unit at The University of Texas at Austin. The Bureau functions as the state geological survey of Texas, and Director Scott W. Tinker is the State Geologist. The Bureau conducts basic and applied research programs in energy resources and economics, coastal and environmental studies, land resources and use, geologic and mineral mapping, hydrogeology, geochemistry, and subsurface nanotechnology. The University of Texas at Austin • University Station, Box X • Austin, Texas 78713-8924 • 512-471-1534 http://www.beg.utexas.edu • Bookstore: 512-471-7144; order online at http://begstore.beg.utexas.edu/store/.