Ecoregions of Kentucky

Introductory text
Literature cited


(NOTE: maps and GIS files may differ. To make sure you are using the most current ecoregion data, download shapefiles of ecoregions)

GIS data (shapefiles, metadata and symbology):
Ecoregions of Kentucky--poster front side

Map (available in PDF format):

Ecoregions of Kentucky--poster back side

Map (available in PDF format):

Level III and IV Ecoregions of Kentucky

Map (available in PDF format):

Level III and IV Ecoregions of Kentucky

Map (available in PDF format):

Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. They are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components. By recognizing the spatial differences in the capacities and potentials of ecosystems, ecoregions stratify the environment by its probable response to disturbance (Bryce and others, 1999). Ecoregions are general purpose regions that are critical for structuring and implementing ecosystem management strategies across federal agencies, state agencies, and nongovernment organizations that are responsible for different types of resources in the same geographical areas (Omernik and others, 2000).

The approach used to compile this map is based on the premise that ecological regions can be identified through the analysis of the spatial patterns and the composition of biotic and abiotic phenomena that affect or reflect differences in ecosystem quality and integrity (Wiken, 1986; Omernik, 1987, 1995). These phenomena include geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology. The relative importance of each phenomenon varies from one ecological region to another regardless of ecoregion hierarchical level. A Roman numeral hierarchical scheme has been adopted for different levels of ecological regions. Level I is the coarsest level, dividing North America into 15 ecological regions. Level II divides the continent into 52 regions (Commission for Environmental Cooperation Working Group, 1997). At level III, the continental United States contains 104 ecoregions and the conterminous United States has 84 ecoregions (U.S. Environmental Protection Agency [USEPA], 2002). Level IV is a further subdivision of level III ecoregions. Explanations of the methods used to define the USEPA’s ecoregions are given in Omernik (1995), Omernik and others (2000), and Gallant and others (1989).

In Kentucky, there are 7 level III ecoregions and 25 level IV ecoregions; all but four level IV ecoregions continue into ecologically similar parts of adjacent states (Griffith, Omernik, and Azevedo, 1998; Woods and others, 1998). Ecological and biological diversity in Kentucky is very strongly related to regional physiographic, geologic, land use, and soil characteristics. Deciduous forests widely covered Kentucky at the time of European settlement. About half is still forested. Extensive "barrens" (i.e. bluestem prairies) were once maintained by fires set by Native Americans on rolling to flat parts of the Interior Plateau (71) and Mississippi Valley Loess Plains (74). Today, these areas are dominated by cropland and pastureland and the historic "barrens" are nearly extinct. Major coal fields occur in the Southwestern Appalachians (68), Central Appalachians (69), Western Allegheny Plateau (70), and Interior River Valleys and Hills (72).

The level III and IV ecoregion map on this poster was compiled at a scale of 1:250,000 and depicts revisions and subdivisions of earlier level III ecoregions that were originally compiled at a smaller scale (USEPA, 2002; Omernik, 1987). This poster is part of a collaborative project primarily between USEPA Region 4, USEPA National Health and Environmental Effects Research Laboratory (Corvallis, Oregon), and the Kentucky Natural Resources and Environmental Protection Cabinet–Department for Environmental Protection (KDEP). Collaboration and consultation also occurred with the U.S. Department of Agriculture–Forest Service (USFS), U.S. Department of Interior–Geological Survey (USGS), The Nature Conservancy, Eastern Kentucky University (EKU), USGS–Earth Resources Observation Systems Data Center, Kentucky Geological Survey, and other Commonwealth of Kentucky agencies.

The project is associated with an interagency effort to develop a common framework of ecological regions (McMahon and others, 2001). Reaching that objective requires recognition of the differences in the conceptual approaches and mapping methodologies applied to develop the most common ecoregion-type frameworks, including those developed by the USFS (Bailey and others, 1994), the USEPA (Omernik 1987, 1995), and the U.S. Department of Agriculture–Soil Conservation Service (1981). As each of these frameworks is further refined, their differences are becoming less discernible. Each collaborative ecoregion project, such as this one in Kentucky, comprises a step toward attaining consensus and consistency in ecoregion frameworks for the entire nation.

Literature Cited:

Bailey, R.G., Avers, P.E., King, T., and McNab, W.H., eds., 1994, Ecoregions and subregions of the United States (map): Washington, D.C., USFS, scale 1:7,500,000.

Bryce, S.A., Omernik, J.M., and Larsen, D.P., 1999, Ecoregions—a geographic framework to guide risk characterization and ecosystem management: Environmental Practice, v. 1, no. 3, p. 141-155.

Commission for Environmental Cooperation Working Group, 1997, Ecological regions of North America—toward a common perspective: Montreal, Commission for Environmental Cooperation, 71 p.

Gallant, A.L., Whittier, T.R., Larsen, D.P., Omernik, J.M., and Hughes, R.M., 1989, Regionalization as a tool for managing environmental resources: Corvallis, Oregon, U.S. Environmental Protection Agency, EPA/600/3-89/060, 152 p.

Griffith, G., Omernik, J., Azevedo, S., 1998, Ecoregions of Tennessee (text, map, summary tables, and photographs): Reston, Virginia, U.S. Geological Survey, map scale 1:940,000.

McMahon, G., Gregonis, S.M., Waltman, S.W., Omernik, J.M., Thorson, T.D., Freeouf, J.A., Rorick, A.H., and Keys, J.E., 2001, Developing a spatial framework of common ecological regions for the conterminous United States: Environmental Management, v. 28, no. 3, p. 293-316.

Omernik, J.M., 1987, Ecoregions of the conterminous United States (map supplement): Annals of the Association of American Geographers, v. 77, p. 118-125, scale 1:7,500,000.

Omernik, J.M., 1995, Ecoregions—a framework for environmental management, in Davis, W.S. and Simon, T.P., editors, Biological assessment and criteria-tools for water resource planning and decision making: Boca Raton, Florida, Lewis Publishers, p. 49-62.

Omernik, J.M., Chapman, S.S., Lillie, R.A., and Dumke, R.T., 2000, Ecoregions of Wisconsin: Transactions of the Wisconsin Academy of Sciences, Arts, and Letters, v. 88, p. 77-103.

U.S. Department of Agriculture–Soil Conservation Service, 198, Land resource regions and major land resource areas of the United States: Agriculture Handbook 296, 156 p.

U.S. Environmental Protection Agency, 2002, Level III ecoregions of the continental United States (revision of Omernik, 1987): Corvallis, Oregon, USEPA–National Health and Environmental Effects Research Laboratory, Map M-1, various scales.

Wiken, E., 1986, Terrestrial ecozones of Canada: Ottawa, Environment Canada, Ecological Land Classification Series no. 19, 26 p.

Woods, A.J., Omernik, J.M., Brockman, C.S., Gerber, T.D., Hosteter, W.D., and Azevedo, S.H., 1998, Ecoregions of Indiana and Ohio: Reston, USGS, map scale 1:500,000.

PRINCIPAL AUTHORS: Alan J. Woods (Dynamac Corporation), James M. Omernik (USEPA), William H. Martin (Division of Natural Areas, Eastern Kentucky University), Greg J. Pond (KDEP, Division of Water, Water Quality Branch), William M. Andrews (Kentucky Geological Survey), Sam M. Call (KDEP, Division of Water, Water Quality Branch), Jeffrey A. Comstock (Indus Corporation), and David D. Taylor (USFS).

COLLABORATORS AND CONTRIBUTORS: Terry Anderson (KDEP, Division of Water, Water Quality Branch), John Brumley (KDEP, Division of Water, Water Quality Branch), Julian Campbell (The Nature Conservancy), Thomas R. Loveland (USGS), Jim Harrison (USEPA), and Mike Mills (KDEP, Division of Water, Water Quality Branch).

REVIEWERS: Mike Barbour (Tetra Tech), William S. Bryant (Professor, Department of Biology, Thomas More College), H.R. DeSelm (Emeritus Professor, Department of Botany, University of Tennessee, Knoxville), and Clara Leuthart (Chair and Associate Professor, Department of Geosciences, University of Louisville).

CITING THIS POSTER: Woods, A.J., Omernik, J.M., Martin, W.H., Pond, G.J., Andrews, W.M., Call, S.M, Comstock, J.A., and Taylor, D.D., 2002, Ecoregions of Kentucky (color poster with map, descriptive text, summary tables, and photographs): Reston, VA., U.S. Geological Survey (map scale 1:1,000,000).

This project was partially supported by funds from the USEPA's Office of Research and Development through USEPA Region IV's Regional Ecological Assessment Program (REAP) via contract 68-D-01-0005 to Dynamac Corporation.

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