Web services > United States > 2020-2024

GT analysis units W E new [U.S. Fish and Wildlife Service]

U.S. Environmental Protection Agency, Office of Research & Development (ORD) - National Health and Environmental Effects Research Laboratory (NHEERL) · 2022 Full Details

Georeferenced: false
Attribute Value
Click on map to inspect values

Full Details

Title
GT analysis units W E new [U.S. Fish and Wildlife Service]
Description
Ecoregions by state were extracted from the seamless national shapefile. 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. These general purpose regions 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 within the same geographical areas. The approach used to compile this map is based on the premise that ecological regions can be identified through the analysis of patterns of biotic and abiotic phenomena, including geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology. The relative importance of each characteristic varies from one ecological region to another. A Roman numeral hierarchical scheme has been adopted for different levels for 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 regions whereas the conterminous United States has 84 (U.S. Environmental Protection Agency, 2005). Level IV ecoregions are further subdivisions of Level III ecoregions. Methods used to define the ecoregions are explained in Omernik (1995, 2004), Omernik and others (2000), and Gallant and others (1989). Literature cited: 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, 152p. Omernik, J.M., 1995, Ecoregions - a framework for environmental management, in Davis, W.S. and Simon, T.P., eds., 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 Science, Arts, and Letters, v. 88, p. 77-103. Omernik, J.M., 2004, Perspectives on the nature and definitions of ecological regions: Environmental Management, v. 34, Supplement 1, p. s27-s38. Comments and questions regarding Ecoregions should be addressed to Glenn Griffith, Dynamac Corporation, c/o US EPA., 200 SW 35th Street, Corvallis, OR 97333, (541)-754-4465, email:griffith.glenn@epa.gov Alternate: James Omernik, USGS, c/o US EPA, 200 SW 35th Street, Corvallis, OR 97333, (541)-754-4458, email:omernik.james@epa.gov
Creator
U.S. Environmental Protection Agency, Office of Research & Development (ORD) - National Health and Environmental Effects Research Laboratory (NHEERL)
Temporal Coverage
Last Modified: 2022-07-12
Date Issued
2022-07-12
Rights
no special restrictions
Access Rights
Public
Format
ArcGIS FeatureLayer
Language
English
Date Added
August 10, 2025
Provenance Statement
The metadata for this resource was last retrieved from U.S. Fish and Wildlife Service Open Data on 2025-08-24.

Links

Cite and Reference

  • Citation
    U.S. Environmental Protection Agency, Office of Research & Development (ORD) - National Health and Environmental Effects Research Laboratory (NHEERL) (2022). GT analysis units W E new [U.S. Fish and Wildlife Service]. . https://gis-fws.opendata.arcgis.com/datasets/fws::gt-analysis-units-w-e-new (web service)
  • BTAA Geoportal Link

View more items like this one...

USGS Ecoregion Boundaries 1987 [Indiana]

1987

Omernik's Level III Ecoregions of the Continental United States, 2003

2003

Oregon Ecoregions [Oregon]

2024

Ecoregions NNLP [Nebraska]

2021

Southeast Blueprint 2024 Subregions [U.S. Fish and Wildlife Service]

2024

Midwest Conservation Blueprint Ecoregions [U.S. Fish and Wildlife Service]

2024

Level III Ecoregions [Oregon]

2023

WorkingLandsEEMSmodel CLIP [U.S. Fish and Wildlife Service]

2018

Estuarine Coastal Condition (Southeast Blueprint Indicator) [U.S. Fish and Wildlife Ser...

2025

Atlantic Coast Boundary [U.S. Fish and Wildlife Service]

2025