Ecoregional Assessments for Western North America

In a series of ecoregional assessments, we have identified lands & waters critical to the conservation of biodiversity across western North America. These assessments can be used to:

  • prioritize conservation activities

  • understand the regional significance of a local site

  • evaluate & avoid activities that may adversely affect conservation values

Reports, maps, and geographic data are now available for 19 desert, mountain, grassland and plateau ecoregions across western North America.

Regional Conservation Planning

Along with partners, The Nature Conservancy has completed a series of ecoregional assessments that identify core habitats within our natural infrastructure across western North America. These places represent the best remaining areas to conserve over 1,000 natural communities and over 3,000 rare, unique and endemic species.

Geographic data to provide conservation solutions

The Nature Conservancy in Arizona has compiled a geographic data set which aggregates the information from 19 ecoregional assessments across western North America. The data set enables exploration of our western landscapes to answer questions such as:

  • Which places are most important to conserve?

  • Who manages our species and habitats?

  • Where are the places that support the most species at risk of extinction?

They can be used with a variety of third-party data sets to evaluate conservation & land management needs and alternative futures that seek to minimize impacts to our natural resources.

Our ecoregional data set for western North America is designed as a personal geodatabase for use with ArcGIS 9.x and Microsoft Access software. It contains geographic features that represent important lands and waters (conservation areas), tables that link these lands to the species and habitats that occur within them (targets), and relationships that allow a user to navigate from conservation areas to targets, and vice-versa.

Broad scientific collaboration

Ecoregional assessments are comprehensive and systematic efforts to identify conservation priorities. The assessments for western North America evaluated over 1 billion acres during an eight-year study period. Collectively, these assessments involved nearly 700 scientists from 125 government agencies, organizations, tribes, universities, and museums.

Many data sets were used to create the ecoregional assessments, including primary data from the scientific literature, new data collected by subject experts, and region-wide data on species and habitats from NatureServe and its network of natural heritage programs and the GAP Analysis Program.


Ecoregional Conservation Assessment Reports (1999-2007)

Original reports summarizing the results of the seven ecoregional conservation assessments completed for the southwestern U.S. and northwestern Mexico by The Nature Conservancy and partners.

Ecoregional Assessment Geodatabase for Western North America (January 2008)

GIS data set that aggregates the information from 19 ecoregional assessments across western North America packaged as a personal geodatabase for use with ArcGIS 9.x and Microsoft Access software products. This dataset may be downloaded from the Arizona Program website

Overview: Ecoregion-Based Conservation Assessments of the SW United States and Northwestern Mexico (July 2006)

Provides an overview of ecoregional assessments and the process used to create a standardized, cross-ecoregional dataset for six ecoregions within and adjacent to Arizona. This report may be downloaded from the Arizona Program website.