BLM Issues the Rapid Ecoregional Assessment for the Madrean Archipelago



BLM Office:

National Office

Media Contact:

Deborah Stevens
Aaron Wilkerson

The Bureau of Land Management today released its Rapid Ecoregional Assessment, or REA, summarizing the conditions of the Madrean Archipelago ecoregion. The Madrean Archipelago REA has an area of approximately 18.5 million acres and portions of four states in two countries: Arizona and New Mexico in the United States, and Sonora and Chihuahua in Mexico. The U.S. portion of the Madrean Archipelago ecoregion, encompassing 15.7 million acres, is the primary focus of the REA.REAs use existing scientific information to identify resource conditions and trends within an ecoregion which transcend traditional administrative boundaries. This large-scale approach can help land managers and stakeholders assess current resource conditions at an ecoregional scale. The REAs provide science-based information and tools for land managers and stakeholders to consider in subsequent resource planning and decision-making processes, such as Resource Management Plans and Environmental Impact Statements.Additional REAs, covering the Sonoran Desert, Mojave Basin and Colorado Plateau Ecoregions in Arizona, have also been completed. REAs are prepared in cooperation with other federal and state land management agencies, including the U.S. Geological Survey, the Department of the Interior’s lead science agency.The REAs themselves do not contain findings and recommendations, nor do they make management decisions or allocate resource uses. The information, maps, and tools provided by the REAs should inform and strengthen BLM’s analyses of the projected and cumulative effects of various management alternatives to be developed in the future.REAs are a key component of national strategy to address climate change, and are a key component of Arizona’s Strategic Approach. REAs integrate interagency and public data, creating a Madrean Archipelago-wide assessment of ecological conditions, trends, and risks on public lands managed by the BLM. They identify important habitats for fish, wildlife, and other species of concern. For example, REAs identify areas that are less ecologically intact or readily restorable; and where development activities may be directed to minimize potential environmental impacts. REAs then gauge the potential of these habitats to be affected by four overarching environmental change agents: climate change, wildfires, invasive species, and development. In contrast to more traditional BLM assessments, REAs do not assess the conditions of specific areas at a fine scale, such as grazing allotments, nor do they describe desired future conditions.The BLM works at all levels of the agency, and with its many partners who participated in developing these REAs, to ensure that this information is used as the BLM develops management strategies to deal with broad-scale issues. The BLM is aware that other groups, such as the Western Governors’ Association, are working on similar broad-scale assessments and it encourages users of the REAs to consider the results of these other assessments as well.The BLM has initiated pre-assessment activities for three additional REAs: the Chihuahuan Desert, the Southern Great Plains (3 ecoregions), and the Beaufort Coastal Plain/Brooks Hills ecoregions. At this time no additional REAs are planned for BLM lands in Arizona.The Madrean Archipelago REA will be available on the internet at For more information on the Madrean Archipelago REA, please contact Aaron Wilkerson at (602) 417-9683.

The BLM manages more than 245 million acres of public land located primarily in 12 western states, including Alaska, on behalf of the American people. The BLM also administers 700 million acres of sub-surface mineral estate throughout the nation. Our mission is to sustain the health, diversity, and productivity of America’s public lands for the use and enjoyment of present and future generations.