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Arizona State Office
Release Date: 03/05/13
Contacts: Carrie Templin or Deborah Stevens, (602) 417-9504    
  Elroy Masters, (602) 417-9346    

BLM Issues the Rapid Ecoregional Assessment for the Sonoran Desert

On March 5, 2013, the BLM will release its Rapid Ecoregional Assessment, or REA, summarizing the conditions of the Sonoran Desert ecoregion. The Sonoran Desert REA encompasses land in two states, Arizona and California.  It has an area of 20,552 square miles and includes land administered by 14 BLM field offices.

REAs use existing scientific information to identify resource conditions and trends within an ecoregion which transend 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. 

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.

An additional REA covering the Mojave Basin and Range Ecoregion will be forthcoming later this year.  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.

REAs are a key component of national strategy to address climate change, and are a key component of Arizona’s Strategic Approach. In California, REAs will be a source of information used for the development of the Desert Renewable Energy Conservation Plan or DRECP. REAs integrate interagency and public data, creating a Sonoran Desert-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 scales, 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 the BLM encourages users of the REAs to consider the results of these other assessments as well.

In October 2012, the BLM in Arizona initiated the Madrean Archipelago REA.  This assessment covers lands in Arizona and New Mexico. In addition, the BLM has initiated pre-assessment activities for three REAs:  the Chihuahuan Desert, the Southern Great Plains (3 ecoregions), and the Beaufort Coastal Plain/Brooks Hills ecoregions.  At this time no additional REA are planned for BLM lands in California.

The Sonoran Desert REA will be made available on the internet at For more information on the Sonoran Desert REA, please contact Elroy Masters at (602) 417-9346.

The BLM manages more than 245 million acres of public land, the most of any Federal agency. This land, known as the National System of Public Lands, is primarily located in 12 Western states, including Alaska. The BLM also administers 700 million acres of sub-surface mineral estate throughout the nation. The BLM's mission is to manage and conserve the public lands for the use and enjoyment of present and future generations under our mandate of multiple-use and sustained yield. In Fiscal Year 2014, the BLM generated $5.2 billion in receipts from public lands.

Arizona State Office   One North Central Avenue      Suite 800      Phoenix, AZ 85004-4427  

Last updated: 03-05-2013