Rangeland Ecological Assessment

The Rangeland Ecological Assessment (REA) is a collaborative project between The Nature Conservancy & the Bureau of Land Management. The REA assesses and maps ecological condition and restoration opportunity in New Mexico.

Tools to Assess Grassland Condition

The REA estimates the condition of 14.2 million acres of land in southern New Mexico. It is based on states described in “ecological site descriptions” (ESDs) and expert knowledge. ESDs have been developed by the Natural Resource Conservation Service, and they are a consistent, science and expert-based resource increasingly used by land managers. It focuses on public rangelands - grasslands, shrublands, and savannas - managed by the Bureau of Land Management, and includes some other lands as well. The REA compares current condition to the expected or “reference” condition, and summarizes the vegetation, ecological processes and restorative management options of these states. Depending on these management options the REA interprets restoration potential, or the effort needed to restore states towards or to reference condition.

Goals of the Rangeland Ecological Assessment

The REA has three primary goals. The first is to provide data to policy-makers, land managers and the public that broadly identify rangeland ecological conditions and restoration opportunities. This will help REA users to identify and prioritize candidate landscapes for restoration, target and apply limited resources more effectively to areas and ecosystems in need of restoration, and deliver the greatest return on investment. The second goal of the REA is to provide information in a dynamic, updateable information format. To achieve this goal, a geodatabase has been created that allows managers to create and update maps and analyses over time. The third goal of the REA is to suggest an approach for applying and integrating regional scale data, like the REA, along with other tools as part of a comprehensive restoration strategy.

Key Findings

  • Of the mapped REA lands, 35% is in reference condition and 65% is in non-reference condition.
  • For both grassland and savanna the largest shift from reference condition is associated with woody plant invasion, dominance or alteration. According to ecological site decriptions, such changes may be accompanied by shifts in ecological processes, such as altered fire regimes and erosion.
  • Areas currently in reference condition will require ongoing management attention (such as reintroducing fire) to keep them in this condition.
  • Within the landscapes not currently in reference condition, 21% of mapped REA lands would benefit from a relatively moderate effort to improve their condition.