The southwestern frequent-fire forests on federal lands are today largely managed for ecological restoration principles, which are effective treatments that reduce stand-replacing fire risk. Our public lands are mandated to support multiple resources, and creating and sustaining wildlife habitat is a key component of management plans.

Over decades of restoration and fire risk reduction work, ERI has summarized impacts of restored forests and untreated, uncharacteristically dense forests on multiple resources and values. In particular, wildlife resources, which were hugely impacted by the historic logging of the keystone structure of large, old trees, have been an important component to study in full ecosystem restoration treatments.

The spatial pattern of trees and tree groups retained after thinning are key factors in determining wildlife habitat quality. Historically, much of the southwestern ponderosa pine landscapes were naturally heterogeneous at fine scales, with multi-aged and clusters of trees interspersed with open areas and an herbaceous understory. This heterogeneity supported a wide range of wildlife species, although not every species was supported on every acre.

Restoring the natural variability of forest composition and structure on the landscape should, in turn, restore native wildlife populations. It is feasible to reduce fire risk, restore natural fire regimes, and improve habitat quality for a variety of wildlife species if strategic thought is given to the spatial pattern of trees and groups of trees retained following thinning, and the distribution of restored treatments across the bigger landscape.

The ERI has synthesized research about restoration treatments and their effects on wildlife in several working papers. Some research highlights on the importance of key forest structural components needed to achieve wildlife habitat objectives include:

• Groups of trees with interlocking crowns provide essential habitat for wildlife, including various bird and squirrel species.
• Openings in the forest are often productive areas for biodiversity — supporting diverse grasses and wildflowers that provide food and habitat for numerous insect, bird, and mammal species.
• A primary goal in forest restoration projects is to reestablish native grasses and wildflowers through the reintroduction of frequent, low-intensity ground fires. Native grasses and wildflowers are key understory plants for pollinators like butterflies and grazing ungulates like mule deer, pronghorn, and elk.
• Standing dead trees (snags) and downed logs provide important habitat and food for wildlife, particularly for bat and bird species, like the flammulated owl.