Shrubs, grasses, sedges, and forbs form the understory of ponderosa pine and pinyon-juniper ecosystems. They cover the natural openings in these two ecosystems - openings that were much more extensive historically than they are today. While restoration treatments in these ecosystems typically focus on trees, it is also important to restore the natural diversity and productivity of the understory plant community because a healthy understory provides wildlife habitat and fuel for low-intensity fires that maintain forest structure. Restoring a healthy understory may require little or a great deal of effort, depending upon the site conditions and site history. Many sites still support some native understory species, either living or in the seedbank, in which case thinning of overstory trees and conducting some prescribed fires is often enough to promote the growth of a healthy understory. In situations where the treated area is adjacent to a weed-free area with a highly diverse understory, it may be possible to simply let nature reseed the treated site. Still other sites lack native understory species and their seeds, in which case it may be necessary to reintroduce those species as either seeds or seedlings. In this working paper, we cover this last situation - one where active seeding is needed.

This book has been published a decade after Fires Effects on Ecosystems by DeBano, Neary, and Folliott (1998), and builds on their foundation to update knowledge on natural post-fire processes and describe the use and effectiveness of various restoration strategies that may be applied when human intervention is warranted. The chapters in this book,

Humans have influenced the landscapes and forests throughout the temperate and boreal zones for millennia. Restoration of Boreal and Temperate Forests, Second Edition focuses on the negative impact of human activity, and explains the importance of forest restoration as a way to repair habitat, restore forest structure and function, and counteract t

Cheatgrass (Bromus tectorum) is widespread throughout western North America and is a significant concern for land managers conducting restoration treatments in southwestern ponderosa pine and pinyon-juniper forests. It is common on a few restoration treatment areas in northern Arizona, on severely burned mature/old growth pinyon-juniper sites at Mesa Verde National Park in southwestern Colorado (Floyd et al. 2006), throughout wildfire areas in Zion National Park in southern Utah (U.S. National Park Service 2007), and on areas consumed by wildfire in northern Arizona (Sieg et al. 2003). There is concern that cheatgrass populations may expand further with an increase in the scale and frequency of restoration treatments in southwestern ponderosa pine and pinyon-juniper ecosystems.

Until recently, forest managers have largely ignored the value of maintaining dynamic spatial patterns in forested ecosystems. In the America Southwest, where the norm in overstocked forests that are extremely susceptible to catastrophic fires and/or insect infestations and disease, restoring a spatial pattern of openings and tree groups would help alleviate these threats and move the forests within their historic range of variability. This ERI working paper focuses on restoring a dynamic spatial pattern to ponderosa pine forests in the American Southwest. It also addresses basic questions that land managers and others have about how to restore active spatial patterns across the forested Southwest.