An assessment of forest ecosystem health in the Southwest

Abstract

This report documents an ecological assessment of forest ecosystem health in the Southwest. The assessment focuses at the regional level and mostly pertains to lands administered by the National Forest System. Information is presented for use by forest and district resource managers as well as collaborative partners in the stewardship of Southwestern forests. The report establishes a scientific basis for conducting forest health projects, provides a context for planning ecosystem restoration, and contributes to the understanding of the physical, biological, and human dimensions of these ecosystems. Chapters describe Southwestern forest ecosystems of the past, changes since the Colonial Period, and the implications of those changes for the health of current and future forests. Opportunities, tools, and research needs for improving long-term sustainability of these forest ecosystems are also identified.

How resilient are southwestern ponderosa pine forests after crown fires?

“…Stand-destroying fires, historically rare in these forests, are now increasing in size (e.g., Swetnam 1990;Covington et al 1997). Prior to the 1960s, a 20-ha crown fire was considered large (Friederici 2003), whereas in recent years single crown-fire events have burned thousands of hectares (Dahm and Geils 1997;Swetnam and Betancourt 1998).…”

Herbivory of sympatric elk and cattle on Lincoln National Forest, south-central New Mexico

“…Lack of browse (and forest encroachment of meadows) is a result of altered historical disturbance (especially fire) regimes and decreased timber harvest, which has increased stand densities and decreased the quantity of open habitats on LNF (Kaufmann et al 1998;Frost et al 2007). Increasing quantity (by overstory thinning or removal [McConnell and Smith 1970;Wallmo et al 1972;Woods et al 1982;Dahms and Geils 1997;Halbritter and Bender 2011a]) and quality (by prescribed burning in conjunction with harvesting [Covington et al 1997;Dahms and Geils 1997;Halbritter and Bender 2011a]) of palatable browse could potentially alter elk distribution in LNF and lower use of other habitat types such as mountain meadows (Halbritter and Bender 2011a, b). The effect of overstory removal with or without burning was illustrated in the comparatively high relative habitat use of thinned and burned stands by all large herbivores (Table 1).…”

The economics of alternative fuel reduction treatments in western United States dry forests: Financial and policy implications from the National Fire and Fire Surrogate Study

“…Causes of these changes include fire suppression, past livestock grazing and timber harvests, and changes in climate (Parsons and DeBenedetti, 1979;Skinner and Chang, 1996;Weatherspoon and Skinner, 1996;Arno et al, 1997;Westerling et al, 2006). These changes in forest ecosystem integrity increase the probability of large, highseverity wildfires that damage difficult-to-obtain older forest structures such as large old trees (Weatherspoon and Skinner, 1996;Dahms and Geils, 1997;Stephens, 1998). Reports from the Blue Mountains of Oregon and Washington (Everett, 1993), the Columbia River Basin (Quigley and Cole, 1997), and the Sierra Nevada Ecosystem Project (SNEP, 1996;Weatherspoon and Skinner, 1996) have highlighted these problems and have explained the need for large-scale and strategically-located thinning (especially of small trees) and/or other fuel treatments, and the use of prescribed fire.…”