Pretreatment variation in overstory and understory vegetation [Chapter 2]
| Authors: | Richy J. Harrod, Erich Kyle Dodson, Nicholas Povak, David W. Peterson |
| Year: | 2009 |
| Type: | Research Paper |
| Station: | Rocky Mountain Research Station |
| Source: | In: Agee, James K.; Lehmkuhl, John F., comps. Dry forests of the Northeastern Cascades Fire and Fire Surrogate project site, Mission Creek, Okanogan-Wenatchee National Forest. Res. Pap. PNW-RP-577. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. p. 13-34. |
Abstract
Changes in forest vegetation as a result of fire exclusion, sheep and cattle grazing, and large-tree logging have been well documented for western forests (Agee 1998; Arno et al. 1997; Covington and Moore 1994; Everett et al. 2000; Harrod et al. 1999; Hessburg and Agee 2003; Hessburg et al. 2000, 2005). These changes in forest structure and composition have increased the hazard of large, highseverity wildfires (Agee 1994, Peterson et al. 2005, Scott and Reinhardt 2001, Weatherspoon and Skinner 1996), which lead to degraded water quality and costly losses of wildlife habitat, wood products, and residential buildings (Armstrong and Cumming 2003). In addition, current forests have increased vulnerability to many insects and diseases (Hessburg et al. 2005); have altered understory diversity, composition, and abundance (Covington et al. 1997, Hall 1977, Smith and Arno 1999); and generally have an overall deterioration in forest ecosystem integrity (Everett et al. 1996). A reduction in the current risks of uncharacteristically severe wildfires and insect outbreaks is desirable for local communities and many land managers. Before restoration activities are planned, it is important to understand the current variability in vegetation so that treatment effects can be appropriately interpreted.