| Summary: | Natural and anthropogenic disturbances induce spatio-temporal changes in vegetation, thereby affecting its suitability as wildlife habitat. In particular, disturbances (e.g., fire, grazing, and logging) have resulted in significant changes in the twentieth century vegetation cover in the Eagle Lake Ranger District (ELRD) of the Lassen National Forest in northeastern California. The potential effects of these changes on local wildlife habitat have not been previously quantified. In this study, I quantified these changes in a three-stage process. This involved: 1) generating vegetation maps for 1941 and 2005 at the 16 ha grid resolution, 2) quantifying and analyzing the vegetation change between these two years, and 3) using the vegetation change data for both years to estimate changes in suitable habitat for the Northern Goshawk (Accipter gentiles), the Pine Siskin (Carduelis pinus), the Olive-sided Flycatcher (Contopus cooperi), the California Spotted Owl (Strix occidentalis occidentalis), the American Marten (Martes americana), and the Fisher (Martes pennanti) using the California Wildlife Habitat Relations system. Information regarding these changes will assist land managers in developing appropriate habitat management schemes. Based on the observed vegetation changes and their effect on the suitability of habitat for these species, I propose several management schemes. Because dense stands and remnants of old-growth forests are present in the ELRDs southern and western sections, these areas should be maintained to promote California Spotted Owl, American Marten, and Fisher. Selective logging and maintenance of open conifer and lodgepole pine stands will promote the Olive-sided Flycatcher and Pine Siskin.
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