Vegetation Changes in Sequoia National Park, California

Abstract

Twenty-one vegetation types occurring in Sequoia National Park are described and their changes under western man's influence are documented. Age-population structure of the trees, repeated old photographs, and historical descriptions were the primary evidence for recording and interpreting vegetation changes. These changes are strongly correlated with past land uses. Nineteenth- century livestock grazing is considered to be the primary factor in changes in the blue oak foothill woodland, lodgepole pine and subalpine forests, and various grassland vegetation types. Twentieth-century fire suppression is the primary factor in most changes in the various shrublands and other woodlands and forests. Vegetation changes include increases of introduced species in herb- dominated systems, and increases in cover and density of certain woody plants in tree and shrub-dominated vegetation types.