Masters Thesis

Montane forest vegetation-soil relationships in the Yolla Bolly Mountains, Northern California

The purpose of this study was to analyze montane forest vegetation and soil-physiographic patterns on two geologic units, South Fork Mountain Schist and the Franciscan Assemblage, located on North Yolla Bolly and South Yolla Bolly Mountains respectively. One hundred and ten plots were taken on mesic, north aspects from I524 m to 2438 m in elevation. The composition of the forest vegetation, soil morphological characteristics, and physiographic features were measured at each plot. Agglomerative and divisive clustering models were utilized to aid in the formulation of forest types. Canonical variate analyses were used to investigate the relationships between forest types and soil-physiographic variables. Six distinctive forest types were extracted by the clustering models. Forest patterns were found to be primarily controlled by parent rock, exhibiting unique characteristics on different geological units, and elevation, through the modification of regional climatic factors.