Vegetation on quartz diorite in the Bear Lakes area, Trinity County, California
Graduation Date
1979
Document Type
Thesis
Program
Other
Program
Thesis (M.A.)--Humboldt State University, 1979
Committee Chair Name
John O. Sawyer
Committee Chair Affiliation
HSU Faculty or Staff
Keywords
Humboldt State University -- Theses -- Biology, Botany--Klamath Mountains (Calif. and Or.)
Abstract
Previous vegetation studies on granitic soils in the Klamath Region of Northern California suggest the area is typically floristically rich and vegetationally complex. My initial reconnaissance suggested the Bear Lakes area is much simpler in both respects. A descriptive and comparative study of this apparently different area was designed. Some 318 vascular plants were inventoried. The vegetation was then sampled following the Braun-Blanquet releve method. There were 198 releves taken. Vegetative and habitat data were analyzed by tabular comparison. Twelve vegetation types resulted; three herb-dominated, three shrub-dominated and six tree-dominated. Detailed comparison of the results with several previous works from nearby granitic areas shows the study area to be relatively floristically depauperate and xerophytic. This is reflected in the simplicity of its vegetation pattern. Dry herbaceous and chaparral types are extensive and are elevationally independent as compared to the less extensive, elevationally zoned forests. Forest zonation at Bear Lakes is similar to other areas in the region. Some forest type descriptions suggest appreciable similarities which become greatest, at higher elevations. The relatively small orographic mass of the study area is principally responsible for differences seen there. It results in steep terrains which support few, extensive, xerophytic communities. More gentle and mesic environments, supporting species-rich vegetation elsewhere, are scarce. The physiography of the study area also results in relatively little snowpack and reduced local climatic gradients. A regional climatic gradient makes the area drier as well. Extensive disturbance by fire promotes simplicity of pattern in the study area. Disturbance in nearby areas, with more complex vegetation patterns, enhances habitat diversity. Differences between Bear Lakes and other areas in the Klamath Region are in both degree and kind. This illustrates the complexity of the Klamath Region vegetation and suggests that regional descriptions need to be flexible.
Recommended Citation
Palmer, John S., "Vegetation on quartz diorite in the Bear Lakes area, Trinity County, California" (1979). Cal Poly Humboldt theses and projects. 1917.
https://digitalcommons.humboldt.edu/etd/1917
https://scholarworks.calstate.edu/concern/theses/x920g009n