SERPENTINE GEOECOLOGY BASED ON SOIL SURVEY IN THE RATTLESNAKE GREEK TERRANE, KLAMATH MOUNTAINS, CALIFORNIA

Land managers have recognized that in order to protect endangered species, they need to learn more about their habitats. The distributions of many endangered species in the Klamath Mountains are coincident with the distributions of ultramafic rocks, or more informally, serpentine rocks. While lithology is an important factor, species ditributions are related to landforms, soils, and climate, also. Soils are important links from rocks and landforms to plant communities. Different soils generally have different potentials for plant growth and commonly support different plant communites. Therefore, a good soils map can be adapted to indicate the potential distributions of plant communities.

A soil survey was initiated in the Rattlesnake Creek terrane to delineate landscapes in it, characterize the landforms and soils, and evaluate their potentials for supporting plant communities with endagered species of plants. It was found that slopes are commonly steeper in peridotite than in serpentinite terrain. Also, soils are generally redder on peridotite. Mollisols are most prevalent at low altitudes and Alfisols at higher altitudes up to 1800 meters. At any altitude, Mollisols are more common on serpentinite and Alfisols on peridotite. Plant species distributions are closely related to slope aspect and gradient and to soil properties. A plant survey will ascertain differences in plant distributions, if any, from soils on peridotite to those on serpentinite.