Portland State University. Environmental Science and Resources Ph. D. Program.
Richard R. Petersen
Date of Award
Doctor of Philosophy (Ph.D.) in Environmental Sciences and Resources
Environmental Science and Management
2, xi, 113 leaves : ill.
Paleolimnology -- Oregon -- Bull Run Lake, Paleontology, Freshwater ecology
Detailed analysis of the physical, chemical, pollen and diatom stratigraphy of sediment cores from Bull Run Lake, Oregon reveals that the lake has been subject to repeated episodes of disruption by volcanic ash fall, fire and other disturbance over the past 4300 years. With the exception of fire, these disruptions have not resulted in long term changes in the watershed or in the characteristics of Bull Run Lake. A major fire in the watershed about 750 years ago altered the vegetation. Since that time the forest has been returning to its former condition.
Raymond, Richard Brian, "The paleolimnology of Bull Run Lake: disruption and stability in a natural system" (1983). Dissertations and Theses. Paper 98.