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.
Identifer | oai:union.ndltd.org:pdx.edu/oai:pdxscholar.library.pdx.edu:open_access_etds-1097 |
Date | 01 January 1983 |
Creators | Raymond, Richard Brian |
Publisher | PDXScholar |
Source Sets | Portland State University |
Detected Language | English |
Type | text |
Format | application/pdf |
Source | Dissertations and Theses |
Page generated in 0.0019 seconds