The study proceeded as follows: The distribution of Q. garryana was mapped through field reconnaissance. Annual rings from fifteen trees were counted in order to establish age versus trunk diameter ratios. This greatly simplified the dating of trees. Transects were then run through individual groves to determine population age structures. These age structures, along with Q. garryana's distribution patterns, were graphically compared with historic temperature, precipitation, and growing season data. The effect of livestock grazing on oak reproduction was examined. Potential vagility of the species was evaluated by estimating the potential for acorn dispersion by airfall, streams, vertebrates, and the human (aboriginal) population. Finally, pollen evidence was scrutinized in conjunction with acorn dispersal rates in order to determine the longer term history of Q. garryana in this portion cf its range.
| Identifer | oai:union.ndltd.org:pdx.edu/oai:pdxscholar.library.pdx.edu:open_access_etds-4554 |
| Date | 01 January 1981 |
| Creators | Voeks, Robert Allen |
| Publisher | PDXScholar |
| Source Sets | Portland State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Dissertations and Theses |
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