| Phytolith analysis of two sediment exposures from the Lower Salmon River Canyon, Idaho, was carried out to provide a record of past vegetation. Six phytolith zones were defined, spanning full glacial time to the present.;The results are also compared to those of Davis (2001) in order to test the ‘Oasis effect’ hypothesis. This hypothesis suggests that riverine vegetation was stable from 9,000–2,000 BP which would have made the canyon bottoms a more attractive habitation for human settlement than the less stable plateaus and mountainous areas.;The phytolith record does not fully support the ‘Oasis effect’ because there was a steady shift in vegetation to a more restricted woodland component from 6,000 BP to the present as well as an increasing presence of mesic vegetation that peaked by 3,500 BP. |
