Palynological Evidence for the Historic Expansion of Juniper and Desert Shrubs in Arizona, U.S.A.
Davis OK and Turner RM. 1986. Palynological Evidence for the Historic Expansion of Juniper and Desert Shrubs in Arizona, U.S.A.. Review of palaeobotany and palynology. 49(3-4):177-193
Analysis of the sediment of Pecks Lake, Yavapai County, Arizona, has permitted the first r( ported palynological evidence for the historic expansion of juniper and desert shrubs in the American Southwe, t. The palynological evidence is supported by the comparison of modern and historical photographs, which shows t[e regional expansion of pinyon juniper woodland, and the local increase of mesquite and creosote bush. A gradue 1 increase in juniper pollen percentages began over 2000 years ago, but the rate of increase abruptly accelerat.~d after the historic introduction of grazing animals. In contrast, juniper percentages did not increase during a prehistoric interval of intense disturbance by humans, about A.D. 1200, and a different weed flora was present. Prehisl orically, water depth was greatest at ca. 600 B.C. and was lowest just prior to the arrival of Europeans. Regional (limate has gradually cooled since the beginning of the record at 2630 B.P.
- Type
- Journal Article
- Authors
- Davis, Owen; Turner, Raymond
- Units
- MOCA , TUZI
- Keywords
- 2, AZplants, Desert, Juniper (Juniperus), NRCA, Palynology, Peck's Lake (AZ), Plants, Shrubs, Vegetation, Want