Modeling Regional Paleovegetation of the Holocene in EasternUnited States: Upper Great Lakes

Abstract ATM-9709633 Sugita, Shinya University of Minnesota Title: Modeling Regional Paleovegetation of the Holocene in Eastern United States; Upper Great Lakes Climate and vegetation in the Upper Great Lakes region have been influenced not only by continental-scale movement of air masses but also by substrate and regional physiographical features such as Lakes Superior, Michigan and Huron. Retreat of the continental ice sheet and subsequent isostatic rebound dramatically altered sizes and shapes of the Great Lakes and Lake Agassiz during the late- glacial and early Holocene, which undoubtedly affected the regional climate. Shifts in the location of the prairie-forest border are likely to have had further feedback effects on the regional climate. This award supports an examination of Holocene climate/vegetation interactions in the Upper Great Lake region, and the preparation of regional models of climate (RegCM2) and flora/vegetation models as simulations of the present and of 11 k, 6 k and 3 k calibrated yrs. A pollen dispersal/deposition model, will link regional vegetation predicted by the vegetation models to pollen assemblages in lakes, which can be compared with observed fossil pollen from the regional database. Through this model/data comparison, the effectiveness of simulations which couple regional climate and vegetation models will be evaluated. The density of good-quality, well-dated pollen records in the Upper Great Lakes region is now extremely high, allowing a more spatially detailed model/data comparison than would be possible in most other regions of the globe.