“…Well-dated pollen and macrofossil studies in the upper Midwest and the Northeast have provided detailed information concerning the patterns of vegetational and climatic change since deglaciation (for example, M.B. Davis 1969, 1981b, Williams 1974, Brubaker 1975 1975, Spear and Miller 1976, Whitehead 1979, Miller and Thompson 1979, Spear 1981, Anderson et al 1986, Overpeck 1985.…”