Site-Factor Determinants of the Presettlement Prairie-Forest Border Areas of North-Central Ohio

Abstract

The Sandusky Plains in Marion, Wyandot, and Crawford Counties, Ohio, were one of the easternmost extensions of the Prairie Peninsula. During the presettlement period, they constituted an enclave or an island of prairies, open woodlands of bur oak and hickory, and closed forests of oak set in the beech-maple forests of the till plains of western Ohio. Prairies were associated with broad, flat depressions on the uplands underlain by fine-textured lacustrine deposits. Because of the low permeability of the soil and the seasonal distribution of precipitation, they were alternately very wet in the spring and very dry in the fall. Fires, originating in the flammable matrix of the grasslands, altered the composition of the surrounding woodlands. On marginal sites, fires favored the development of savannas, whereas on the better-drained sites they may have converted closed forests of beech and maple to closed forests of oak.