The texture of the newly ice free surface will have a great effect on soil formation and as a result will also affect the rate and type of vegetation migration.

If a polished bedrock surface is left by the receding glaciers, it will not readily hold the soil being blown into the area, resulting in poor soil development.

If the area left by the glaciers consists of till, soil is able to accumulate much faster. This type of surface also has a much greater water holding capacity.

As a result, there will be a contrasting vegetation on the two surfaces, with richer vegetation on the till and fewer species on the polished bedrock.

EX. This is seen today with forests of Sugar Maple, Yellow Birch, Eastern Hemlock and Eastern White Pine growing on the till, and only Jack Pine developing on the poor bedrock soil (J.D. Sauer, 1988).