The postglacial vegetational history in the region of Weedon has been studied by pollen analysis of a peat bog and lake sediments. Initial tundra vegetation has been re-placed by the forest, at about 11 000 B.P. Spruce established first, followed by fir stands (10 600 B.P.) and, last, maple communities (9 000 B.P) on the mesic sites. The yellow birch {Betula alleghaniensis) seems to have experienced a delay in its immigration to the region. This contributed to allow the existence of an original type of initial maple community, in which the usual trees now found with maple were then lacking.