Trees have made a major comeback in the northeastern United States, but the regrown forest is in some ways markedly different from that of 400 years ago, when European colonists started clearing trees for agriculture.

Jonathan Thompson of the Smithsonian Conservation Biology Institute in Front Royal, Virginia, and his colleagues examined land-survey records from 1620 to 1825 in nine northeastern states. Colonial surveyors often divided up plots of land using 'witness trees' to mark the corners, generally noting the genus, so the authors were able to compare these data with modern forest inventories.

Although most of the same tree species were present in both time periods (with the exception of the now-rare American chestnut, Castanea dentata), their relative abundances differ greatly. Colonists removed a forest dominated by species such as beech and hemlock conifers, but today's trees form a canopy of mostly maple and birch.

PLoS ONE 8, e72540 (2013)