Evaluating accuracy of two types of early land survey records in the northeastern United States

The accuracy of early land survey records often used ro reconstruct colonia l forest composition was tested for three regions of the northeastern Unite d States: central Massachusetts, the southern part of Berkshire County in e astern Massachusetts and adjacent towns in Connecticut, and northeastern Pe nnsylvania. Simple linear regressions of early proprietor's survey data on average growing degree days revealed significant relationships for oak (Que rcus spp.), beech (Fagus grandifolia), and hemlock (Tusga canadensis) with consistent slopes for all three regions. The patterns fit well with colonia l forest composition as inferred from regional pollen studies and with clim atic preferences of the taxa, suggesting that these proprietor's data provi de an accurate representation of forest composition. The same analyses were done with a subset of five towns where two sets of data were available: pr oprietor's data and road survey data. There were significant differences be tween the two data sets, with the road surveys not related to climatic grad ients. We suggest that different types of survey records represent differen t aspects of forest composition, so that data from specialized surveys such as those for roads should be used only in spatially specific studies where the location of the surveys within a town can be taken into consideration.