This image dataset in this tile service is a model of the altitude of the bedrock surface at 100 meter resolution and was derived from the data points feature class. Bedrock altitudes range from a high of 1059 meters (above NAVD88) at Mount Greylock to a low of -512 meters on Nantucket.Map service is also available.See full metadata page.

The widespread influence of land use and natural disturbance on population, community, and landscape dynamics and the long-term legacy of disturbance on modern ecosystems requires that a historical, broad-scale perspective become an integral part of modern ecological studies and conservation assessment and planning. In previous studies, the Harvard Forest Long Term Ecological Research (LTER) program has developed an integrated approach of paleoecological and historical reconstruction, meteorological modeling, air photo interpretation, GIS analyses, and field studies of vegetation and soils, to address fundamental ecological questions concerning the rates, direction, and causes of vegetation change, to evaluate controls over modern species and community distributions and landscape patterns, and to provide critical background for conservation and restoration planning. In the current study, we extend this approach to investigate the link between landscape history and the abundance, distribution, and dynamics of species, communities and landscapes of the Cape Cod to Long Island coastal region, including the islands of Martha's Vineyard, Nantucket, and Block Island. The study region includes many areas of high conservation priority that are linked geographically, historically, and ecologically. This dataset includes a land cover GIS layer created from aerial photographs from 1938. Janice Stone interpreted the photos onto acetates which were then redrawn onto USGS topographic maps using a zoom transfer scope to reduce edge distortion from the photographs. The landcover polygons were then digitized into a GIS. As 1938 is near the midpoint between the peak of 19th century agricultural land clearance and the modern plant communities of the region, this data provides valuable information on changing landscape characteristics and vegetation successional patterns which shape the modern landscape.

August 2025