Spatiotemporal Gypsy Moth Defoliation Data, Northeastern USA, 1975-2009

This dataset is a spatiotemporal record of gypsy moth defoliation in the Northeastern United States from 1975 to 2009. The data were obtained from USDA Forest Service archives of annual aerial survey maps, which were digitized as sequential raster maps in a geographic information system. The data include the proportion of forest defoliated within 64 × 64 km quadrats and the coordinates of the quadrats. The coordinates (in meters) are derived from the azimuthal equidistant projection. Quadrats where defoliation was detected < 3 years are not included in this dataset. For more methodological detail, see the following publications: Liebhold, A.M., K.W. Gottschalk, E.R. Luzader, D.A. Mason, R. Bush, and D.B. Twardus. 1997. Gypsy moth in the United States: An Atlas. USDAForest Service General Technical Report NE-233; Haynes, K.J., A.M. Liebhold, T.M. Fearer, G. Wang, G.W. Norman, and D.M. Johnson. 2009. Spatial synchrony propagates through a forest food web via consumer-resource interactions. Ecology 90: 2974-2983.