Defoliation Data

The data are the annual proportion of land area defoliated by gypsy moths across the Northeastern United States for 1990-2015. Defoliation was mapped with aerial surveys conducted by each state. Frequency of defoliation (0/1) in 1 × 1 km rasters was aggregated into 8 × 8 km grid cells. The data are limited to 1,327 focal grid cells in which defoliation was detected in 4 or more years both in the focal grid cell and at least 1 of the 8 nearest neighbour grid cells. The column headings “xcoord” and “ycoord” are coordinates expressed in meters based on the NAD 1983 Albers Projection, Central Meridian > -96, Standard Parallel 1 = 20, Standard Parallel 2 = 60, Latitude Of Origin = 40 and Datum = D North American 1983. The remaining columns are years 1990-2015