Describing the Spread of Oak Wilt Using a Geographic Information System

The oak wilt fungus (C. fagacearum) spreads both through root grafts to adjacent trees and via insects over longer distances. Effective control of the disease requires a better understanding of the spatial and temporal components of both types of spread. Towards that end, color infrared aerial photography covering a ten-year interval of time was interpreted and then analyzed using a GIS for purposes of describing spread rates and areas affected. The GIS allowed rapid and thorough assessment of both overland and local disease spread. New infection centers were found to occur at greater distances than previously reported, and these new centers accounted in total for the most significant component of increase in total area affected by the fungus.