Determining Heritage Oak Tree Susceptibility to Sudden Oak Death Using GIS Risk Analysis

Abstract

Sudden Oak Death (SOD), caused by the pathogenic water mold Phytophthora ramorum, has killed hundreds of thousands of oak trees in the California coastal regions, with redwood-tanoak forests being hit the hardest (Shoemaker et al., 2007). The term “sudden oak death” is used to describe the disease, because of how rapidly the pathogen has killed otherwise healthy tanoaks, virtually in a matter of weeks (COMTF 2010). SOD was first reported in California in 1994 and is believed to have originated from infected nursery or ornamental plants, but the source has never been identified (Mascheretti et al. 2008).