Mapping hardwood mortality for the early detection of P. ramorum: an assessment of aerial surveys and object-oriented image analysis

Abstract

Effective monitoring and identification of areas of hardwood mortality is a critical component in the management of sudden oak death (SOD). From 2001 to 2005, aerial surveys covering 13.5 million acres in California were conducted to map and monitor hardwood mortality for the early detection of Phytophthora ramorum, the pathogen responsible for SOD. To assess the spatial accuracy of the aerial detection survey (ADS) program data, we used a mortality stem map generated from aerial photo interpretation (Meentemeyer and others 2007) within the Big Sur ecoregion of California. Although results suggest that the aerial surveys may be under-representing the extent of hardwood mortality in the study area, the ADS program has been successful in detecting infestations of P. ramorum in California. An additional analysis explored the use of object-oriented classification for mapping hardwood mortality. Results of this analysis indicate that object-oriented image analysis has the potential for mapping hardwood mortality and can complement the ADS program.

Parent Publication

• Proceedings of the sudden oak death third science symposium

Citation

Haunreiter, Erik; Liu, Zhanfeng; Mai, Jeff; Heath, Zachary; Fischer, Lisa. 2008. Mapping hardwood mortality for the early detection of P. ramorum: an assessment of aerial surveys and object-oriented image analysis. In: Frankel, Susan J.; Kliejunas, John T.; Palmieri, Katharine M., tech. coords. 2008. Proceedings of the sudden oak death third science symposium. Gen. Tech. Rep. PSW-GTR-214. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. pp. 367-369