Monitoring of the Invasive Tree, Ailanthus, Takes Flight Over Ohio Forests
Ailanthus altissima (commonly called tree-of-heaven but perhaps more aptly named stink tree), a rapidly growing invasive non-native tree, is spreading into many forested landscapes in the eastern United States and displacing native plants. Because female trees are prolific seeders (350,000 seeds per tree per year) and the prominent seed clusters persist during the winter months, NRS researchers Joanne Rebbeck, Todd Hutchinson, Louis Iverson, and Daniel Yaussy and partners at the Ohio Department of Natural Resources (ODNR), Division of Forestry, were able to develop aerial mapping techniques for finding ailanthus infestations. Using digital sketch mapping technology, they mapped several Ohio state forests by helicopter. The geo-referenced coordinates from these surveys were down-loaded to hand-held GPS units and used by field crews to find and treat ailanthus trees with herbicides. Aerial surveys were expanded to the growing season, and both male and female trees were mapped on more than 45,000 acres in six Ohio state forests. This technique has been very successful, providing forest managers with a cost-effective (25 to 50 cents per acre) and efficient tool to monitor and treat invasive plants across large forested landscapes. Plans are underway to expand aerial ailanthus mapping on the Wayne National Forest.