Partnering to map populations of an Invasive Tree at a landscape level

By Cheryl Coon on Sep 9, 2011

A partnership to map Ailanthus at a Regional scale was started during the winter of 2010. Use of aerial mapping cuts costs and allows for the capture of large amounts of data.

In the fall of 2010, the Wayne National Forest and the Ohio Division of Forestry signed a multi-year Challenge Cost Share agreement. The objective of this agreement was to use ODNR helicopter equipment to aerially map the invasive tree, Ailanthus, in southern Ohio. Since invasive species do not recognize property boundaries, the partners agreed to map all properties, starting with areas within the proclamation boundaries of the Wayne National Forest.

Techniques for mapping were based on previous work that the ODOF had done with the USFS Northern Research Station on the Vinton Experimental Forest. Because of the phenology of Ailanthus and its seed persistence into winter months when there is no interfering leaf cover, the ideal time to conduct aerial surveys for Ailanthus is early to middle winter. The Ohio Division of Wildlife furnished a pilot and helicopter for this project. Two Division of Forestry employees served as spotters on each survey day; one was positioned in the co-pilot's seat, the other in the rear seat on the opposite side of the aircraft. The spotter in the co-pilot's seat also served as the sketch map operator. Infested areas and points were mapped on a Hammerhead tablet PC. A Bluetooth enabled GPS receiver was linked to the software to determine accurate position of the aircraft and of mapped areas and points. The surveys were conducted at an altitude of 150 - 600 feet above ground level at speeds of 55 - 80 miles per hour, depending on vegetation (forest density and structure)and environmental conditions. Survey lines were spaced 1,800 to 2,500 feet apart on a general N-S orientation. Spacing of survey lines was determined depending on distance of visibility based upon vegetation and environmental conditions. When groups of Ailanthus trees were spotted, the pilot would generally circle back around the infested areas to gain a better look and facilitate mapping the area.

Over a period of eight days, the helicopter flew over 163,256 acres, mapping 1,429 populations of Ailanthus which infest over 6,400 acres. Since mapping only maps the reproductive females trees of the Ailanthus populations, there are more acres of infestation beyond these mapped areas. The partners involved with this project applied for and received two grants to continue work on this project. A grant from the USFS, State and Private, for Forest Health Protection will fund two more years of aerial mapping of Ailanthus on Wayne National Forest and surrounding lands in Appalachia Ohio. Additionally, a grant from North Central Integrated Pest Management is funding: local education outreach efforts about Ailanthus, ground truthing of aerial mapping results, surveys for the potential biological control of Ailanthus - Verticillium albo-atrum, and the treatment of Ailanthus stands free of verticillium wilt.

The combined efforts of partners to map, survey, treat and educate about Ailanthus is an effort to have a regional impact on this invasive species and protect native ecosystems of Appalachia Ohio.