Campuses:
By Sara Specht
Under the old oak tree in the back yard a disease may be spreading, offering only some wilted, falling leaves as a sign of infection. When that warning comes, that homeowner has a narrow window to deal with the dying tree, before the sickness spreads through the area.
Caused by an invasive fungus, oak wilt is an aggressive disease that spreads through root systems and through spore production that affects all species of oaks in Minnesota, and is especially lethal to red oak. It can kill trees in a single season, and the primary management tools are root graft barriers, fungicide injections, and the removal of infected trees. The Minnesota Department of Natural Resources offered the Releaf community assistance program to help stem the spread of oak wilt, but because it was decentralized, communities developed very different management strategies with varying degrees of success.
Adam Kokotovich and Adam Zeilinger, graduate students in the Introduced Species and Genotypes IGERT program, went to the source—interviewing local land and forest managers—to find out what was influencing policy enforcement in their districts. They gathered information on 16 oak wilt management programs in the Twin Cities area, illustrating the financial and social challenges facing invasive species management at the local level.
What they found was that both policy and enforcement varied wildly among districts. While about 20 percent of participating communities didn’t have ordinances requiring removal of spore-producing trees at all, almost half of those that did were reluctant to enforce the ordinances because of the financial burden to individual landowners. A few others expanded their oak wilt policy beyond removal to strategically plant other native trees in public lands and to develop relationships for combating future invasive pests. Only about half of the program managers felt the DNR’s goal for oak wilt suppression was obtainable.
“There also was a big difference in the tools people chose to deal with infected trees, depending on whether it was a more rural or urban area,” said Zeilinger, a conservation biology major. “Urban landowners tended to want to save one really old tree in their front yard and were willing to implement fungicide injections even though they aren’t covered by state funds, whereas rural landowners with an acre of oak trees just wanted to stop the spread.”
The research project was part of a semester-long IGERT practicum tackling a real-world invasive species management issue in the spring of 2008. Using in-depth interviews to gather information from an underrepresented source yielded a wealth of data that the team hopes can guide state programs in developing flexible policies for local invasive species management. Their findings were published in the January 2011 issue of the professional journal Urban Forestry and Urban Greening.
“Scientists often focus on the scientific or environmental aspects of policy and management issues,” said Kokotovich, a natural resources science and management major. “Yet equally constituting them are these social and political factors. By looking at them, we can provide important insights for designing improved programs that could otherwise be missed.”
