Oak wilt at Belle Isle Park management
In fall 2016, a survey was conducted that revealed that oak wilt may have killed as many as 112 trees in a rare flatwoods forest near the center of the island. The DNR quickly drafted a plan to contain and manage the disease in order to protect the historic forest and some of the state’s last remaining Shumard’s oaks. It was determined that oak wilt may have been present for many years.
To share information about the department’s oak wilt containment and tree protection efforts, the DNR hosted two public informational meetings earlier this year to share information on the DNR's oak wilt containment and tree protection efforts.
Oak wilt at Belle Isle
- Oak wilt was detected in the rare flatwood forest - one of the last remaining Michigan forests of its kind - near the center of the island.
- A survey of Belle Isle’s oaks revealed the disease has been present for many years and may have killed as many as 112 dead trees
- Oak wilt has impacted nearly 48 acres of the island’s 200 acres of forest land.
- It is likely that the oak wilt fungus came to Belle Isle on infected material like firewood. The movement of firewood can introduce sap-feeding beetles that move spores from an infected piece of wood (ie. firewood) to freshly pruned or injured trees.
- The placement of hot coals at the base of trees also affects the health of oaks on Belle Isle.
The DNR is making every effort to preserve as many oaks as possible and is taking swift action to control the spread of oak wilt. The following steps have been implemented and are planned:
Step 1 (late December 2016): In an attempt to halt the spread from tree to tree through underground root connections, crews severed the roots between infected and healthy trees using a plow outfitted with a special cutting blade.
Step 2 (mid March 2017): More than 100 diseased trees will be cut down and removed from the area before fungal mats develop and allow the disease to spread. To prevent damage caused by heavy equipment, a helicopter service will be used to transport felled logs to a staging area in the island for processing. This technique was determined to have the least impact to the surrounding flatwoods forest.
* The Belle Isle Conservancy has contracted with Vertical Flight Technologies for the helicopter service, estimated to take two days. During this time, all access to the forested end of the island, east of Vista Lane, will be closed. The closure will include roads, hiking trails, pathways and facilities and will affect day-use activities. The closure will be marked for visitors.
Step 3 (spring 2017): Approximately 150 oaks in or near areas of known oak wilt, including many of the island’s Shumard’s oaks, will be injected with a fungistat that may prevent infection.
Step 4 (begin late August): The DNR will continue to monitor for infected trees throughout the year. Early detection of future infestations will be critical for successful control.
What can you do?
Since 2009, Michigan state parks have lost more than 500,000 trees to disease and infestation and millions more have been lost statewide. It is likely that the oak wilt fungus came to Belle Isle on infected material like firewood. The DNR reminds travelers and state park visitors to leave wood at home and to instead buy and burn firewood at or near your destination – don’t bring it back home. Please consider the following:
- Do not move firewood. Oak wilt is spread by the movement of infected wood. Hauling firewood, even a short distance, from one part of the state to another is a common way for invasive tree insects and diseases to move to new locations.
- Do not prune oak trees during the growing season. Wait until trees are dormant to prune. Sap-feeding beetles are attracted to wounds caused by pruning and can carry spores from one infected tree to another. If you must prune, seal fresh wounds with paint to prevent contact with beetles.
- Look for and report signs of oak wilt, including sudden leaf drop or leaf color change in summer or patches of dead oaks, to DNR-FRD-Forest-Health@michigan.gov or 517-284-5895.
Funding and Project Management
This project was funded in part with $194,000 from the Michigan Invasive Species Grant Program, through the state departments of Natural Resources, Environmental Quality, and Agriculture and Rural Development.