Managing Town Forests for Emerald Ash Borer

Although your town may not have a confirmed infestation of EAB yet, now is the time to plan how you will manage your town forest in the context of EAB. The closer your town forest is to an infested or high-risk area, the more urgent it is to develop an EAB management plan. Planning in advance of EAB infestation will afford greater flexibility in response once EAB is confirmed in your town or town forest.

Check the Vermont Department of Forest, Parks & Recreation map of current confirmed EAB infestations. Please note that this map only indicates sites where EAB infestations have been previously confirmed; the insect may be more widespread than is indicated on this map.

The following list of considerations is a framework for preparing for EAB in town forests. The process and questions are designed to be flexible and can be adapted to meet your community’s needs and capacity. Your town may not need to address every consideration or may choose to go through them in a different order.

1. Organize a Team

Create a team that will guide the planning for EAB in your town forest. Identify the people in your community who can help develop and implement your EAB management plan. Potential members might include conservation commission members, select board members, the town Tree Warden, parks staff, recreation groups, teachers, and other potential volunteers and stakeholders. Your county forester will also be an invaluable resource. If your town forest has a conservation easement, the land trust or easement holder should also be engaged. If your easement is through the Vermont Land Trust (VLT), their regional staff foresters are also a resource for you. Additional information on the management of town forests is available in the Vermont Town Forest Stewardship Guide: A Community Users’ Manual for Town Forests and the Town Forest Recreation Planning Toolkit.

2. Inform and Involve the Community in Planning

Keep your community informed as much as possible. Increasing participation in setting goals and contributing to management decisions about EAB and the town forest will ensure that the community will help steward and care for this shared resource in the future. Below are a few ways to keep residents informed and engaged in the process of developing a management plan for EAB and other invasive pests.

  • Post information about the planning process and a draft of the plan to the town website.
  • Place flyers about EAB, the planning process, and upcoming meetings in the town clerks’ office.
  • Write articles in the local newspaper or newsletter.
  • Post information to Front Porch Forum and or the town forest Facebook page.
  • Flag ash trees identified for removal or preservation with explanatory signage.
  • Post signage on forest trailheads about EAB and proposed plans.
  • Invite your county forester to conduct ash and forest management walks in the town forest or as a webinar.
3. Assess Existing Plans and Policies

Town Forest Management Plan

Some towns in Vermont already have forest management plans for their town forests. If your town does not, now is the perfect time to create one. If your town forest has a management plan but it does not include EAB, the plan should be updated to include EAB response and management. Again, your county forester or a consulting forester can help conduct an initial town forest resource assessment and forest management plan or update an existing one. An example management plan by County Forester AJ Follensbee is the Crawford Town Forest Resource Assessment and Forest Management Plan.

Review Town Policies, Ordinances, and Staff Responsibilities for Hazard Trees

Before implementing any management strategies to address EAB, confirm or establish who will oversee management of infested ash trees in your town. Identify how your municipality already manages risk trees in public rights-of-way and highly trafficked areas. Review and update regulations to ensure that the municipality can respond quickly and effectively to an EAB infestation.

Ask your town manager or town clerk if the municipality currently has policies regarding tree management and how trees within the town forest might fit into these existing municipal policies. If additional clarity is needed, consult with your town attorney to understand what a reasonable duty of care means for your municipal forest. If your town does not have an attorney, consult with the Municipal Assistance Center at the Vermont League of Cities and Towns.

4. Assess Existing Ash Trees

Assess Abundance and Distribution of Ash

Ash trees make up 5-7% of trees in Vermont’s forests, but in certain localities, ash may comprise 20-70% of all trees. In developing an EAB management plan for your town forest, you must assess the abundance, location, and condition of all ash trees. If your town forest already has a management plan, then the abundance (expressed as a percentage of the trees on the property) and distribution of ash trees may be detailed in this document. If the impact of EAB and ash tree distribution is not in the existing plan, then it can be amended, likely with select board (and VLT staff, in the case of VLT-conserved parcels) approval. Basic ash inventories can be conducted by volunteers or student groups, but forest inventories and the drafting of the detailed forest management plan should only be done by a Vermont licensed forester. 

Keys to identifying the three native species of ash trees in Vermont are available at VTInvasives.org.

Assess Condition of Individual Ash in High Use Areas

Depending on the situation, it may be appropriate to assess the condition of ash trees growing in high-use areas in your town forest, such as parking lots and picnic areas, lookouts, or popular trails, and to consider removing ash trees if they pose a significant risk to the public. Based on the goals and preferred format of your team, an assessment can be as simple as a paper record of the size and condition of ash trees marked on a hand-sketched map or as advanced as a GIS-based inventory.

5. Monitor Annually For Emerald Ash Borer

Annual monitoring will provide more specific, localized information regarding when the ash in your town forest becomes infested, how advanced the infestation is, and how it spreads. By the time there are noticeable signs of EAB infestation on the lower trunk of the tree, the larvae have likely been in the tree for several years. For this reason, it is important assess the current condition of ash trees in your town forest so that any changes are noted promptly and ash trees can be removed if deemed hazardous. There are three common tools for monitoring EAB: visual surveys, trap trees, and pheromone traps.

Post a Trailhead Sign (downloadable here). This sign will educate forest users about the signs and symptoms of EAB and encourage them to document and report any suspect trees on VTInvasives.org.

Visual Surveys

Organize a visual survey of high use areas such as trails, gathering spots, or parking lots. Fall and winter are often good times to do visual surveys because the tell-tale branch structure of ash trees is not obscured by leaves. Ask people to bring binoculars if they have them (helpful for looking for woodpecker flaking and cracks in upper branches), a camera or smartphone to take photographs of signs and symptoms, and a notepad to keep notes of tree locations. A handout of symptoms to look for can be helpful to share with volunteers.

Learn more about EAB signs and symptoms

Trap Trees

Trap trees are a method of detecting EAB when the population levels are relatively low in the landscape. Selected ash trees are manually girdled in the spring, and left standing through the growing season. This mechanical damage stresses the tree, causing it to release chemical compounds that make it attractive to the borer. The trap trees are cut in late fall and peeled to look for signs of the insect. To find out how to use the girdled trap tree technique, refer to the Landowner Trap Tree Protocol or watch this video from the Maine Forest Service. Girdling will kill the tree, so choose these sacrificial trees intentionally. If your municipality is interested in establishing trap trees on public lands, consult with your county forester to determine whether the proposed location and plan are appropriate.

Pheromone traps

Pheromone traps are plastic traps with lures that attract EAB. These traps are hung in trees in late spring and are periodically checked throughout the flight season. They are coated with a sticky substance that captures any insect that contacts the surface of the trap. To use this method, you must have access to someone who can distinguish EAB from all the other insects that will become stuck to the trap. Communities can order traps through several different places, such as AgBio or BioForest Technologies or Semiochemical.com.  Note that the green funnel traps must be taken down and checked every two weeks. 

You do not need to do all three methods, using any one method is better than not monitoring at all. The most effective monitoring program will include some combination of these three monitoring methods.

6. Make a Plan for Potentially Hazardous Trees

Once you understand your town’s current approach to managing hazardous trees, develop a plan to address potentially hazardous ash trees in the town forest that may succumb to EAB. Identify which ash trees pose a hazard, regularly assess those trees, and act to reduce or remove risk in a reasonable amount of time. Ash trees killed by EAB become very brittle and shatter in unpredictable ways, as is explained in this webinar by the Davey Tree Company on the hazards of EAB-infested ash trees. Proactive removals when trees are in good or fair condition will allow you to avoid higher costs and hazards associated with dead ash trees and spread the cost of removals over time. In this case, it can be helpful to develop a system for prioritizing trees for removal based on:

  • Proximity to high use areas or infrastructure (such as parking lots or picnic areas)
  • Size of trees

Be sure to include your county forester or consulting forester in these conversations, as some removal of ash near trails could be within the context of forest management prescribed in your town forest’s management plan.

7. Develop Your Town Forest EAB Plan

It is important that you talk with your county or consulting forester about creating a plan for managing the forest for emerald ash borer.

Research has shown that harvesting all ash in an area does not contain or stop the spread of EAB. On the contrary, cutting all the ash can reduce the chance of genetic resistance to EAB among both existing trees and future generations of ash. Conditions suitable for the regeneration of ash can and should be created within the context of responsible forest management while improving the health and resilience of your forest in general. 

Ash Management Guidance for Forest Managers covers most of the issues you will want to take into consideration when discussing how to manage the forest for EAB.

To manage our forests in a way that will allow for the benefits of potential genetic resistance, you should:

  • Retain large, healthy trees as sources of pollen and seed1
  • Retain healthy ash of all sizes and ages
  • Create group or gap openings that are large enough to recruit young ash seedlings and saplings

Manage Non-Native Invasive Plants

When the ash trees in your town forest die, they may create opportunities for the establishment and spread of invasive exotic plants such as Japanese barberry, common and glossy buckthorn, and shrub honeysuckle. If there are large amounts of invasive plants in your town forest, especially in areas with a high volume of ash trees, plan to control these plants before these ash trees start dying. Your forester can answer questions and provide support on how to get started with invasive plant control. Resources on specific invasive plants as well as tools to help assess and manage invasive plants can be found on VTInvasives.org.

For additional information on understanding the health of your town forest, consult Town Forest Health Check: A Town Forest Steward’s Guide to Forest Health Assessment by David Brynn and Vermont Family Forests.

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1Ash is dioecious, meaning that there are male trees and female trees. Only the female trees produce seed.  Good reproductive rates for ash require a ratio of 7:1 male to female trees. If your ash inventory is conducted in the late spring when both sexes of the tree are flowering, or in the late summer when the females set seed, it can include information about the sex of the ash trees in the forest. This information will help ensure that both sexes are retained in any forest management or chemical treatment program to promote a viable regenerating population of ash for the future.

8. Determine Your Budget And Timeline

Other important information will be cost estimates and timelines for different actions.  In some cases, you will have little control over the timeline. For instance, if EAB is already present in ash along trails and poses risk to the town forest users, these should be taken down as soon as possible. Before presenting a draft plan to the community, determine the following:

If you need funding for implementation, the Vermont Town Forest Recreation Planning Toolkit Grants and Funding Sources list may include useful sources to consider.

9. Present Draft Management Plan to Community

Once the draft plan is complete, the committee should present the plan to the select board and the community at large. This is an opportunity to share the results of the assessment and receive public input on decisions that must be made before the plan can be finalized and adopted. The Town Forest Recreation Planning Toolkit has many resources on developing and adopting plans for Town Forests and maximizing community engagement in the process.

10. Implement the Plan and Share Your Experience

The final phase is to implement the plan. This may include some harvesting of potentially hazardous trees, treating some high-value trees, and/or conducting forest management in partnership with a forester and a logger. It may also include some volunteer monitoring for EAB and control of invasive species. The Town Forest Recreation Planning Toolkit has additional resources on implementing plans for Town Forests.

Please Share Your Plan with Us!

To help us better understand management efforts and assist other communities in Vermont, please share your plan with us by emailing your plan to: Ginger.Nickerson@uvm.edu.