Planning is one of the greatest means for landscapers to ensure the health of urban tree canopies. Using urban and community forest management to address emerald ash borer (EAB) issues can help provide for a future full of healthy urban trees. Whether making decisions within a homeowners association or a neighborhood, or making recommendations to individual clients, knowing the number, size and location of ash trees is the first step to sustainability.
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The interactive Colorado Tree View app is an online tree inventory tool that provides an EAB Cost Calculator, allowing landscapers and arborists to create what-if scenarios that assess the economics of management and treatment options for ash trees.
It is easy to get started at cotreeview.com/cotv. Click on the EAB icon, then the “Get Started” button. A prompt will ask for a general timespan to complete the project. For these examples, enter 20 years.
First, focus on one end of the spectrum—removing all trees to manage EAB. Under “Choose Management Activities,” enter information to remove 100% of the ash trees.
Under “Choose Your Ash Trees,” enter estimates for the number of trees to be removed. For these examples, we’ll consider 200 trees, all 12-18 inches in diameter. Leave the “Replanting” and “Treatment” boxes unchecked and click “Run.” Costs can be modified, but the default calculation is $6,500 per year, equating to $130,000 over 20 years.
If you choose to replant trees, the calculator can help with these costs as well. Using the same information as before, check the Replant box. The default calculation is the same for removal: $6,500 per year, $130,000 over 20 years. Planting is $2,500 per year, $50,000 over 20 years. Landscapers can easily see the total cost for this scenario is $9,000 per year and $180,000 over 20 years.
If residents want to retain all their ash trees, there are calculations to provide treatment instead. Choose “Treatment” for 20 years, with the same number and size of ash trees entered before. The default calculation is $25,500 per year, and $510,000 over the 20-year period.
Landscapers can print and save project-specific calculations as a PDF.
Making choices about ash tree management may start with economics, but there are always social and environmental considerations as well. Managing EAB involves a mix of these practices to match your jurisdiction’s goals. Perhaps minimizing costs, spreading costs over time, minimizing public safety hazards and liabilities, providing maximum canopy retention, and protecting natural resources and animal habitat are priorities. Existing inventory data, like the location of historic trees or important trees, can provide condition and proper placement information for important decisions and management considerations.
Colorado Tree View and the EAB Cost Calculator tool are valuable resources when used with additional resources like “The Colorado Emerald Ash Borer Management Plan Creation Guide,” created by the Colorado Emerald Ash Borer Response Team. Together, they provide comprehensive, supporting EAB management plan direction, no matter the size of the project.
Donna Davis is an urban and community forestry specialist for the Colorado State Forest Service. She holds Certified Arborist and Tree Risk Assessment qualifications from the International Society of Arboriculture; is a 2018 Municipal Forestry Institute Graduate from the Society of Municipal Arborists; and is a member of the ISA, Society of American Foresters and Colorado Tree Coalition.