Baltimore’s retired arborist deserves much credit and many thanks | READER COMMENTARY

Historic Cylburn Mansion is in the background for recently retired Baltimore City Arborist Erik M. Dihle and the Baltimore Tree Trust's Amanda Cunningham when they teamed up to teach a class on tree car in 2019. File. (Brian Krista/Baltimore Sun Media).

One of Baltimore’s most effective public servants recently retired, and we should not let him go without publicly acknowledging his contributions and giving him a proper thank you. Erik M. Dihle was the city’s arborist from 2012 to 2022 and was responsible for all the trees in our parks and along our streets. That amounts to some 300,000 trees in all.

Erik moved Baltimore’s urban forest management from a reactive to a proactive methodology. Rather than only respond to citizen requests for service, Erik wanted to also manage the urban forest proactively according to the trees’ health. So he got all the city’s trees and vacant planting sites inventoried and mapped, a huge, multiyear endeavor. The forestry division now knows the species, location and health of each tree in the city and they use it to help management and planting strategies. They have made that information available to everyone (


He instituted a proactive pruning program in which whole neighborhoods of trees would be pruned in addition to the usual jumping around the city responding to individual service requests. This proactive method is more efficient and data shows there are fewer service requests coming from neighborhoods that have been proactively pruned. This means healthier trees and lower future maintenance costs.

He changed the forestry maintenance contract from a time and materials to a unit cost payment structure, another quantified leap in efficiency. The city pays for what gets done and each tree is priced based on its size and the type of work needed. Previously, contractors would be paid for their time spent in the field without a clear connection between that time and the amount of work accomplished.


And what to do with the mountains of tree trunks, branches and wood chips generated as byproducts? The city is now selling the wood chips as mulch, creating salable wood from the trunks and employing staff with the profits rather than relying on the city’s general fund.

The tree inventory, proactive pruning and wood reutilization were not in the general fund budget. Erik is the only manager at Recreation and Parks who routinely wrote grant proposals and won funding from City Hall to bring his visions to reality. He nurtured partnerships with the U.S. Forest Service, local nonprofits, and community groups that helped get the wood re-utilization project off the ground as well as measure and grow the city’s tree canopy by targeting tree plantings in high-need areas.

Erik fortified his invasive vegetation management team and dedicated staff to try and hold accountable the many clumsy stream “restorations” and sewer reconstruction efforts that threaten Baltimore’s stream valley parks.

Finally, Erik was a successful and respected leader. Against the constant headwinds of budget cuts and departmental bureaucracy, he worked harder than anyone to grow the size and skill of his staff. They are smart, dedicated and diverse, and they liked working for him. Colleagues and elected officials liked working with him.

There is no shortage of coverage in the Sun of mismanagement and corruption in government agencies. Erik M. Dihle and his team in the Forestry Division accomplished great things and we owe him a big thank you.

— Bill Vondrasek, Towson

The writer is a former Baltimore parks official.

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