Table of Contents
The trees that make Winchester a leafy suburb are in need of support. In fact, town has lost about 2.3% of its urban tree canopy in the last 13 years.
The Winchester Tree Canopy Assessment — done by the Permanent Street Tree Committee (PSTC) and Select Board — shows the canopy loss since 2012 equals about 90 acres or 68 football fields.
“We still have a reasonably good canopy over most of the town at this point in time, but it’s certainly going in the wrong direction. We need to do something to not only stop that, but hopefully improve it as well,” said David Miller, chair of the PSTC and chair of the Conservation Commission.
Miller said the town has lost almost 10% of its public tree canopy from 2018 to 2023.
Agricultural data and artificial intelligence
The PSTC, a town advisory committee, works with the Department of Public Works on care of Winchester’s public trees — trees in parks, schools and in conservation spaces.
The Tree Canopy Assessment was done by Colorado-based PlanIT Geo, using aerial imaging data from 2012, 2018, and 2023.
Funding was allocated by the Select Board from the town’s American Rescue Plan Act of 2021 (the COVID-19 stimulus). The report is available on the town website.
Aerial data is drawn from the USDA’s National Agriculture Imagery Program (NAIP), which identifies tree canopy, grass, shrubs, soil, impervious surfaces and water during peak growing season. The images are analyzed with machine learning and human evaluation to produce the data set.
This assessment includes public and private trees. The summary on the town website includes graphics that show how tree cover in specific areas of town increased and decreased over the study period.
Miller said the town is pleased with the report and it should be helpful with town conservation efforts, planning and public works.
The more trees, the better
Miller, a retired biologist and biochemist, said the more trees Winchester has, the better.
“There are a multitude of benefits they provide for human health, from shade and heat remediation, to wildlife habitat, to stormwater mitigation, to enhanced property values,” Miller said.
Having good data on the status of Winchester’s trees is an essential starting point, he said. Removing sick, dying or dangerous trees does need to be done, with an important caveat.
“The follow-on thought that has to happen is they need to be replaced. And that’s something that has not been happening,” Miller said. “It’s something which we hope we can use this data for to make the case.”
Sustainability Director Ken Pruitt said some residents do express concern that trees cut down for development and utility work are not being replaced. The town owes much of its charm to its tree canopy, he added.
Pruitt said tree planting and more thoughtful tree maintenance could offer solutions, and supports the town’s Climate Action Plan. The new report’s data, he said, could move the town’s conservation goals forward.
Two benefits trees offer from a climate perspective are their ability to pull carbon out of the air, and reduce neighborhood temperatures. During a heat wave, Pruitt said, there is a difference of several degrees between the temperature under a tree canopy and out in direct sunlight.
“As heat waves become more and more extreme with climate change over time, Winchester’s tree canopy is going to become even more important, not just street trees but all trees,” Pruit said.
How trees impact planning, development
Assistant Town Planner Ian Sexton said the Planning Board prioritizes preservation and public tree planting and in future developments. The new Main Street Mixed-use District, he said, requires public street trees for all new plans along the corridor.
“Any preservation [or] replacement of any trees that are necessary on site or on any budding public ways is always encouraged when we are dealing with developments, not just on North Main, but any other development areas,” Sexton said.
One of the places that indicated significant canopy loss in the study was the area south of the Mount Pisgah conservation area, where a driving range and golf learning center opened at the Winchester Country Club in 2016.
Miller said many of the trees lost in that process were replaced, but are younger and smaller trees, impacting current canopy size.
Pruitt added development does still have significant impact on Winchester’s tree canopy.
“I think people often think of Winchester as a community that is long since built out,” Pruitt said. “[People assume] there’s not a lot of development happening, and so there wouldn’t be a lot of trees being cut down for new development. And that really isn’t true.”
One reason for this, Pruitt said, is the high value of property in town means trees are cleared to make way for larger houses on existing lots.
“Oftentimes when a homeowner moves out of a smaller home, an old ranch home, for example, it gets torn down and turned into a much larger home. And the developers often just clear every tree on the property when doing so,” Pruitt said.
Action requires a budget
The PSTC hopes to help Winchester put tree growth “a little bit more on the front burner budget-wise,” Miller said.
The budget does include tree care, Miller added, but it is focused on removing fallen or sick trees rather than replacing these or expanding the tree canopy.
Growing trees does have a cost, said Pruitt, and new trees require care for two or three years after they are planted to fully establish.
“There’s a lot of trees that don’t make it in communities when there’s insufficient resources to keep them watered for those two or three years,” Pruitt said.
The PSTC is looking for community volunteers. At Spring Town Meeting in April, the PSTC will request to increase the number of at-large members on the committee from one to four.
