For the first time in a decade, the Urban Forestry branch of Cambridge’s Department of Public Works has posted a map that lets residents and visitors see the colors of each city tree across the city as the leaves change.
The online Fall Foliage Map includes a colored dot for each tree that corresponds to the color the tree’s leaves will turn during peak foliage, as well as the tree’s common name, scientific name and diameter. Northern red oaks, for instance, are represented by deep red dots, while red maples are bright red dots, because of the slight difference how those trees present in the fall. European beeches get orange dots, because those trees turn bright orange in the fall, while river birches are dark yellow, American hollies are green because they stay that way year-round, and so on.
Although Urban Forestry chose each tree’s dot color based on its species, the map is static, meaning it doesn’t change as the season progresses. The colors were determined based on what the trees will look like at the point of peak foliage, though it’s a hotly debated topic in New England what moment is. Boston is one of the last places to hit peak fall foliage in Massachusetts, and this year, it was predicted to be at its peak Friday.
Creating the map
The project is organized by the entire forestry department, which was conscious that the last map appeared some 10 years ago, information systems manager Eric Josephson said.
“We had been wanting to bring it back for a while,” Josephson said.
The department started doing tree inventory in 2005, and now has a complete inventory of all the street trees with their species and locations throughout the city, which gets updated as trees are planted. (The map shows trees taken care of by the city, not trees on private land.)
“Now we’re just playing around with what information we can show the public that’s interesting and fun and creative,” Josephson said.
Urban Forestry plans to continue releasing foliage maps annually. Next year, Josephson said he would like to make the map more complex, with the size of dots proportional to the size of the trees they represent to create a more dynamic understanding for viewers.
“Ideally I’d also love to do two maps, an early foliage map and a late foliage map,” Josephson said. (This year, dots are based on the color each tree will be at the time of peak foliage, though, as Josephson mentioned, when that actually is is a hotly debated topic in New England.)
Other Cambridge tree maps
The detail with which Urban Forestry keeps track of each tree in Cambridge is what makes the Fall Foliage Map possible. Every time a tree is measured, pruned, gets a slow-watering “gator bag,” is treated for a problem or something else, it’s documented. All of that information is on the Tree Activity Map; users can click on any tree in the city and see its species and its history. A hardy rubber tree planted in Harvard Square on June 29, 2017, was measured Aug. 2, 2017, on June 12, 2018, and June 25, 2019, tracking growth from 2.05 to 3 inches. It was pruned on March 16, 2021, measured on June 22 and 24, 2021, and watered Aug. 8, 2021.
“We know where each tree is, what kind of tree it is, and what’s been done to it over time,” Josephson said.
In March, the arborists put together an interactive map of Our Favorite Trees – a cucumber magnolia outside City Hall, a weeping willow outside the Main Library and a London planetree in front of the King Open School, among others – and a fourth map tells you the species of the trees around it when it’s opened.
In May, the city published a flowering trees map that showed hot spots where numerous trees were in bloom at the same time. An updated version is due this spring, Josephson said.
The maps aren’t gathered anywhere so users can go directly from one to another. Nor are the maps easy to find on their own.
Still, Josephson said, “Cambridge does a fantastic job with urban forestry, and it’s nice to show it in a way that people can appreciate.”
A stronger
Please consider making a financial contribution to maintain, expand and improve Cambridge Day.
We are now a 501(c)3 nonprofit and all donations are tax deductible.
Please consider a recurring contribution.
when you document a tree, how long does it take to change your charting because it has been removed for development? What has been removed in favor of weak little saplings that don’t have the environmental power of a mature tree with big canopy? Have fun keeping up with removals for development.