In April the City of Hartford asked for help with their tree planting efforts. No, they did not ask for a bunch of kids who’d go out into the neighborhoods, digging holes, and planting trees. They wanted to know how many trees Hartford would have to plant in order to maintain its current canopy cover of 26% or to expand it to 35%.
This question is a little bit less straightforward than one might think, and the answer turned out to be a bit complicated. Luckily, we found Giles Lemmon (’21), who likes environmental problems and data crunching and had no current summer plans. We easily talked him into working as an intern for the City of Hartford. There he worked with Grace Li from the City’s Sustainability Office and Jack Hale, the chair of Hartford’s Tree Advisory Commission. Hartford’s trees follow a rather irregular age distribution, which means that the loss of large, mature trees is not simply compensated by planting an equal number of small trees. In addition, poor and spotty data made Giles’ job even more challenging.
Working with iTree, an open source software package developed in collaboration with the US Forest Service, Giles found that planting trees at a rate of 1000 / year would lead to a canopy loss of 440 acres (9 times the size of Bushnell Park) over the next 30 years. To maintain present canopy cover, he estimates that one would have to plant approximately 1500 trees per year, and an increase in canopy cover to 35% within the next 30 years would require an annual planting of approximately 7000 trees.