Photo: Wikimedia
A shady street in suburbia.
John has been working with the Arlington Tree Committee to inventory the town’s trees and promote the benefits of an urban canopy.
Recently, his team has connected with the lab of Lucy Hutyra, associate professor of earth and environment at Boston University, who plans to bring post-doc colleagues to Arlington to help determine the best planting strategies for combatting problems like heat islands.
A 2016 CityLab article about Hutyra’s research with BU biologist Andrew Reinmann notes that trees in urban and suburban environments actually do a better job of removing excess carbon dioxide from the atmosphere than trees in forests.
As Courtney Humphries reported at CityLab, “Forests are important asset in fighting climate change, absorbing an estimated 30 percent of the carbon dioxide we emit from burning fossil fuels. But those estimates come from big forests, says Reinmann, and we know relatively little about how patchy forests function, and whether they provide the same services that large forests do.
“A study published [in December 2016] in Proceedings of the National Academy of Sciences by Reinmann and BU environmental scientist Lucy Hutyra shows that forest fragments in New England behave differently than intact forests in surprising ways: they may pull significantly more carbon dioxide out of the atmosphere than predicted. …
“ ‘You can see how the structure of the trees all along the edge is different,’ [Reinmann] says, pointing to a stand of oaks with long horizontal branches reaching over the backyards, soaking up the additional sunlight. Slicing and dicing forests with housing developments, roads, and agricultural fields creates a multitude of forest edges and, as Reinmann and his colleagues are finding, conditions at the edge of a forest are different than deep inside it. These effects add up; currently, 20 percent of the world’s forested land is within 330 feet of an edge.
“Edge conditions can actually be a boon to the trees that remain. An earlier study from Hutyra’s lab found that urbanization makes trees in Massachusetts grow faster. …
“ ‘On, average the forest is growing 90 percent faster near the edge,’ says Reinmann. In some cases, individual trees are growing faster, and in other cases, they’re growing more densely. …
Given the growth boost at edges, Reinmann and Hutyra estimate, forests in southern New England take up about 13 percent more carbon dioxide than they’re given credit for, and store about 10 percent more carbon. …
“But, Reinmann says, ‘the really important thing to stress is that it does not mean forest fragmentation is a good thing. The carbon sink here is still substantially lower than it would be if we didn’t lose any forest.’ In other words, slicing up a forest to store carbon is a very bad idea.”
Click here for more, and here for the street tree map John’s team is building thanks to their Massachusetts Department of Conservation and Recreation grant.
Suzanne's Mom's Blog 
Thanks!
Very impressed with this work.
It seems sad that one would have to *work* at showing the benefits of trees in a city–how could they not be beneficial in a zillion ways?! But, since proof seems to be needed, I’m glad people like John are hard at work!