Science Spotlight: Trees and the Urban Forest

The class gathered outside of Voter, looking up at the wire strung between two diverging trunks of an elm. “You see that wire, the slack there? In the summer, when the tree leafs out, it will pull the wire taught. That slack is a good thing this time of year,” explained Tim Parsons, Middlebury College’s Landscape Horticulturalist. The class, Trees and the Urban Forest, was in the middle of an outdoor lab and soon they wandered over to examine the root structure and corresponding lean of a sugar maple along College Street.

“All these sugar maples were planted at roughly the same time, and now they’re all dying at the same time. We took out one just down the hill last summer,” Parsons said, continuing with the lesson.

This is the second time Trees in the Urban Forest has been offered as a winter term course. Parsons first taught the course three years ago in the winter of 2010. The class, designed to be a broad interdisciplinary overview of trees, meets three days a week for two hours in a classroom, and then outside for a lab that runs several hours each week. They use the College’s campus tree menagerie of nearly 100 different tree species as its textbook.

“[The course] starts with tree biology, tree structure, and how trees grow. It moves into tree care, how to select and maintain them,” said Parsons. “Then we start stepping back a little further, and we look at urban forest design and the various impacts of trees in an urban forest. We’re going to fool around with some GIS work on tree mapping and how to maintain an inventory. I hope to get to some computer modeling of tree populations in an urban environment; there are computer programs now where you input a certain population of trees, and it will come back with the amount of carbon sequestration these trees do, the dollar amount for storm water abatement, for pollution absorption and energy conservation. When you start thinking about the roles trees play in an urban setting, they do quite a bit. It’s an interesting topic for a course because urban trees do so many things; you can bring a lot of different disciplines into the discussion.”

Graham Shaw ’16 wrote in an email: “Trees in the Urban Forest was a class I took on a whim. I've always thought trees are pretty and make nice additions to any landscape, but that was about the only thing pushing me into the class. Tim Parson's teaching has taught me a newfound appreciation for the importance of trees both aesthetically and environmentally.”

Katie Schide ’14 added, “Taking a class with Tim Parsons has been an incredibly unique opportunity. His passion for trees, especially those at Middlebury, is contagious. After just two weeks of class, I already see the campus in a completely different way. I think the whole class has gained a ton of appreciation for the tree maintenance and landscaping that happens on this campus everyday. So much care and planning goes into each tree on campus and Tim is at the heart of it all. When he plants a new tree, he is planning the landscape of campus for decades to come. This class has helped me gain a better appreciation not only for the landscapers, but for all the people whose work at Middlebury is often overlooked.”

Parsons moved to Vermont from his home state of Connecticut to attend the University of Vermont, where he graduated from in ’89. He co-majored in Plant and Soil Science (with a focus in Landscape Design) and Environmental Studies. After school, he worked in garden centers around the state, ran a garden center in New Haven, and worded independently in landscaping. He came to the College in 2006 to work in Landscaping Services as the College’s Landscape Horticulturalist. He also writes a blog called the Middlebury Landscape.
“Basically, I’m a tree geek,” he said with a grin.

One of the course emphases is on managing the various stresses on trees in an urban environment.

“We need our trees. We need shade. We need them for carbon sequestration. The question is: how can we manage and maintain our urban canopy to keep as many trees as we can as long as we can? If you take a tree away from its natural environment, you’re introducing different stresses to that tree. That’s a big part of what the class is about, how can you manage these trees and the stress of an urban environment to keep them as healthy as you can as long as you can?” said Parsons.

Trees at the College are exposed to numerous “stress factors.” They grow in impacted, compressed soils. They are exposed to high levels of salt run-off in the spring. In recent years, there have been numerous disturbing instances of tree vandalism. Just last Thursday morning, two small trees were found dug up and strewn across the sidewalk between Battell and Forest.

But Parsons wants his class to think beyond the College’s campus. To that end, the final project will involve urban forest management in the town of Middlebury. The emerald ash borer, a pest that kills ash trees, is progressing north towards Middlebury. Parsons and his class will fill out the State of Vermont’s Forest Pest Preparedness Plan, and map the ash trees that are within “striking” distance of town roads. Their final will involve submitting a proposal for the management of trees that are likely to be affected by the emerald ash borer to the town.

But the class has students thinking beyond Middlebury in other ways too.

“Beyond all of the interesting things I'm learning about trees and landscaping, being in class with Tim has made me more eager than ever to find a job that makes me happy,” said Scheide. “He comes to work everyday excited to be doing what he loves. Walking around campus with him, the list of his five favorite trees quickly becomes ten and he greets each one with a pat on the trunk.”