More than 2,000 trees dot University of Pittsburgh’s campus, and two Pitt students have made it their mission to document every single one.
The ambitious project began when Tom Eliseuson, a 70-year-old student in Pitt’s Osher Lifelong Learning Institute with a love of dendrology (the scientific study of trees), wondered if the university had a tree inventory.
“I wander around the campus going to classes, and I’m looking at the trees,” he said. He contacted Pitt’s facilities department this summer, and when he found out that no such inventory existed, he volunteered to do it — for free.
Facilities connected him with Madison Holden, a 20-year-old undergrad studying biology, who works as the department’s student sustainability intern. Passionate about the environment, Holden had studied the inventorying process in an ecology lab.
The university, meanwhile, already was working toward increasing the tree canopy by 50 percent by the year 2030 as part of a larger commitment to sustainability, said Rich Heller, senior manager of electrical utilities & energy initiatives in Pitt’s facilities management division.
Given those goals, he said, Pitt had been talking about the need for a tree inventory to document the trees on campus and determine if any invasive trees needed to be removed.
It was as if Eliseuson “fell from the heavens,” Heller said, referring to his “out-of-the-blue” phone call.
So far, the pair has identified 1,800 trees of an expected 2,500, including some that pre-date the university and others with intriguing backstories. The team started in July 2018 and plans to finish by summer’s end, working straight through the winter to create the university’s first tree inventory in recent memory.
How to inventory trees
First, the team divided the campus into sections using a map.
Then, Eliseuson heads into the field with a clipboard, a data collection sheet, and a map, wearing a Pitt cap he had embroidered with the words “Tree Inventory” on each side.
He examines each tree to determine the following:
- GPS coordinates, calculated by Garmin or cell phone — or sometimes the old-fashioned way, by pacing the coordinates
- Scientific name and common name, determined by examining the tree’s bark, leaves, flowers, or fruit
- Diameter in inches, using a special measuring tape
- Height in feet, calculated with a Theodolite app or by estimation
- Estimated age in years
- Condition, ranked from 1 to 5 (5 is bad/dead, 4 is poor, 3 is average, 2 is good, 1 is really good)
- Type, such as native, ornamental, or invasive
Eliseuson, a self-proclaimed “tree guy,” compiles the information, carefully noting it on his data collection sheet.
The topography determines how long data collection takes. On flat terrain, Eliseuson can inventory one tree every five minutes, but hillier wooded areas are “a whole different ballgame,” he said.
Once he finishes a section, he turns over the pen-and-paper records to Holden who moves the data online into Excel and Google Earth. Holden joins in on the fieldwork when possible.
“I like that the project involves students instead of contracting out another entity to do this,” Holden said. “Its students being accountable for their campus.”
For Eliseuson, studying trees has become a retirement hobby. He’s conducted similar tree inventories at local golf courses and botanic gardens.
While the map is being used internally now, Heller hopes to eventually make it public for anybody to search, which would be especially helpful for student groups interested in sustainability.
“We really like to celebrate the things that we have on campus,” Heller said. “That’s one of the things I think is really cool — the history of these trees. Because if you know about them, that will help protect them.”
Why it matters
The tree inventory will make clear what kinds of native and invasive trees can be found on campus and “give a bigger picture of what types of trees thrive in the area,” Holden said.
A tree inventory was done years ago, but Heller said he’d ever only heard rumor of it, and an updated inventory will help guide development on campus. For example, when trenches need to be dug for lighting projects, the facilities team checks their tree inventory to determine which trees might be affected, protecting certain trees and removing invasive trees.
“It’s already proving beneficial to us,” Heller said.
Having a tree inventory is also crucial for the university’s sustainability plan, Holden said. Working toward its tree canopy goal, Pitt planted 92 trees so far this year, Heller said, adding that an increased tree canopy will help clean the water and air; assist in stormwater management; and improve health and well-being.
The tree inventory will need to be updated in five to 10 years, Holden said. By then, many more trees will be on the list.
“Students do better in their classes when they have trees to look at,” Heller said. “Being here in Oakland with Forbes and Fifth Avenues, we have a lot of diesel fumes, and trees help.”
Trees can also be planted on steep hillsides, he said, meaning facilities crews won’t need to mow those areas — both using less energy and making safer work environments.
“We learned that neighborhoods tend to be calmer and safer when there are trees,” Heller said. “You can’t have too many trees in my opinion.”
Pitt’s peculiar trees
Though the Oakland campus may seem like an urban environment, it also includes several wooded areas near the Falk School and Petersen Event Center. Those are areas where “trees weren’t planted. They were there and grew on their own,” Eliseuson explained.
Throughout the campus, interesting trees pop up just about everywhere, whether they were planted by hand or by fate.
The most surprising?
Thought to be extinct, the dawn redwood was known only by fossil records until the 1940s. Then, one was discovered in China, and Yale researchers visited to bring seedlings back to the United States. Pitt has one, dating back 60 to 70 years.
“The dawn redwood is a special tree. I think they have one of the very earliest dawn redwoods,” Eliseuson said. “They do get to be big, big trees — not as big as the redwoods in California.”
Both students count the dawn redwood, located just outside of the Cathedral of Learning facing toward Heinz Chapel, among their favorite trees on campus.
The most common?
Northern red oaks and sweet gums.
“This area around the Cathedral here and the Student Union is where the old park-like trees are,” Eliseuson said. “There’s some really amazing trees in this area.”
There are a few contenders stretching to 100 feet: Red oaks, ginkgoes, and American elm.
“There’s a few that are battling it out,” he said, noting that it’s rare for an American Elm to have survived and thrived after Dutch Elm disease wiped out so many.
Look for the American Elm on the Cathedral lawn, where you can admire its graceful branches and crane your neck to see the leaves at the top.
Campus is home to ginkgoes and oaks dating back 200 years, though Eliseuson notes that measuring tree age is an inexact science based on a diameter test. Even so, he said, old trees can be found on northern part of campus, near Schenley Farms.
Stately oak trees can be found lining Fifth Avenue on the Cathedral of Learning lawn, and keep an eye out for ginkgoes across campus — they’re the ones with the yellow fan-shaped leaves that drift to the ground each fall.
“There are some big, old trees up there — 200-year-old ginkgo trees,” he said. “They were around before the university was here.”