This summer, you are likely to find York graduate student Leslie Luxemburger under a tree. It’s not that he is sun shy. Luxemburger is taking an inventory of all the trees on Keele campus as part of a research project sponsored by the York Institute for Research & Innovation in Sustainability (IRIS) and the University’s Campus Planning & Transportation Department.
“We’re very interested in understanding the contribution that trees make to reducing carbon dioxide and combating climate change, and this project will enable us to get a good idea of how our campus trees might be affecting York’s ecological footprint,” says biologist and IRIS director Dawn Bazely.
In compiling the data for the IRIS project, Luxemburger (left) is using a special instrument called a tree caliper to measure girth. He is also measuring height and diameter, and making a note of the health of each tree. With a global-positioning-system instrument in hand, the environmental studies student can pinpoint the exact location of each tree.
The information will be analyzed and then compiled in a report by the sponsoring organizations. The findings will also be presented by Luxemburger at the Forests in Settled Landscapes conference at the University of Toronto on Aug. 20-23. The conference focuses on semi-natural parks, ravines and woodlots near urban centres and examines their ecological, social and economic benefits.
Luxemburger is just one in a long line of York students who has benefited from the learning opportunities made possible through the existence of four such semi-natural woodlots on the Keele campus. Each of the four – Danby Woods, Boynton Woods, Osgoode Woodlot and Boyer Woodlot – has a different topography, so each has a distinct microclimate and slightly different vegetation as a result. For example, the Boyer Woodlot (east of the East Office Building) gets more runoff from creeks and streams, so trees like poplars that do poorly in moist soil tend not to grow there.
Right: Woodlots dot Keele campus as seen from the air
Generally, though, the natural environment found within the lots is typical of many southern Ontario woodlots located within an urban centre. For this reason, they are good sites for students to visit and learn about the region’s characteristic flora and fauna.
“Generations of ecology and geography students have learned to identify trees on the York campus,” says Bazely. She reckons that over the 17 years she has been teaching at York, close to 1,000 of her students have done fieldwork in the woodlots and open fields on the Keele campus.
Bazely says she has found that the average height of the trees is declining. “We notice there isn’t much regeneration, unfortunately, which could be because the bigger trees that would have had the seeds are dying out." The trampling of small saplings by pedestrians could also be contributing to the problem, she says.
The woodlots contain up to 30 different tree species as well as shrubs and flowering weeds, including many non-native and invasive species, such as the European buckthorn. In addition, animals such as rabbits, groundhogs and increasing numbers of deer call the woodlots home.
Biology Professor Lawrence Licht also uses the woodlots as an outdoor laboratory. Each year, he goes into the woodlots with his fourth-year herpetology (the study of amphibians and reptiles) students to do research on the wood frogs. They count the number of frog-egg masses and then estimate the existing frog population by calculating that for every egg mass, there must be a breeding pair of frogs. Licht has been monitoring the wood-frog population in York’s woodlots for close to 30 years. The number of egg masses have fluctuated from 20-90 in one woodlot, he says, with approximately 85 in the last few years.
Similarly, biology Professor Bridget Stutchbury and her students in her animal ecology and ornithology courses are monitoring the black-capped chickadee population. “Each year, we visit all the woodlots on campus and catch and band as many chickadees as we can,” she says. Each bird caught is tagged with an official Canadian Wildlife Service-numbered leg band and two-coloured leg bands that identify the year of banding. Through their research, they discovered that “the chickadee population on campus crashed when the West Nile virus arrived from about 25 birds to only 12,” says Stutchbury. Since 2001, the population has gradually recovered to 20 birds.
Left: Aerial view of what is now Keele campus when it was farmland in 1958
More than a valuable research facility, the woodlots are a critical part of the ecological system. “They are really important for allowing migratory birds a safe place to rest and eat as they try to make their way through the GTA,” says Stutchbury.
The woodlots are also part of the Don River and the Black Creek watersheds. As such, they play a role in preventing floods after storms as water can seep into the earth in the woodlots, unlike in paved areas.
These forested lots pre-date the founding of the University and are remnants from the time when this land consisted of small fields farmed by individual families. At that time, says outgoing campus planner Andrew Wilson, farmers retained a portion of their land as woodland for water-control management. The woodlots also provided a source of firewood.
Four years ago, in homage to two of the pioneering families who settled the area, the University’s Board of Governors voted to rename the south Keele and north Keele woodlots – which abut Keele Street – Boynton Woods and Danby Woods respectively.
William Osgoode, the 18th-century chief justice of Lower Canada, is the namesake of the third woodlot, located south of Osgoode Hall Law School.
Boyer Woodlot was named after biology Professor Michael Boyer upon his retirement. During his time at York, Boyer inspired great enthusiasm for tree planting amongst students, faculty and the York community, says Barry Loughton, professor emeritus of biology and Boyer’s colleague. Boyer also chaired the arboretum committee. As a result of Boyer’s efforts, the woodlots were expanded and well over 1,000 trees were planted, says Loughton.
"The woodlots are part of the original fabric of the University,” says Wilson, “and they remain integral to the concept of York.”
Story by Olena Wawryshyn, York communications officer