One of the trees in Dr. Mark Vanderwel’s research plot that was tagged years ago. (Photo by Trevor Hopkin)
Driving down a bumpy dirt road that’s impassable when wet, the white field truck stands out against the blue Prairie sky and green native grasses. A University of Regina biology research team clambers out of the work truck, grabs their gear, and heads into the forest.
Scrambling over fallen logs, moss, and tree roots, through a forest in Southern Saskatchewan’s Cypress Hills, Dr. Mark Vanderwel and his team make their way to the centre of a tree stand and prepare to collect data as part of a decades-long project. It’s an adventure just getting to their research plot.
Dr. Anna Crofts clambers over a dead tree as she hikes into the research plot to collect data. (Photo by Trevor Hopkin)
Drought and drones
Dr. Anna Crofts, a postdoctoral fellow at the U of R, is this summer’s project lead. Working under the supervision of Vanderwel, her research applies drone-based imaging to study how trees in the region are responding to drought.
"I am looking at how the growth rate of trees has changed over time in this increasingly water-limited region. Not only how different species are affected, but also different individuals withing the same species. A very tall white spruce, for example, might be more or less sensitive to drought than a shorter white spruce, because their physiology is different."
A global connection
It might seem like a hyper-local question. Why does it matter what happens to trees in Cypress Hills?
For Crofts, the connection is global.
“The earth itself is a global biome,” she says. “Forests across the globe contribute to the services humanity depends on, especially carbon storage. The Cypress Hills is a climate-sensitive forest, so if the ability for trees to grow and survive here changes, there are global implications because of this forest’s role in carbon storage.”
Drought-sensitive forests in Saskatchewan could indicate broader threats to carbon sequestration, potentially exacerbating climate change writ large.
Decades of data
Crofts’s work builds on a decade of data collection led by Vanderwel, an associate professor in the Department of Biology. He came to the University of Regina ten years ago, drawn by the chance to establish a research program rooted in Western Canada.
Dr. Mark Vanderwel writes down data about the trees that the research team relays to him. (Photo by Trevor Hopkin)
“When I saw an opening for a plant ecologist, it gave me an opportunity to develop a program focused on the boreal forest and places like the Cypress Hills, which I already had an affinity for,” he says.
The Cypress Hills are about 600 metres above the surrounding prairies and were one of only a few places not completely covered by ice during the Wisconsin glaciation period, giving them a unique climate and habitat. The vegetation is a mixture of fescue grassland, lodgepole pine, white spruce, balsam poplar, and trembling aspen.
Dr. Anna Crofts tags a tree. (Photo by Trevor Hopkin)
Tagging trees, tracking change
Back in the forest, Crofts takes out a small silver tag, about the size and shape of an army dog tag. She wraps it around a small tree, tagging it so future researchers can trace its lifecycle:
How tall will it grow? How wide? How old is it? How long did it live?
The researchers often have to act like detectives, searching high and low for trees that were tagged in the intervening years. Some of the tags are now hidden amongst deadfall. Some have grown into the trees and can no longer be read.
Learning in the field
Croft’s dog, Willow, who tags along on most of her field work adventures, helps out by running around and nipping at the tape measure that two undergraduate field assistants use to measure the circumference of a tree, crucial information that lets the team know how much an individual has grown since it was last checked.
Like today, this summer’s field season will be spent in the forest, working with individual trees. The team will also spend time flying drones over the tree canopy in search of answers—about trees and about drone technology.
“Drone-based data collection is still relatively new, and the technology is constantly improving. So, the data set that’s been collected at the Cypress Hills is important and valuable because it spans ten years, starting in the infancy of drone data collection to today,” says Crofts. “Having ten years of drone images and ground-truthing data from Cypress Hills is a rare opportunity.”
For students like Atom Yetowski, a fourth-year biology student whose work with the team this summer was funded by a Natural Sciences and Engineering Research Council award, that data collection is both demanding and eye-opening.
Atom Yetowski measures the circumference of a tree. (Photo by Trevor Hopkin)
“We measure tree height, diameter, and whether the tree is alive or dead—and there are different categories of dead,” he says wryly. “We also fly drones to capture canopy images. These are long days, but I’m learning skills I’d never get in a classroom, like navigating with a compass or working as a team deep in the forest.”
Fellow researcher, second-year undergraduate student Dilman Gill, whose fieldwork is supported by the U of R’s Faculty of Graduate Studies and Research, agrees. “I’m usually indoors studying, so this has been a big adjustment,” she says. “You get so much exercise, you have to solve problems on the fly, and you also learn independence—cooking your own meals, managing your time, living as a group. These are life skills I wouldn’t get if I was just sitting at a desk taking notes.”
For Vanderwel, this kind of hands-on training is as important as the research itself. “You bring students out here, and for some it’s their first time spending a summer in a wilderness park,” he says. “It’s rewarding to see them develop new skills, discover the ecosystem, and maybe even start imagining careers in this field.”
Dry years
Over the past decade, Vanderwel and his students have tracked the fate of Cypress Hills’ trees in permanent plots, combining field surveys with drone-based canopy studies. This kind of long-term data allows Vanderwel to spot trends.
Dilman Gill uses measuring tree height using a vertex, which uses trigonometry to take that measurement. (Photo by Trevor Hopkin)
Going back a century, he says the past five years have been among the driest on record for the area, and Vanderwel’s data shows the consequences. “Mortality in white spruce and trembling aspen has doubled following these dry summers.”
Scaling up with drones
For Crofts, Vanderwel’s decade of data provides the perfect testing ground for her methodological work. “Our team’s findings can also help researchers from elsewhere, who are just beginning their data collection, refine and validate drone-based monitoring techniques, and help to establish standardized forest-monitoring protocols,” says Crofts, who over the past ten years has been involved with research projects exploring the alpine tundra in southwestern Yukon, the windswept forests of Newfoundland, and the colourful temperate forests of southern Québec.
Atom Yetowski, Dinesh Bhatta, and Dr. Mark Vanderwel flying the drone used to capture images of the trees in the Cypress Hills. (Photo by Trevor Hopkin)
The drones dramatically expand the scale of what can be studied. In one day, Crofts and her team might measure 120 trees by hand—a process that takes five or six hours. A 20-minute drone flight, by contrast, can capture thousands of images. Still, she notes, the technology has limitations.
“Quantifying tree characteristics, such as identifying a specific tree species, from drone images can be challenging, and ground surveys, actually being in the forest with the trees, are still essential for validating the data we collect from the drones,” says Crofts.
The heart of the research
An added benefit to working in the Cypress Hills is that the University of Regina has a field station located there.
The late George F. Ledingham, the former head of the University’s biology department, established the station in 1973. Located in the middle of nowhere, 65 kilometres southwest of Maple Creek in the West Block of the Cypress Hills Interprovincial Park, the field station sits on several hundred hectares of native prairie and forest on land leased by the University from the Province of Saskatchewan.
The University of Regina Field Station is in the West Block of the Cypress Hills Interprovincial Park. (Photo by Trevor Hopkin)
When he arrived at the U of R, Vanderwel knew little about the field station that would become the heart of his research. “Once I started the position and visited the landscape, I quickly realized how important it would be. Without the station, I probably still would have found a way to do research there—but the infrastructure meant I could focus on the science instead of worrying about where to house my students or how to recharge devices in the field.”
Thanks to recent funding, the field station got a complete overhaul.
Crofts and the undergrad students say the new Cypress Hills field station has transformed their work. “After a long day of hiking through the bush, it’s nice to have your own bunk to recharge and also a communal space to share meals,” says Atom. “The air conditioning doesn’t hurt either,” adds Dilman.
For Vanderwel, the station also represents continuity and change. The old facility, with its history stretching back decades, is gone. In its place is a modern space equipped to support the next generation of research. “It’s a little bittersweet,” he says. “But it’s exciting to know that what we’re building now will support science for decades to come.”
As for Crofts, still new to Saskatchewan, the experience has been more than academic.
“My first impression is just how beautiful it is here,” she says. “If anyone has the chance to visit the park, the historic site, or the field station, they should. It’s a special place.”
Watch the video for a tour of the new University of Regina Field Station:
Mapping the molecular secrets of E. coli
New funding helps unlock hidden networks inside bacteria
Read More