Southern Ontario’s Ecoregions in Slow Motion: An Eight-Year Journey Along the Bruce Trail

Guest post by Daniel Stuart, MEnvSc Candidate in the Department of Physical & Environmental Science at the University of Toronto-Scarborough

During the final year of my undergraduate program the idea of hiking all 900-or-so kilometres of the Bruce Trail somehow lodged itself in my head. It was 2010 and I was twenty-one years old, immersed in the idealism of that age and on the doorstep of a career as an ecologist. At the time hiking from Queenston Heights along the Niagara River to the town of Tobermory at the northern tip of the Bruce Peninsula (Figure 1.) seemed an appropriate way to gain a more meaningful appreciation of my home province’s landscape. This would turn out to be true in part, but little did I know that the more valuable takeaway would be a practical education in the transitional ecosystems that define Southern Ontario’s landscape. For those without the time to hike it themselves, take a tour with me along the trail from south to north exploring its subtle but undeniable ecological shifts.

Figure 1: Bruce Trail Map (Bruce Trail Conservancy, 2020

As life sometimes goes, it was another two years before I finally purchased the Bruce Trail Reference guidebook and embarked on my first sojourn, a three day hike that would take me from the southern terminus of the trail at Queenston Heights back to Hamilton where I lived at the time. I hopped on a free shuttle bus heading for a casino in Niagara Falls and upon arriving was accosted by the bus driver when he spotted my backpack and water jug, realizing I had no intention of gambling that day.  It was September 2, 2012 and the first miles of the trail were peppered with sightings of uncommon shrubs and trees like Bladdernut (Staphylea trifolia), Sassafras (Sassafras albidum), Spicebush (Lindera benzoin), Pignut Hickory (Carya glabra), and Hill’s Oak (Quercus ellipsoidalis), many of which display full fruit in the late summer. These shrubs and trees share a common trait: in Canada they are confined to the Carolinan Ecoregion.

The Carolinan Ecoregion (defined as Ecoregion 7E in Ontario; Figure 2.) occupies the southernmost portions of Ontario, extending from the shores of Lake Erie to approximately Grand Bend in the west, London, Hamilton, and Toronto in the east. Named for the forests typical of the Atlantic Coast from Long Island to Georgia, this region is dominated by a large variety of deciduous (or, leafy) trees including those listed above that fail to thrive in cooler climates to the north or west (Colthurst & Waldron, 1993). In the Niagara Region the sheltering cliffs and slopes of the Niagara Escarpment offer a slightly warmer microclimate that encourages the region to “punch above its weight” in terms of plant diversity.

Figure 2: Ecoregions of Ontario (Crins et al., 2009)

My first journey from the Niagara River ended in utter failure when with painfully blistered soles, just 26 kilometres into my expedition I swallowed my pride and called a friend to pick me up at the Brock University campus in St. Catharines. I would eventually work up to 30- and even 40-kilometre days, but this would take years of training and a good deal of re-conditioning every spring to tighten up my legs that would seemingly turn to jelly each winter.

The “southern feel” of the Bruce Trail gradually diminishes as one hikes westward toward Hamilton, the conspicuously common open-grown oaks (Quercus spp.) gently replaced by the familiar Sugar Maple (Acer saccharum)-dominant woodlands that emblemize Canada. The extensive forested tracts of the Dundas Valley offer the final display of southern species before mounting the escarpment where suddenly one stands firmly in the Great Lakes-St. Lawrence Ecoregion (defined as Ecoregion 6E in Ontario; Figure 2.).  The abruptness of the transition surprised me. I recall spotting the northernmost stand of a southern tree, a population of Chinquapin Oak (Quercus muehlenbergii) perched below the escarpment brow next to Sydenham Road in Dundas. Although I understand that southern species are occasionally found north of the official boundaries of the Carolinian Ecoregion, along the Bruce Trail I encountered no other Carolinian-specialist plant. The sheltered valleys of the Hamilton area seem to provide a last bastion for southern plants that struggle to tolerate the exposed landscape above Burlington and beyond.

From the Burlington heights the Great Lakes-St. Lawrence forest extends northward all the way to the edge of the Canadian Shield, which itself transitions into the seemingly endless Boreal forest that blankets the northern part of our continent. Unlike the Carolinian region which comprises mostly deciduous trees, or the Boreal region which compromises mostly coniferous trees, the Great Lakes-St. Lawrence forest is a roughly equal mix of the two. This forest type features strong representation from leafy trees like Sugar Maple (Acer saccharum), American Beech (Fagus americana), and Black Cherry (Prunus serotina) along with their needled counterparts like Eastern White Pine (Pinus strobus), Eastern White Cedar (Thuja occidentalis), and Eastern Hemlock (Tsuga canadensis).

I hiked the central stretches of the Bruce Trail at a slower rate between 2014 and 2018, a section that traverses a hilly complex of woodlots, river valleys, and bucolic landscapes. I came across a Striped Maple (Acer pensylvanica) in the Caledon area and a small Jack Pine (Pinus banksiana) stand on a north-facing slope near the Hockley Valley, both typically northern trees. My first Northern Holly Fern (Polystichum lonchitis) was observed in Noisy River Provincial Park near the village of Creemore, a plant that in places coated the trailside by the time I reached Owen Sound. Similarly, I spotted a tiny American Hart’s Tongue Fern (Asplenium scolopendrium var. americanum) in the Beaver Valley, a globally uncommon species whose core range is concentrated around Owen Sound and the lower reaches of the Bruce Peninsula.

By May of 2019 I was hiking in earnest, setting aside many weekends to cover the approximately 210 kilometres from the west edge of the Beaver Valley near Kimberley, through Owen Sound and to the base of the Bruce Peninsula near Wiarton. The birding that spring was glorious, and I often hiked with binoculars somewhat annoyingly tugging against my neck. In the Beaver Valley I observed my first ever Louisiana Waterthrush (Parkesia motacilla) along the rushing banks of Bill’s Creek. A Philadelphia Vireo (Vireo philadelphicus) flitted between branches in a woodlot near Walter’s Falls, a Golden-winged Warbler (Vermivora chrysoptera) was spotted within a thicket at the Bighead River Overnight Rest Area, and a Green Heron (Butorides virescens) squawked at me near the Bognor Marsh.

In early September 2019 I began the big push up the Bruce Peninsula toward Tobermory, in a four-day period that would take me from the town of Wiarton to Crane Lake Road just before the southeast boundary of Bruce Peninsula National Park. Logistics were more complicated now and I was forced to consider packing lightweight provisions that were adequate but could still be carried on my back. There were also safety considerations specific to the Bruce Peninsula, like establishing a check-in system where cell reception was poor, and to keep aware of Black Bear (Ursus americanus) and the docile but not entirely unthreatening Massasauga (Sistrurus catenatus), Ontario’s only venomous snake. Bear scat was an intermittent sight along the length of the peninsula, first observed just 14 kilometres past Wiarton along Malcolm Bluff.

Although forests remained of mixed composition typical of the Great Lakes-St. Lawrence region, cool northern exposures and thin-soiled areas took on a palpable “northern feel”, often dense with Eastern White Cedar (Thuja occidentalis), pine (Pinus spp.) and Eastern Hemlock (Tsuga canadensis). Wind-beaten crags offered habitat for abundant Bearberry (Arctostaphylos uva-ursi), a northern species yet unseen on my journey so far, and Rattlesnake Plantains (Goodyera spp.) became commonplace. By the time I reached the edge of the National Park the Boreal woods felt much closer.

Sadly, poor weather and low spirits cut my hike short in September, with soggy feet and an approaching storm promising to result in a miserable finale. Despite this setback my goal to finish the Bruce Trail remains firm. At this moment I have booked a campsite in the National Park this May 2020 and (barring any disasters) myself, along with three companions, will finish the final 40 kilometres toward the trail’s northern terminus.

To walk the Bruce Trail is to walk a cross-section of Southern Ontario. For me it has offered an education in landscape ecology earned by traversing it first-hand. It has been a limit-testing and a character-building experience. Although I now hike with a different outlook than my 21-year-old self, I must credit him with having the guts to recognize the journey’s value and for accepting its challenge.

References

Bruce Trail Conservancy. 2020. Explore the Trail. Bruce Trail Conservancy. <https://brucetrail.org//trail-sections>. Retrieved 13 February 2020.

Colthurst, K., Waldron, G. 2013. “What is a Carolinian Forest?”. Essex Region Conservation Authority. Carolinian Canada. <https://caroliniancanada.ca/legacy/SpeciesHabitats_Forests.htm>. Retrieved 13 February 2020.

Crins, William J., Paul A. Gray, Peter W.C. Uhlig, and Monique C. Wester. 2009. The Ecosystems of Ontario, Part I: Ecozones and Ecoregions. Ontario Ministry of Natural Resources, Peterborough Ontario, Inventory, Monitoring and Assessment, SIB TER IMA TR- 01, 71pp.