By Alex Pace, Brogan Stewart, and Leila Vaziri, PhD candidates at Concordia University

Last month, a few of my colleagues and I contributed to the Blitz the Gap project: a nationwide bioblitzing campaign to crowdsource information about local flora and fauna. We were lucky to be assigned Canada’s first provincial protected area as our blitzing area: Algonquin Park, established in 1893. I’ve heard of this Ontario gem for years but never mustered the energy to visit. It’s difficult to justify a six-hour drive past the beautiful mountains of Québec in favor of Ontario’s hilly, boggy terrain. Yet, hidden in Ontario are some of the oldest trees known in eastern North America—over 1800 years old—so the prospect of old forests and a weekend chasing after invasive plants with some environmentalist friends was the perfect motivation to finally check it out. We were not disappointed.

For this bioblitz, our team had three specific tasks: logging species at the far end of hiking trails, increasing the number of plants recorded in the region, and finding both invasive and rare native species. Equipped with the iNaturalist app and its Google-backed AI-assisted plant recognition, the first two tasks were relatively easy. The only real challenge there was for us to introduce my colleague Brogan’s two-year-old to hiking. Taking photos of the mushroom-laden forest floor with a baby on my back turned out to be the hardest part of the trip, but so rewarding. For our invasive and rare species mission, we hunted down the park naturalist for leads. The conversation was so engaging that I completely forgot to ask my questions about old-growth forests.

The naturalist enthusiastically marked our map with circles, Xs, and notes. The good news: only one invasive species had spread deep into the park—the Northern Dusky Slug, a Eurasian native that hitchhiked with canoe campers. Otherwise, most invasives were concentrated along roads and trails, which is to be expected. Of course, the Old Railway Bike Trail was a hotspot, with the charming tufted vetch and bladder campion plants dominating the invasive bunch. They are not particularly harmful to the ecosystem, so I let myself be charmed. Otherwise, an interesting “invader” was the American Chestnut. It had started to appear in the park recently, allegedly thanks to vigilante ecologists planting seeds, eager to restore the pre-industrial chestnut forests. The species is native to eastern North America, but here it is surviving outside its natural range. For anyone unfamiliar with the dominance and importance of the American Chestnut in the ecology and cultures of the northeast before the 20th century, I highly recommend giving this a read. Billions of these trees succumbed to a disease imported from Japan, arguably the most dramatic ecological loss in North American history. After that fascinating conversation, we pointed to another remnant of transportation infrastructure for insight on invasives: the abandoned airfield.

Contrary to my expectations, the airfield was effectively untouched by invasives. Usually abandoned fields and heavily disturbed landscapes are hotspots for invasive species from other continents that outcompete native species. The park decided that instead of letting the abandoned airplane runway rewild naturally, they would transform it into a regionally exceptional ecosystem, altering it with controlled burns every seven to eight years. The result is a landscape of low-bush blueberries, raspberries, sweet ferns, and lichen, apparently with a few gray pines—a fire-tolerant species. It has also become a hotspot for black bears, which flock to the berry-rich open field. Fascinating.

When exploring the site, I was reminded that human-altered environments have the potential to foster biodiversity and novel ecological value, and do not always lead to invasions and homogenization. It also resurfaced the Intermediate Disturbance Hypothesis for me—the idea that moderate intensity disturbances can increase biodiversity by supporting both early- and late-successional species. Carefully designed human interventions, in some cases, can function as such beneficial disturbances. Sometimes even by mistake!

Exploring the park through a camera lens and AI, learning about new plant species, and contributing to citizen science was a real pleasure. Over our few days of bioblitzing, we catalogued over 120 species and 1000 observations. Yet we found no particularly harmful invasives. Initially, I was fighting feelings of disappointment, of not achieving a mission, but when invasives are difficult to find, it’s a good thing!

Walking through old growth eastern hemlock forests and the tallest yellow birches I’ve ever seen, initiating a new generation to hiking, learning about weird ecosystems and chestnut vigilantes, and hearing eastern wolves howling and chattering at night all made the trip to good ol’ Ontario well worth it.

A huge thank you to the Québec Centre for Biodiversity Science and the Blitz the Gap team!

#blitzthegap #AlgonquinPark #invasivespecies #bioblitz #americanchestnut