Sampling wetland diversity is a bit like taking part in the Fort Boyard TV show. To get to the research location, you sometimes have to endure the blazing sun while dressed from head to foot in fishing overalls, cross oceans of reeds, brave fields of buckthorn or stinging thistles – and above all, be careful every step you take, unless you want to sink. But those conditions were of no concern to Audréanne Loiselle, a student-researcher doing a Ph.D. in ecology under the co-supervision of Stéphanie Pellerin, herself a researcher at the Jardin botanique.
Outside her doctorate, Audréanne seizes every opportunity to share the knowledge and experiences she accumulates with her feet in peat moss. Armed with exceptional communication skills, she’ll defend her “stinky waterholes,” as she affectionately calls them, at the 2022 international finals of the Acfas “Ma Thèse en 180 secondes” (My Thesis in 180 Seconds) competition this October 6. Enjoy this brief spell in the field with an adventurer of the marshes!
The ground that gives way beneath her feet
Audréanne remembers the odd time she was almost swallowed up by a bog.
By way of background, she explains that the bog structure is created by the alternation of plants that grow, die and accumulate, without being decomposed, forming a layer of organic material that thickens over the years. Sandwiched between the woods and the lake, the portion of a bog bordering a lake is a little like a mattress of floating mud. Between two observation points, Audréanne tests every step to see whether the soil will hold. The rare safe spots where the soil doesn’t risk giving way are made up of the suckers of plants, such as ferns, that always grow in the same place and create reliable mounds. Sometimes the young scientist jumps from one little knoll of ferns to another. At her peril!
“If you miss, you fall like into a muck hole. And if unfortunately the water gets into your overalls,” she jokes, “good luck getting out of that!”
She tells me that on one occasion, one of her legs sank in the muck up to her waist, while the other one remained above the bog. Holding herself on the surface thanks to a shrub she used as an anchor, she was finally able to extricate herself with the help of a colleague, who got her out of the mess with the end of a plastic quadrat. Another time, suction caused her boots to get stuck in the muck. She tells me that she was stuck standing upright on a ringed binder barefoot, getting out of her boots buried in the mud again thanks to suction… Even if they’re well equipped, biologists have to be on the alert. Wetlands are genuine obstacle courses!
Audréanne in the land of Oz
“When you’re the first person in a long time to set foot in a wetland, you see things that aren’t found anywhere else. You get to see their exceptional beauty.” Audréanne says this like a declaration of love for her field of research.
Wetlands contain a unique biodiversity, strange and fascinating. Ultricularia (bladderworts) – native carnivorous plants – rank with Audréanne favorites. Their strategy for capturing pray is amazing. The plant’s trap is located on a modified stem that floats right under the surface of the water. That stem has bladders, little submerged capsules. When a zooplankton comes close to it and brushes against the hairs bordering the opening of the bladder, the trapdoor opens inward and boom –water rushes in, sucking the plankton inside along with it and closing the door at the same time.
When the bladderwort is in bloom, it can be identified by its small yellow flowers. It flourishes especially in the depressions of pathways left by the repeated passage of beavers. Just like Dorothy in The Wizard of Oz, the student-researcher walks along these yellow brick roads, found exclusively in bogs.
So what’s the goal of her expeditions in murky water? Audréanne’s project aims to compare the characteristics and ecological services of three types of wetland: bogs, marshes dominated by shrubs, and marshes dominated by trees. Each of these three types fosters a different biodiversity. Sometimes it’s the diversity of fish that’s most prominent; other times it’s plants, birds or amphibians that abound. Ecological services also vary based on the wetland’s vegetation structure. For example, the greater the thickness of the peat, the more carbon is stored there. To maximize the conservation of the different ecological services, a variety of wetlands would therefore have to be protected.
“When I talk about wetlands, people often seem puzzled. It’s always funny to see their surprise when I tell them that there are several types of wetlands. Their amazement when I talk to them about ecological services – that’s the cool part!”
To learn more about Audréanne:
- National winner of the 2022 Acfas “Ma Thèse en 180 secondes” competition. Watch her performance (In French).
- Winner of the 2020-21 Acfas popularization competition. Listen to her research narrative titled “La symphonie des milieux humides” (The Wetlands Symphony) (In French).
Going a step further:
Every year in November, Space for Life presents Researchers’ Night, a unique event that celebrates research and brings down the walls between scientists and the public! Check our calendar for the next edition, on November 11, 2022, at the Jardin botanique.