Amid rising global temperatures and intensifying heatwaves, wetlands are among Earth’s essential natural defences. However, Canada’s Prairie Pothole Region (PPR) ecosystems are under threat from decades of drainage and agricultural expansion that have turned much of the landscape into cropland. This shift reduces their capacity to store carbon and regulate the climate, posing serious risks not only to the environment but also to local and regional agricultural economies.
A recent study published in Agricultural and Forest Meteorology details these concerns as it explores how wetland conservation can help mitigate heat stress and support the agricultural environment across the Canadian Prairies. Joyson Ahongshangbam, lead author on the study and postdoctoral researcher in McGill’s Department of Geography at the EcoFlux Lab, explained the motivation behind the research.
“We are working on understanding different ecosystems, especially the wetlands, and other ecosystem services provided by wetlands across different parts of Canada,” Ahongshangbam said in an interview with the Tribune. “We have many study sites in Vancouver, Manitoba, and […] Quebec.”
The study, conducted in southern Manitoba, explores how different wetland types within the PPR contribute to surface cooling. Researchers dive into how vegetation, water coverage, and surrounding land use influence this effect. By quantifying the temperature regulation potential of these ecosystems, the findings provide insight into how conserving and restoring wetlands can counter the growing heat stress across Canada’s agricultural heartland.
The team focused on three wetlands: An isolated cropland marsh (CA-EM1), an isolated grassland marsh (CA-EM2), and a restored marsh (CA-EM3). Two additional cropland sites served as reference points: An organic cropland (ORG) and a conventional cropland (CON). Each site differed in size and vegetation type. Researchers used Eddy-covariance technique—a method that measures the exchange of heat and moisture between the land and atmosphere—to compare the sites.
“[This technique] is a micrometeorological technique using a set of instruments. The gas analyzer measures gas concentration at a very high frequency, […] [and] the anemometer measures wind speed and direction in three dimensions. We apply micrometeorological methods to measure concentrations of gases like CO₂ or methane, with vertical wind speed, to understand how gases move,” Ahongshangbam said. “From this, we calculate how much carbon is going from the ground surface to the atmosphere, or vice versa, estimating annual or multi-year carbon budgets and storage. For energy fluxes, we measure net radiation from the sun and track how it transfers into various energy components. Some energy reflects to the atmosphere, some is stored in the surface or water, and some transfers through evapotranspiration.”
Results showed that wetlands provide daytime cooling, though to varying degrees. CA-EM1 had the strongest effect, averaging 3.0 °C lower temperatures, while CA-EM2 and CA-EM3 showed smaller reductions of 1.4 °C and 1.5 °C, respectively, confirming wetlands in the PPR can lower summer temperatures by up to 3 °C. Wetlands act as natural buffers, cooling the air and reducing crop stress.
The PPR’s wetlands can help combat the climate crisis. By significantly lowering local temperatures, especially on hot summer days, these ecosystems should be central to Canada’s climate adaptation strategies. Wetland conservation and restoration not only enhances cooling but also contributes to long-term carbon balance and ecosystem stability. The research also emphasizes the need to manage vegetation and hydrology for both climate and agricultural benefits.
“I hope this paper inspires stronger conservation policies,” Ahongshangbam said. “By expanding our work with remote sensing, we aim to show just how far the cooling power of wetlands can reach, and how vital they are to Canada’s climate future.”
