Peatlands as Canada’s Carbon Keepers

By April Dalton

Canadian peatlands are one of Earth’s most important natural carbon sinks, covering more than 12% of Canada's land area and containing an estimated ~25% of the world's peatland carbon reservoir (Hugelius et al., 2020). These ecosystems are particularly dominant in the Hudson Bay Lowlands but also span large swaths from the arctic, sub-arctic, boreal plains to maritime Canada (Figure 1).

What Are Peatlands?

Peatlands are water-logged ecosystems where plant material does not fully decompose. This causes thick layers of peat (containing large amounts of carbon) to accumulate over time. These ecosystems are carbon sinks, locking away carbon that would otherwise be contributing to global warming. As a result, peatlands are highly important nature-based solutions for climate change mitigation.

Threats to Canadian Peatlands

This vast carbon store is under threat. The main causes for concern are related to drainage of these peatlands for agriculture and forestry – these activities help to convert the ecosystem into usable farmland but also release stored carbon into the atmosphere. Industrial development—such as mining and oil/gas extraction—also disturbs the land and disrupts carbon storage processes. In northern Alberta near Fort McMurray, for instance, oil sands overlap with peatland-rich regions.  Similarly, in Ontario’s Hudson Bay Lowlands (Figure 2), large-scale mineral extraction is planned in the so-called Ring of Fire—a region of globally significant carbon stocks.

How much carbon is stored in Canadian peatlands?

My work aims to improve our knowledge on the distribution of Canadian peatlands and their related carbon stocks using modern tools that go beyond traditional mapping. I am developing a more accurate calculation of carbon stock using high-quality empirical datasets (measurements of peat depth) as well as machine-learning techniques and remote sensing data.  

The first output of my work is a database of peat-depth measurements across Canada. So far, the peat-depth database contains 88,763 survey points, from 844 publications including government reports, academic journals and peatland inventories. Many of the peat-depth survey points were digitized for the first time (for example, Figure 3). Importantly, this compilation includes peat-depth measurements from environmental impact assessments. These datasets tend toward shallower peats in the range of 50-100 cm, and therefore represent transition areas, regions of shallow peat and/or forested peatlands that were not previously widely documented.

A second output of my work is a calculation of carbon stored in Canadian peatlands. To accomplish this goal, I will integrate information on peat depth, along with peatland predictors (i.e., climatic variables, soil water equivalent, surface radiation, terrain) into a machine learning framework to predict peat depth across the country. I will then incorporate carbon density data, and the end result will be the amount of carbon stored in peatlands across the entire country.  

Ultimately, my work aims to identify carbon ‘hot spots’ for prioritizing peatlands for conservation. This information is helpful for policy makers to incorporate peatland carbon calculations into federal and provincial carbon accounting and land-use planning.

Stay tuned

Interested in contributing peat-depth data or learning more about the carbon in Canada’s peatlands? Contact me at  dalton.april_sue@uqam.ca. You can also stay tuned to Can-Peat for many other projects related to Canadian peatlands.