By Pete Whittington, PhD (Associate Professor at Brandon University, Dept. of Geography and Environment) and Maria Strack, PhD (Professor at University of Waterloo and Canada Research Chair in Ecosystems and Climate Geography and Environmental Management)
Peatlands are important global stores of carbon. They store more carbon than the world’s forests combined, despite covering only 3% of the Earth’s surface. Peatlands also occupy about a third of Manitoba’s land area. Despite these impressive facts, most people don’t even know what a peatland is!
To understand peatlands, we first need to know what a wetland is. A wetland is an area of land that has plants and soils that are adapted to a wet environment. Wetlands in Canada are either mineral wetlands, such as marshes, swamps, or shallow open-water, or organic wetlands, more commonly known as peatlands.
A peatland is a special type of wetland that accumulates organic matter, which we call peat. Peatlands are usually broken into two groups: bogs and fens. Bogs get their water only from rain/snow, whereas fens can get their water from streams, groundwater, as well as rain/snow. Because of this, Manitoba’s peatlands are found in the eastern, Interlake, and northern parts of the province; it’s simply too dry in Westman for peatlands!
Above: Bird's Eye view of the peat restoration site (photo by Pete Whittington)
Over 1000s of years, some fens turn into bogs because of biological and ecological processes that favour acid-loving vegetation, like Sphagnum moss. The pH of a bog can be as low as 3.5.
A very small percentage (0.03%) of these peatlands in Canada, typically bogs, are used to produce horticultural peat, the ‘peat moss’ that you can buy at garden centres, which is used to grow vegetables and flowers in your garden, or commercial greenhouses. Once the peat with good horticultural characteristics has been extracted, the sites need to be restored so they begin to store carbon again.
Thanks to decades of collaboration between university researchers and the Canadian peat industry, Canadian researchers are recognized as world leaders in bog peatland restoration. We want to extend this knowledge to fen restoration since fens are very common in western Canada. We believe that it sometimes might make more sense to restore these horticultural sites to a fen, given that the peat remaining in the field would have originally been from a fen. However, we know very little about fen restoration in Canada.
Because fens have a more complicated hydrology (not just rain-fed like bogs) we need to create pathways for water and nutrients to flow from the surrounding area into the restoration area. We plan to do this by creating an ecotone, or a transition zone, between the two areas. How do to this, however, is also not fully understood!
Above: L to R: Haley Lobreau (student in the MELS program at BU), Michael Falufosi (student in the MELS program at BU), Pete Whittington, Frank Yamoah (student in the MELS program at BU), (photo courtesy of Pete Whittington).
Our research aims to address these two unknowns: fen (rather than bog) restoration and ecotone creation. We plan to restore part of a peat extraction site in southeastern Manitoba using different approaches. The aim is to retain as much water on the site as possible so that fen plants can establish on site and start storing carbon.
One such approach is to use furrow-diking, to create small ridges and depressions to retain snow/rain and prevent runoff. We are also going to spread straw-mulch across parts of the fields to lower the evaporation from the fields. The straw reflects a lot of the sun’s energy, so the dark peat doesn’t heat up as much. We will also experiment with different types of slopes to encourage the flow of water and nutrients from the undisturbed peatlands to the restoration area they surround.
We’ll assess which methods work best by quantifying the water and carbon cycles in the different approaches used. Those that retain the most water and store the most carbon will be the preferred methods.
Funding for this project is through a Natural Sciences and Engineering Research Council (NSERC) Alliance Grant, which encourages university researchers to collaborate with partner organizations, in this case, the Canadian Sphagnum Peat Moss Association and their members, especially Sun Gro Horticulture where the research will take place. The results of these findings will be shared with the association and transferred to their members to be applied on their production sites.
Peatland restoration, like many environmental issues we face today, requires an integrated approach, that is, a team of experts working together who understand just how interconnected and complicated the hydrological, biogeochemical and ecological processes are in these globally important ecosystems.
Since Canada contains more than a third of the world’s peatlands, it’s critically important that we use these resources responsibly, and a good part of doing that is successful restoration after their use. Peatland restoration is never as simple as just flooding a field!