Section 2.2
Wetlands in the Forested Region
Summary of the area of wetlands in the forested region by wetland class with a description of the most common classes.
Total area of wetlands in the forested region: 28.6%
- Fen (also known as muskeg) is the most common wetland class, covering 17.3% of the forested region.
- Open water habitat (4.3%), swamp (3.6%), bog (2.6%), and marsh (0.8%) make up the remaining wetland area.
- Almost 25% of wetlands in the forested region are in protected areas.
Introduction
Forested areas in northern Alberta are covered extensively by wetlands—primarily peatland (bog and fen) complexes but also marshes, swamps, and open water.
These boreal wetland ecosystems are important for a number of reasons[1]:
- Boreal wetlands provide a diversity of habitats supporting a wide range of species, from amphibians to ducks and migratory songbirds to iconic mammal species like Beaver, Moose, and the threatened Woodland Caribou.
- Boreal wetlands function as water reservoirs, storing water to prevent flooding in wet periods and releasing water during droughts.
- Wetland vegetation absorbs and filters contaminants from the water, and helps minimize soil erosion.
- Undisturbed peatlands—the most common wetland type in the boreal forest—store large amounts of carbon that help to moderate climate change.
- Wetlands in the boreal forest are often highly connected complexes; these areas are vulnerable to development activities that alter or block water flow (such as roads). Boreal wetland loss is around 5.5% due to human development activities[2].
- Boreal wetlands are valued for recreation, tourism, and cultural activities.
In this section, we summarize wetland class and percent area covering the forested region in Alberta. We also highlight key wetland characteristics and species associated with the most common wetland classes.
Methods
- Wetlands in the forested region of Alberta were inventoried in the Boreal Forest, Canadian Shield, and Foothills natural regions, along with the Peace River Parkland Natural Subregion.
- Wetland locations were delineated using open source data and machine learning. Four classes of wetlands[3] were identified (bog, fen, marsh, and swamp) plus open water habitat. The open water habitat category includes shallow open water wetlands—i.e., areas that are less than two metres deep—but also includes open water areas, like lakes, that are deeper than two metres. Upland areas were also identified.
- Steps to identify and classify wetlands in the forested region of Alberta are listed below. For detailed methods see DeLancey et al. 2020[4] and ABMI 2021[5].
- Protected areas are defined as provincial protected areas (a list of the eight categories can be found here) and national parks.
Steps to identify and classify wetlands in the forested region:
- Open data sources of satellite imagery and a digital surface model (DSM), as well as known locations of classified wetlands[6], were used as computer inputs.
- Using these data inputs, the computer “learned” the characteristics associated with each wetland class, such as topographic position and vegetation properties, based on known wetland locations.
- Based on these characteristics for each wetland class, the computer created rules that were used to identify other possible wetland locations in the forested region. These rules were applied across this region to create an inventory of wetlands.
- Before finalizing the forested wetland inventory, known terrestrial areas as identified in the Human Footprint Inventory[7] were reclassified as upland.
- Finally, the inventory was reviewed at a 15 km x 15 km scale to fix obvious errors such as missing lakes.
Limitations and constraints:
- The Boreal/Foothills (forested region) Wetland Inventory project has an effective Minimum Mapping Unit of 1,000 m2. It is based on open source satellite imagery of 10-m2 spatial resolution from the years 2017–2018. The neural network machine learning approach excelled at delineating large fen and bog complexes, but did not capture as many small temporary marshes as the seasonal approach employed for the prairie region.
- The accuracy of the wetland delineation (i.e. identification of wetland vs. upland areas) is greater than the accuracy of wetland classification to the class level. The Boreal/Foothills Wetland Inventory classification has an overall accuracy of 85% compared to photo-interpreted validation data; however, most of the accuracy is from the distinction between upland and wetland, which is assessed at 95%.
- Out of the three regional wetland inventories, wetland classification by class was most challenging in the forested region due to the diversity of possible wetland classes and vegetation cover. The most common areas of confusion are swamp vs. upland, fen vs. swamp, and bog vs. fen. Refer to the technical documentation for more details on class accuracies.
The computer "learned" the characteristics of different wetland types—such as topographic position and vegetation properties—to identify wetland locations.
Results
Area of Wetlands in the Forested Region
Current wetland area in the forested region: 28.6%
Highlights
- In the forested region, wetlands are common, covering 28.6% of the area.
- Fen (also known as muskeg) is the most common wetland class, covering 17.3% of the forested region, followed by open water (4.3%), swamp (3.6%), bog (2.6%), and marsh (0.8%).
- 24.8% of wetland area is included in protected areas (32,576 km2 out of 131,348 km2); 18,956 km2, or 58% of the total protected wetland area, is in Wood Buffalo National Park.
- More than a quarter of the area of marsh (29.5%), open water (28.1%), and fen (26.3%) wetlands is in protected areas.
- Representation of bogs and swamps in protected areas is lower at 18.9% and 16.7%, respectively.
Distribution of wetlands in the forested region of Alberta. Click on the legend to turn wetland types on and off. Note: wetlands cover less area than what is displayed in the map.
More about wetlands in the forested region
Click on a tab for a description of the most common wetlands in the forested region. For more detailed descriptions of each wetland class, refer to the Boreal Wetlands Fact Sheets[1] and the Alberta Wetland Classification System Field Guide[3].
About fens in the forested region
- Fen is the most common wetland class, covering 17.3% of the forested region.
- Fens (also known as muskeg) are peatlands, which are defined by accumulations of at least 40 cm of organic material (i.e., remains of dead plants) known as peat. It can take thousands of years for peat to accumulate.
- These wetlands typically form expansive systems in flat, low-lying areas fed by flowing ground water or precipitation.
- More nutrient-rich than bogs, vegetation of these ecosystems can be grassy (open), shrubby, or treed along with abundant moss cover. Plants growing in fens get their moisture and nutrients from the peat.