Follow this series to learn more about what wetlands are, their functions in the environment, their connection to people and the land, and wetland stewardship.
Wetlands are low lying areas of land where water covers the soil, or remains near the surface long enough to support aquatic or semi-aquatic plants and wildlife for part of their life cycle. They are highly diverse and productive ecosystems, and they are an important part of Alberta’s natural landscape.
Although wetlands are sometimes mistaken for shallow ponds, sloughs, or simply low spots on the land, they are distinct ecosystems. What makes a wetland unique is the presence of water long enough to shape the soils, plants, and ecological functions found there. Some wetlands hold water year-round, while others appear only seasonally during spring runoff or after significant rainfall.
Wetlands play an important role in sustaining healthy watersheds. They help protect water quality, store and slowly release water, support water infiltration, and provide habitat for wildlife, fish, and plants. They also help sustain biodiversity across the landscape. In Alberta, wetlands are estimated to support about 400 plant species, including some that are considered rare, threatened, or endangered in the province.
Wetlands are also more common than many people realize. Approximately 20% of Alberta’s surface area is covered by wetlands. More than 90% of these are classified as peatlands, which are wetlands that accumulate partially decomposed organic materials.
In Alberta, wetlands are generally grouped into five main classes, the classes described below are based on the Ducks Unlimited Canada’s Alberta Wetland Field Guide:
- Bogs are peat covered wetlands with poor drainage, acidic water, and low nutrient levels. They are often dominated by sphagnum mosses and shrubs and may also support trees.
- Fens are also peat covered, but they are influenced by groundwater flow. They are generally more productive than bogs and are often dominated by sedges, with some shrubs and trees.
- Swamps are dominated by shrubs or trees and may be flooded seasonally or for long periods. They are typically nutrient rich and productive and can occur as either peatlands or non-peatlands.
- Marshes are periodically or permanently covered by standing or slowly moving water. They are nutrient rich and support emergent vegetation such as reeds, rushes, cattails, and sedges.
- Shallow open water wetlands include potholes, ponds, and water along river and lake edges. These are usually small bodies of standing or gently flowing water and are often part of the transition between open water and marsh habitat.
Wetland types vary across the province. On Alberta’s prairies, wetlands are predominantly non-peatlands such as marshes and shallow open water ponds. In northern Alberta, peatlands such as bogs and fens are much more common.
Understanding what wetlands are is the first step in understanding why wetlands matter. These ecosystems do more than hold water, they support wildlife, improve watershed health, and contribute to the resilience of the landscape. These functions can also benefit agricultural landscapes by helping manage water, reduce runoff, and support healthy soils and surrounding ecosystems. In the next article, we will look more closely at how wetlands function as nature’s storage and filtration system.
Sources:
- Ducks Unlimited Canada. (2023). Alberta Wetland Field Guide. https://boreal.ducks.ca/wp-content/uploads/2023/11/AWFG-Web-Version-1.pdf
- Alberta NAWMP Partnership. (2022). Landowner Guide to the Alberta Wetland Policy: What is important to know before working in and around wetlands on your farm or ranch. Ducks Unlimited Canada. https://wetlandsalberta.ca/media/uploads/WetlandLandownersGuide.pdf
Image of a bog.
Shallow Wetland Vegetation Community.