OWA logo

You are here:Home»Publications»Featured Articles / News»Wetlands in Ontario

Wetlands in Ontario

Wetlands are lands that are saturated with water long enough to cause the soil to become waterlogged, and the growth of water-loving or water-tolerant plants to occur. Wetlands are transitional habitats, often forming the connection between aquatic and terrestrial ecosystems. They can occur where the water table is at or close to the surface, in low-lying locations, or along the edges of lakes and rivers. Many wetlands are permanently flooded, while others flood only periodically in the spring or fall. You can often walk through such areas in the summer without ever getting your feet wet!

There are four different types of wetlands in Ontario:

Black Spruce Bog by Sam Brinker WEBBlack Spruce Bog, Sam BrinkerBogs are peat-filled areas that receive their water and nutrients from rainfall. Peat consists of partially decomposed plants. Bogs are extremely low in nutrients and tend to be strongly acidic. They are typically covered with a carpet of sphagnum mosses. Other vegetation includes stunted black spruce trees, heath plants such as laurels and blueberries, and carnivorous plants such as sundews and pitcher plants. Bogs are extremely rare in the southern part of the province, though common throughout northern Ontario.

Fens, like bogs, are peatlands — that is, wetlands that accumulate peat. They are located in areas where groundwater discharges to the surface. Fens typically have more nutrients than bogs, and the water is less acidic. Typical fen vegetation includes sedges and mosses, along with some grasses, reeds, low shrubs, tamarack and white cedar, sundews, pitcher plants and orchids. While fairly rare in southern Ontario, fens are quite common in northern Ontario.

Fen by Darryl Mitchell WEBFen, Darryl MitchellMarshes are wetlands that are periodically or permanently flooded with water. Marsh vegetation typically consists of non-woody plants such as cattails, rushes, reeds, grasses and sedges. In open water marshes, floating and submerged plants such as water lilies and pondweeds can be found. Marshes are fairly common throughout Ontario, with the most productive ones occurring along the shorelines of the southern Great Lakes.

Swamps are wooded wetlands that are often flooded for a portion of the year. Swamp vegetation is dominated by trees, including both coniferous and/or deciduous species, and tall shrubs, such as willows, dogwood and alder. Common throughout Ontario, swamps are incredibly diverse, exhibiting a wide array of vegetation, age and ecological settings.

It may be difficult to tell whether you have a swamp or a forest on your property, as some forests may contain wet soils and pools of water at different times of the year, and many water-tolerant species of plants are capable of growing in drier conditions, characteristic of a regular forest. In the most general sense, swamps are wooded wetlands with 25 percent cover or more of trees or tall shrubs. In swamps, standing to gently flowing water occurs seasonally or persists for long periods on the surface; frequently, there is an abundance of pools and channels.Marsh2 by Darryl Mitchell WEBMarsh, Darryl Mitchell

Swamps include both forest swamps (having mature trees), and thicket swamps (dominated by shrubs and/or small trees). Thicket swamps are characterized by thick growths of tall shrubs such as willow species, red-osier dogwood, buttonbush and speckled alder. Forest swamps may be hardwood swamps, typically containing silver/red maple, white elm, black/green ash, and yellow birch; or conifer swamps, where you will find species such as white cedar, eastern hemlock, tamarack and black spruce.

Forests that are not classified as swamps may have temporary pools of water, or channels, but they will be dominated with non-water tolerant or upland plant species. The best indicators are trees like sugar maple, beech, basswood, black cherry, walnut, white pine and jack pine.

Coniferous Swamp by Darryl Mitchell WEBConiferous Swamp, Darryl MitchellVernal pools, while not classified as wetlands, are temporary pools of water found in forests, which range from puddles to ponds. They appear in the spring from snowmelt or heavy rains or as a result of a high water table. They are found in small depressions in the forest and generally have no defined inlet or outlet. These pools are seasonal in nature and may dry up during some part of the growing season. During the dry season, these depressions may have a floor of matted and dark-stained leaves, and sometimes waterline marks can be seen on the surrounding trees. Some are semi-permanent; although they do not dry out completely, as summer progresses the pools are deficient in oxygen and nutrients.

These pools are very important breeding and hibernating sites for forest amphibians. Because these temporary pools do not support fish populations, they provide excellent amphibian habitat that allows for amphibian eggs and juveniles to develop without the threat of fish predation.

A number of amphibian species depend on vernal pools for all or portions of their life cycle. These species include the wood frog, spotted salamander and blue-spotted salamander. Other species, such as the spring peeper, pickerel frog and the red-spotted newt, use vernal pools for all or portions of their life cycle but are able to successfully complete their life cycles in other water bodies as well.Swamp deciduous Silver Maple by Sam BrinkerWEBVernal Pool, Sam Brinker

Research in Algonquin Park has shown that large pools are generally more valuable habitat than smaller ones. This is because they tend to retain water longer, which supports a greater diversity and abundance of amphibians. A pool with a surface area greater than 200 m2 will generally remain around for at least two months, and this is long enough to be considered valuable to wildlife.

It is very important to protect these features from activities that could degrade the integrity of the site. For example, keep roads, skid trails and ATVs out of these areas, maintain adequate canopy closure (shade) over these sites and do not undertake heavy cutting in or adjacent to these features.

Seasonally FloodedSwamp landscape by Regina VarrinWEBSeasonally Flooded Swamp, Regina VarrinWetlands provide a number of important functions in a watershed. They improve water quality by filtering sediments, nutrients and chemicals in runoff from cities, towns, roads, agriculture, mining and forestry operations. They can reduce flooding by holding back peak water flows when water levels are high, storing water within the wetland. This results in a more gradual release of water over a longer period of time, which can protect downstream property owners from flood damage. Having wetland vegetation along the shoreline of rivers, streams and lakes reduces erosion by trapping soils in their roots, helping to stabilize shorelines by dampening wave action and slowing water currents. Wetlands also play a role in groundwater discharge/recharge at different times during the year.

Wetlands provide food, shelter, breeding and resting places for an incredible number of species of plants, mammals, bird, reptiles, amphibians, fish and invertebrates. They provide the critical habitat that many such organisms need to survive. In Ontario, wetlands provide habitat for at least 47 plant and animal species that are identified as “at risk.”

dead treed swamp by Regina Varrin WEBDead Treed Swamp, Regina VarrinWetlands produce a number of valuable plants and animals, which can be harvested on a sustainable basis to provide an economic return. Such products include: trees (for lumber, pulp, fencing and firewood), wild rice, cranberries and blueberries, fish and commercial baitfish, bullfrogs and snapping turtles, waterfowl, furbearers (e.g., beaver, muskrat, mink), and natural medicines. These products can be harvested from wetlands in a sustainable, ecologically conscious manner, avoiding deterioration of the wetland.

These habitats are also popular places for non-consumptive recreation such as photography, bird watching, canoeing, hiking, snowshoeing, relaxation and spiritual or cultural experiences. Some wetlands have interpretive facilities, boardwalks and viewing towers where people can go to observe wildlife and learn about nature. Such facilities attract people to the wetlands and provide an economic return to local communities and the tourism industry.

It is estimated that Ontario has over 34 million hectares of wetlands; that’s about one-third of the province. Most wetlands are located in northern Ontario in areas that can only be remotely accessed by people. The majority of Ontario’s human population resides in southern Ontario, and this settlement pattern has been a major factor contributing to wetland loss in the province.Marsh1 by Darryl MitchellWEBMarsh, Darryl Mitchell

Wetlands are continually under stress from both naturally occurring phenomena and human disturbances. Some stress is beneficial for wetlands. For example, fluctuating water levels can lead to increased diversity of plant communities. Other stresses may harm wetland functions and values. These include direct stresses, such as draining and filling, which originate in the wetland itself, and indirect stresses like agricultural run-off and acid rain that are usually physically removed from the wetland.

The major threats to wetlands include drainage for agriculture, development and road construction. Other stressors include large water-takings, contaminated runoff and invasive species. Dredging, urban and cottage development, and peat extraction also threaten wetlands.

Invasive species are a growing environmental and economic threat to Ontario. Invasive species are harmful alien species whose introduction or spread threatens the environment, the economy or society, including human health. Once established, invasive species are extremely difficult and costly to control and eradicate, and their ecological effects are often irreversible.

Private woodlot owners can do their part to slow the spread of invasive species through a number of actions. You can learn to identify invasive plants that threaten woodland swamps and report them through Ontario’s Early Detection and Distribution Mapping System (EDDMapS Ontario) . You can also visit the Invading Species Awareness Program’s website  to get more information and browse resources such as factsheets and best management practices for invasive species that threaten woodlots. Another useful resource is The Landowner’s Guide to Controlling Invasive Woodland Plants

Working in or around swamps and other wetlands requires careful consideration of your activities and how they may affect these sensitive habitats. This is because working within, or adjacent to, wetlands can affect the diversity of plant and animal life, the structure of the vegetation, and/or the ability of the wetland to function naturally, including important physical and chemical properties.

Some good practices include:
  • maintaining the natural features of the wetland as much as possible, including living and non-living components;
  • minimizing the risk of adding sediment to the site, when cutting trees on adjacent slopes, through erosion control such as sediment fencing, bio logs and non-invasive annual cover crops;
  • restricting work in swamps to the drier seasons to avoid rutting of the soil, which can negatively affect the way that water is stored and moves in the wetland;
  • minimizing disturbance of amphibian breeding activity in woodland pools; and,
  • limiting changes to

There are a number of grant and incentive programs available to landowners who are interested in increasing the conservation value of their property.

The Conservation Land Tax Incentive Program (CLTIP) provides for a 100 percent property tax exemption on eligible conservation lands in return for landowner agreement not to undertake activities that will degrade, damage or remove the natural value of those lands.

Landowners may participate in both the CLTIP and Managed Forest Tax Incentive (MFTIP) programs, provided the eligible areas do not overlap and the property meets the eligible criteria and the requirements of each program on an ongoing basis. Through MFTIP, eligible lands are classified as managed forest and are taxed at 25 percent of the municipal tax rate set for residential properties.

Through the Land Stewardship and Habitat Restoration Program (LSHRP), you can get up to $20,000 in matching funds for a project that maintains or restores habitats that benefit fish, animals and/or plants.

Disclaimer

Information on this website may be accessed and downloaded, but please do not reproduce or duplicate without the consent of the OWA.

Member Login

eLetter