Restoring nature’s kidneys
Corn earworm moth on great lobelia, Southern Norfolk Sand Plain, ON (Photo by Mhairi McFarlane)
Wetlands are among the most productive and important ecosystems on Earth. They provide habitat for wildlife, act as nurseries for fish, reduce flooding and clean our water. They are also places of great beauty and enjoyment. Over the last century, many wetlands across Ontario have been lost due to human activity.
In 2012, the Nature Conservancy of Canada (NCC) embarked on a mission to restore wetland habitat in the lower reaches of the Big Creek watershed, located in NCC’s Southern Norfolk Sand Plain Natural Area in Norfolk County. In the 1800s, wetlands made up 30 per cent of the Haldimand-Norfolk County landscape, which encompasses Big Creek. By 2002, this number had dropped to less than six per cent.
The Big Creek watershed is located upstream of the Long Point Wetland Complex, an internationally recognized wetland under the Ramsar Convention and a globally Important Bird Area.
Over the last year, NCC and local contractors have worked hard to complete 94 hectares (232 acres) of restoration, including 18 hecatres (45 acres) of newly created wetlands in the lower reaches of the Big Creek watershed. By recreating some of these lost wetlands, NCC’s restoration work is improving connectivity between wetlands, creating more habitat for native plants and animals and restoring natural hydrology. These restored wetlands are important to the health of the local watershed. They mitigate floods by absorbing and holding water like a giant sponge and improve drinking water quality by filtering nutrients, and removing sediment and even bacteria.
The lands NCC often focuses on for wetland creation have a history of being wet in the spring and fall, creating challenges for planting and harvesting crops. These less-than-ideal conditions for farming provide fantastic opportunities for wetland restoration. NCC staff use historical images, field observations and conversations with landowners to identify wet areas and historical wetland features on our properties.
Once an area has been selected for restoration, NCC stewardship staff mark out the boundaries of the wetland, targeting low-lying or existing wet areas that will hold water. With input from former landowners, drainage superintendents and tenant farmers, areas where perforated pipes have been used to drain excess water from fields (also known as drainage tiles) are identified. We then bring in contractors that operate heavy equipment, such as backhoes and excavators, to dig out naturally low areas and excavate tiles to stop them from removing water. The wetlands then fill naturally with rainwater and runoff. To create more features that attract wildlife, we place large logs in and around the wetland for turtle basking sites, bat boxes and bird boxes to encourage nesting of species such as tree swallows.
The next step in the restoration process is the planting of native trees, flowers and grasses in areas surrounding the wetlands. The incredible amount of diversity in Norfolk County, part of the Carolinian zone, means that one restored site can have up 100 different species of plants seeded into it. Planting occurs through a combination of tools, including mechanical seeding, scattering seed by hand and hand planting of tree seedlings — often with the help of dedicated Conservation Volunteers.
Regular monitoring occurs to see what species are growing, what animals are using the wetlands and to identify any invasive species early so that we can manage them. This past year, almost immediately after equipment left the site, we observed snapping turtles, frogs and toads, waterfowl and shorebirds using the created wetlands. It truly shows that if you build it, they will come.