Mer Bleue 2011: Walk in the Woods
- Category: News & Events
Summary of Walk-in-the-Woods Event
September 18, 2011, Mer Bleue Bog, Ottawa
On Sunday, September 18, the Ottawa Forests and Greenspace Advisory Committee (OFGAC) managed to squeeze in a summer walk a few days before the calendar said fall. And while the leaves were just beginning to turn and the past few evenings had a sharp briskness that hinted of chills to come, the weather for the walk was ideal. A bright blue cloudless sky, perfect 20 degree temperature and no wind greeted the large group of about 55 participants who gathered tostroll a boardwalk into Mer Bleue and learn the significance of this peat bog and the forest that bounds it.
At the shelter near the start of the boardwalk, OFGAC’s Chair, Nicole Parent, greeted everyone and introduced the two guest speakers for the day.
The first speaker, Dr. Elyn Humphreys, a geographer from Carleton University, is a specialist in bog ecology and dynamics. She introduced the participants to Mer Bleue’s wetland environment, describing what defines a bog and why this particular one is so special. Dr. Humphreys explained how peat forms and how long that process takes. Mer Bleue is rare, in that it has up to 6m of peat in parts of the bog, which was created over thousands of years. Normally a fen or bog would have about 40cm depth of peat. Participants learned that a bog is rain-fed only, and therefore often quite dry, whereas, a fen is fed by a flow of water, such as a river or creek, or from groundwater, such as springs, and has more standing and flowing water. She also highlighted the peat bog’s complicated role as a carbon sink - sequestering carbon while releasing methane because vegetation is decomposing in wet soil. Unfortunately, in the south of Canada especially, we are losing our important bogs and peatlands through draining.
The second guest speaker, Mr. James McCuaig, a geographer and urban planner, provided us with historical background on Mer Bleue and its status as a Ramsar designated wetland. The Ramsar Convention (named for the city in Iran where it was launched in 1971) is an intergovernmental treaty whose member countries commit to maintaining the ecological character of their Wetlands of International Importance and to plan for the "wise use", or sustainable use, of all of the wetlands in their territories.
Today there are 160 signatories to the Convention and 1,951 sites designated as Wetlands of International Importance, including 37 in Canada, that are protected. Mr. McCuaig explained to participants that the Convention’s mission includes providing reasonable access to the public for enjoyment and learning opportunities about wetlands (see link http://www.ramsar.org/cd/en/ramsar-home/main/ramsar/1_4000_0__ )
Both speakers answered a number of questions from participants, and then everyone headed out to experience the essence of Mer Bleue for themselves, following the boardwalk through the typical bog habitat. Periodically, along the trail, the NCC has erected educational panels that explain different aspects of the bog’s ecology, which were very helpful.
In the bog itself, tall clusters of cotton grass waved in the breeze amongst shrubs of leatherleaf and Labrador tea. The trees growing in the bog’s ecosystems are mainly individual black spruce and tamarack (larch), with some scattered birches, maples and alders (see link to NCC Mer Bleue page -- http://www.canadascapital.gc.ca/bins/ncc_web_content_page.asp?cid=16297-16299-9735-113846-9743&lang=1&bhcp=1 )
Around the perimeter of the bog there are more densely forested areas. There are some open water channels, as well, and near the end of the boardwalk, at the head of one of these channels, is a large, and now abandoned, beaver lodge. Close by, the trail climbs out of the bog into a forested area and here we saw evidence of beavers having felled several large poplar trees, as well as trees with partially gnawed trunks (see attached photo). The NCC has had to protect many other large poplar trees by wrapping them in fencing to deter the beavers.
To finish off the event, the group reassembled at the starting point long enough to ask a few more questions of our guest speakers and to present them with small gifts from OFGAC for having provided their time and expertise.
mer bleue guided walking tour group photo set 1.pdf
mer bleue guided walking tour group photos set 2.pdf
Mer Bleue, designated as a United Nations Ramsar Site in 1995, covers an area of 3,447 ha. It is also recognized as a Provincially Significant Wetland (PSW) and an Area of Scientific Interest (ANSI) by the province.
Fifty percent of Mer Bleue is a raised boreal peat dome – a Sphagnum bog more commonly found in northern Canada. Finding this remnant ecosystem, originally created by the influences of the North American Ice Sheet and its successor, the Champlain Sea, between 8-15,000 years ago, so far to the south is what makes the bog special.
The borders of the bog have been transformed into pond and marsh by the North American Beaver (Castor Canadensis). Because of the excellent habitat and abundance of food, there is a large beaver population in Mer Bleue, especially along the Dolman Ridge which is one of the five ‘fingers’ of raised sandy soil jutting into the bog itself. Beavers prefer aspen and poplar as their food sources, but will also eat birch, maple, willow and alder. Cattails, water lilies, and other aquatic vegetation round out their diet. Mer Bleue is a veritable cornucopia for them!
Turtles are also present in Mer Bleue -- rare Spotted Turtles are found here, along with other, more common species, such as the Painted Turtle and the Snapping Turtle.