Mer Bleue Bog is one of the largest bogs in southern Ontario and arguably the most important natural area in the Greenbelt. Ecologically, Mer Bleue is an especially valuable example of a northern ecosystem — more typical of the Arctic than the Ottawa Valley — and it has been designated an internationally significant wetland under the United Nations' Ramsar Convention.

The most striking feature of the area is the bog mat itself, a “sea” of deep, saturated peat overtopped by open heath and stunted to moderate-sized black spruce and tamarack trees.

The mat is home to a variety of plants, some of...