This ecozone is located at the southern end of Hudson Bay, and also encompasses the western and southeastern shores of James Bay. It exists mainly in Ontario, but spills over in the west into Manitoba, and in the east into a very small area of Quebec. Altogether, the zone covers approximately 300,000 square kilometres, an area almost

a third the size of British Columbia.

As its name implies, this is flat country. Virtually all the land is between sea level and 200 metres. The land tilts slightly, allowing the region’s rivers to drain slowly into the two huge bays. But drainage is very poor, making the ground sodden and spongy. Here, in fact, lie a quarter of the Earth’s wetlands, a wide belt of peat-producing bogs and fens, collectively called muskeg (an Algonquian term for “grassy bog”). Salt marshes and tidal flats fringe the coastline, the intersection of land and water barely defined as the water-logged earth meets the shallow sea.

A subarctic region, the Hudson Plains has short cool summers and severely cold winters. Mean annual winter temperatures range from -19°C at the western end, in Manitoba, to -16°C in the east, in Quebec. Mean summer temperatures, moderated by the immense presence of Hudson Bay, stay about the same throughout the zone, ranging between 10.5°C and 11.5°C. Precipitation is highest, at 800 millimetres, in