The Hudson plains are in parts of Ontario and Manitoba. Their area is about 350 000 km squared. The west edge of the Hudson Plains is around Churchill in north Manitoba, the eastern edge is around Fort Rupert, the northern edge borders Hudson Bay and James Bay and the southern edge is near Kapuskasing, Manitoba. Moosonee and Churchill are major cities in the Hudson Plains area, and lesser known cities include Attawapiskat, Fort George, Eastmain, Fort Albany, Lake River, Winisk, Fort Severn, and Shamattawa.
Vegetation in the Hudson Plains mostly follows latitude patterns, because of the flat nature of the land. The Hudson Plains are a merge of boreal forest and tundra. Trees are few and far between, denser in the southern, wetter area of the ecozone. In this wetter area, the variety of plants includes: tussocks of sedge, cottongrass, sphagnum moss, dwarf birch, willow shrubs, white spruce, black spruce, larch, balsam, poplar, tamarack, and Jack Pine. In the drier area, vegetation is shrubby and low-lying. It includes Lapland rosebay, crowberry, blueberry, cloudberry, reindeer moss, caribou lichen, and herbs such as arctic aven, purple saxifrage, prickly saxifrage, and lousewort.
The average elevation in the Hudson Plains is 120m above sea level. It is a flat lowland area. The land is made up of mineral soils, with few outcrops of underlying sandstone and shale. This land was created when the weight of glaciers depressed the Hudson Bay region and the ocean waters flooded areas up to 300 km inland from the current coastline. Then, during the retreat of the huge continental ice sheets, drainage into the Hudson Bay was blocked and lakes (Agassiz and Ojibway for example) were formed along the margins of the retreating ice. Since glaciation, flat terrain, mineral soil, and poor drainage have promoted the development of wetlands in the area.
The major rivers in the Hudson Plains are the Nelson and the Hayes in Manitoba. Rivers in the area follow long, straight routes. The flow of the rivers varies dramatically throughout the year and is virtually non existent from September to January. In the summer, channels contain pools and stretches of trapped water.
The Hudson Bay moderates the temperature of the lowlands during the summer, but not during the winter, because it ices over. Thus, in the winter, the region has cold, dry, arctic air.
The temperature is colder near the coast and warmer inland. Average temperatures in July are about 12 to 16∘,C, and average temperatures in January are about -25 to -23∘,C. Each year, there are about 500-1000 growing degree days (above 5∘,C). The average annual precipitation is 500-700 mm, peaking in July.
Mineral soils cover the Hudson Plains area. These soils are mainly made up of finely textured clay deposited by marine and glacial process. There are few outcrops of...