Central Canadian Shield forests
This ecoregion consists of rolling hills, lakes, bogs and rocky outcrops covering a large curved swathe on the Canadian Shield from eastern Manitoba and Northern Ontario running southeastwards through Thunder Bay District to the north shore of Lake Superior and then northeastwards into western Quebec. The area has a cool climate with summer temperatures averaging around 13°C dropping to a very cold -17°C in winter, with the hills around Lac Seul in northwestern Ontario being warmer and wetter than most of the area. Average rainfall in the eastern side of the ecoregion is 550mm per year, rising to 750mm in the centre (near Lake Nipigon for example), up to 900mm in the west. Specific areas include Lake Nipigon and Big Trout Lake (Ontario). These forest contrast with more severe boreal forest ecoregions such as the Eastern Canadian Shield taiga to the north, which covers most of Northern Quebec and Labrador.
Lake Ontario
Most of the forests around the lake are deciduous forests dominated by trees including maple, oak, beech, ash and basswood. These are classified as part of the Mixedwood Plains Ecozone by Environment Canada, or as the Eastern Great Lakes and Hudson Lowlands by the United States Environmental Protection Agency, or as the Great Lakes Ecoregion by The Nature Conservancy. Deforestation in the vicinity of the lake has had many negative impacts, including loss of forest birds, extinction of native salmon, and increased amounts of sediment flowing into the lake. In some areas more than 90 percent of the forest cover has been removed and replaced by agriculture. Certain tree species, such as hemlock, have also been particularly depleted by past logging activity. Guidelines for restoration stress the importance of maintaining and restoring forest cover, particularly along streams and wetlands.