
Ontario can be subdivided into several different geographical areas based on forest science and ecology as well as administrative boundaries and land ownership.
These profiles include:
There are four major forest regions present in Ontario:
Each forest region is characterized by its climate, forest ecosystems and wildlife species. North-south gradients in temperature and east-west gradients in precipitation largely determine the extent of these forest regions. Most of Ontario’s population lives within the Great Lakes-St. Lawrence and Deciduous forest regions.
Broad zones of natural transition occur between forest regions. As a result, certain tree species may appear in what seem to be inappropriate forest regions, for example, the occurrence of maple or white pine in the southern reaches of the Boreal forest. In some locations, the transition zone may be more than 100 kilometres wide. More about Ontario's forest regions..
Area of the Undertaking (AOU)
An area consisting of approximately 385,000 square kilometres (or 38.5 million hectares) of Crown land, on which forest management activities are conducted in Ontario, lying within the geographic boundaries of the Area of the Undertaking.
Map
Ontario is divided into three management zones for the purpose of forest management.
The Northern Boreal Forest describes the large expanse of boreal and Hudson Bay lowlands in the far north. No Crown forest management activity takes place in this largely inaccessible tract of wilderness. The Area of the Undertaking (AOU) refers to the middle zone where most forest management is currently practiced. Southern Ontario is the area south of the AOU where most of the population in the province lives.
Most of the land in Ontario is owned by the people of Ontario, in the form of Crown and Park land and water. Approximately 13% of the land in Ontario is held in other types of ownerships. These different ownership classes tend to be concentrated in southern and central Ontario, but they do exist through to the northern tip of the province. Ownership classes include:
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MNR Regions |
The Ontario Ministry of Natural Resources (MNR) currently has three main administrative regions, each with a regional office and many district offices.
Ecological Land Classification (ELC) systems have been used for over 50 years in Ontario. This hierarchical system is useful for describing, planning, and managing natural areas. The upper levels in Ontario’s ELC hierarchy are most useful for provincial and regional roll-ups of data and for strategic planning. The lower levels of the hierarchy are most useful for more detailed resource management purposes.
The system devised by Hills (1959) contained two higher-order categories, site regions and
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Ecological Land Class Regions
More details available in "Forest Resources of Ontario" report. |
In recent years, this system was revised to take account of new information and new technology, while maintaining Hills’ original concepts (Crins and Uhlig, 2000). The revised site regions are now termed ecoregions, and the revised site districts are now termed ecodistricts. This mapping was further revised in 2003.
Ontario’s three broad ecozones are subdivided into 14 ecoregions, which are further subdivided into 71 ecodistricts. More details about Ontario’s ecoregions can be found in the Forest Resources of Ontario 2006.

This site is maintained by the Government of Ontario