This data was produced in 1999 by rationalizing a 48-class database into 28 distinct classes. The original database was derived from digital, multispectral Landsat Thematic Mapper data recorded between 1986 and 1997, with most of the satellite data frames recorded in the early 1990s. The resulting database includes: * vegetation types such as forests, wetlands and pasture * categories of non-vegetated surface such as waterbodies, bedrock or settlements The data reflects the nature of the land surface rather than the land use.

The Ministry of Natural Resources defines ecological units on the basis of bedrock, climate (temperature, precipitation), physiography(soils, slope, aspect) and corresponding vegetation. This enhances their compatibility with national and continental classification systems. The ELC of Ontario is used for descriptive, planning, and resource management purposes. The upper levels in its hierarchy may be relevant for provincial and municipal land-use planning initiatives. The lower (finer-scale) levels of the hierarchy are most useful for detailed resource management prescriptions and other local and site planning applications. This packaged dataset is classified into 3 hierarchical categories: * Ecozone: used for national and coarse-scale provincial reporting such as analyses of climate, demographics and watersheds * Ecoregion: used for determining the significance or status of wetland classes and certain other natural heritage features (e.g., old growth forest), setting targets for Wilderness Class Provincial parks, State of the Forest reporting and studying natural disturbance regimes * Ecodistrict used for assessing biodiversity levels, defining seed zones, mapping ecosystem types and setting targets for the identification of natural heritage systems [Introduction to ecological land classification](https://www.ontario.ca/page/introduction- ecological-land-classification-systems) *[ELC]: Ecological land classification

This dataset shows the boundaries of systems of natural heritage features and areas, lands and waters that support connectivity and have significant ecological value. It includes areas defined in provincial plans such as the: * [Greenbelt Plan](https://www.ontario.ca/document/greenbelt-plan-2017) * [Oak Ridges Moraine Conservation Plan](https://www.ontario.ca/page/oak-ridges-moraine-conservation-plan-2017) * [Niagara Escarpment Plan](https://www.escarpment.org/LandPlanning/NEP) * [Growth Plan for the Greater Golden Horseshoe](https://www.ontario.ca/document/place-grow-growth-plan-greater-golden-horseshoe) This dataset does not include modifications to systems made by municipal governments as part of their official plans.