Through the Ontario Geospatial Data Exchange (OGDE),3 Gartner Lee and Neptis were able to obtain the digital NRVIS (Natural Resource Values Information System) data from the Ontario Ministry of Natural Resources' Land Information Ontario (LIO) warehouse for the entire study area. NRVIS is the most recent and most comprehensive land database for southern Ontario. When the data were acquired in 2002, there were 712 "layers" of land information in the system. The layers of most relevance to this study were:
- Wooded areas. Derived from aerial photo-interpretation, primarily during the 1980s, wooded areas represent contiguous areas of forested land. Because of the expansion of urban areas, some of the wooded areas derived from the land database no longer exist. Reforestation efforts in other areas have created new wooded areas. Overall, however, this data layer represents the most up-to-date representation of forests in South-central Ontario.
- Water features. These include permanent and intermittent streams, lakes, ponds and "cartographic wetlands." Cartographic wetlands are determined through aerial photo-interpretation, and often are located in the same area as evaluated wetlands. These wetlands may have been formally evaluated by the OMNR; however, the spatial limits of these features rarely coincide with the mapped boundaries of evaluated wetlands. These discrepancies are often due to differences in the scale, date, and quality of the aerial photography used, as well as the protocol of the Province's Ontario Wetland Evaluation System (OWES), which identifies wetlands primarily on the basis of vegetation rather than topography or hydrology. The "cartographic wetland" layer includes many more wetlands (albeit generally the smaller ones) than have been evaluated by the Ministry of Natural Resources and some Conservation Authorities, particularly in the outer parts of the study area (e.g., northern Simcoe and Peterborough counties and the City of Kawartha Lakes).
- Evaluated wetlands. These wetland features have been visited and ranked by experts in wetland evaluation using the Ontario Wetland Evaluation System (OMNR 1993), which categorizes wetlands into varying levels of significance. Those with higher scores are considered provincially significant, while those with lower scores are not considered provincially significant.
- ANSIs (Areas of Natural or Scientific Interest). OMNR (1987) designates ANSIs as areas "of land and water containing natural landscapes or features which have been identified as having values related to protection, natural heritage appreciation, scientific study or education. Where ANSIs occur on public lands managed by the Ministry, it will ensure that the land uses and activities which occur provide for the protection of the identified values. On private lands, the Ministry will, through cooperation with others, attempt to ensure that landowners are aware of significant features on their properties and seek the owner's cooperation in protecting such features." ANSIs can be either Life Science or Earth Science areas and are classified as being Provincially Significant or Regionally Significant.
- ESAs (Environmentally Sensitive/Significant Areas). Municipalities, often in cooperation with the local Conservation Authority, may designate ESAs (sometimes referred to in Official Plans as Environmentally Sensitive Policy Areas). Because they are designated locally, different criteria are used from jurisdiction to jurisdiction. Not all upper-tier municipalities in the study area use this designation.
- Provincial Parks. Provincial Park boundaries are defined by the Ministry of Natural Resources.
- Conservation Areas. These are lands owned and managed by local Conservation Authorities. Most are natural to semi-natural areas, with limited development in the form of access roads, picnicking areas, trails, interpretive facilities, etc.
- Crown Land. This is provincially owned land, administered by the Ontario Ministry of Natural Resources, which may be managed for resources or as natural recreation areas. Crown Land is significant only in the northern part of the study area (e.g., the County of Simcoe, the County of Peterborough, and the City of Kawartha Lakes).
- Oak Ridges Moraine Land Use. The Oak Ridges Moraine Conservation Plan (ORMCP) has a significant impact on the status and distribution of Greenlands in the study area.
- Niagara Escarpment Plan. The Niagara Escarpment Plan (NEP) includes land use designations and policies administered by the Niagara Escarpment Commission.