EcoMAP (Ecological Mapping Analysis and Protocols) is a suite of geospatial data sets and analysis applications which has been developed by GeoInsight Corporation and A.M. Turner and Associates over the past three years with support from a number of government agencies. EcoMAP is built on the premise that by aggregating diverse data sets to a common geographic framework, spatial analysis can be used to derive and present complex ecological information. Such information is needed to guide the development of consistent policies and programs which are required for conservation and sustainable resource management. Parts of the EcoMAP database have also been used to present a national perspective of many ecological themes through the National Atlas of Canada. In order to provide continuity the EcoMAP name has been adopted for the National Atlas ecological module. The EcoATLAS layer uses the Ecological Framework of Canada as the common framework for data and analysis. Ecozones - First Level The most generalized level in the framework is the ecozone. The country was grouped according to very broad physiographic and ecological similarities into 15 ecozones. These have been described previously by Wiken (1986). Ecoprovinces - Second Level The next level in the ecological framework is the ecoprovince. The ecozones were subdivided into smaller units based on finer categories of physiographic similarities. There are 53 units at the terrestrial ecoprovince level. Ecoprovinces are a useful ecosystem intermediate scale for national and regional planning and reporting purposes. Ecoregions - Third Level The ecological framework is divided into a total of 194 ecoregions (217 areas). Each ecoregion has a name, which is normally based on a prominent biophysical or physiographic feature within the ecoregion. The elements used to guide the consistent formulation of national ecoregions were the published national maps on climate (Ecoregions Working Group 1989), physiography (Bostock 1970), and existing provincial ecological frameworks. Wherever available, more detailed provincial climate and physiographic information was used, as well as geologic and vegetation cover information. Consultation between federal and provincial/territorial authorities ensured that local perceptions of the landscape were incorporated into the ecoregion construction. Ecodistricts - Fourth Level A similar process was followed to further subdivide ecoregions into 1021 ecodistricts. Each ecodistrict is characterized by relatively homogeneous biophysical and climatic conditions. The differentiating characteristics of ecodistricts are: regional landform, local surface form, permafrost distribution, soil development, textural group, vegetation cover/land use classes, range of annual precipitation, and mean temperature. Ecodistrict size is a function of regional variability of these defining attributes, and minimum size is approximately 100,000 ha. Ecodistricts are designed for use at a map scale of 1:1 million to 1:2 million. For free download from GeoGratis the ecodistrict framework has been tagged with a number of attributes to be used for display or analysis. The following table describes these attributes and the field names under which they are found in the database that accompanies the GIS file. Note that the ecodistricts are numbered from 1 to 1031. Of these ten are considered to be empty polygons because they are totally within bodies of water i.e. Great Slave Lake. These ten ecodistricts are 172, 240, 330, 673, 719, 721, 722, 725, 842 and 845. There are also a number of very small polygons with a class number of (0) which represent water areas