Conservation Data Centre Element Occurrences

The B.C. Conservation Data Centre (CDC) uses the NatureServe method to map known locations of species and ecological communities at risk, these are called Element Occurrences (an area of land and/or water where a species or ecosystem is known to have been).  The CDC database is updated on a regular basis.

• An element occurrence record (EO) can consist of one or more source features (i.e. observations)  For species, an element occurrence is generally equivalent to a population.
• An element occurrence has conservation significance and is relevant in land management decisions.
• An element occurrence is not an observation. It is a value-added product that includes assessment of observations for conservation significance, and includes verification of the information source.
• All element occurrences are polygons: the size of the polygon usually reflects the locational uncertainty associated with the source data, represented with varying sized circles. Some polygons may be larger to reflect the actual area covered by the element occurrence.

If you do not find an element occurrence in your area of interest, this means there are none currently mapped in the CDC database. The best way to verify whether an area contains a species or ecosystem at risk is to do a detailed assessment of the property during the appropriate season.

Learn about the ways you can access mapped element occurrences and potential locations of species and ecosystems at risk:

• Mapped locations

Element Occurrence Layers

CDC publicly available element occurrences of species and ecosystems are in layers.

• Publicly Available Occurrences: Element occurrences of species and ecosystems at risk that are publicly available. The majority of CDC data is displayed in this layer.
• (Historical) Publicly Available Occurrences: Element occurrences are deemed historical if the last observation was greater than 40 years ago or the element occurrence is considered to be possibly extirpated
• (Masked Secured) Publicly Available Occurrences: A public view of those element occurrences that are secured – these appear as large “fuzzed” polygons that hide the actual location of the element occurrence and contain no associated information

Secure Element Occurrence Data

A small number of mapped element occurrences are withheld from public, as set out in the Species and Ecosystems Data and Information Security Policy. The most common reasons that an element occurrence would be secured are:

• The species or ecosystem data is considered to be susceptible to persecution or harm if the data is publicly available
• The data is proprietary

Some of the details of these element occurrences may be released on a need-to-know basis.

• Find out how to request secured element occurrence details
• Learn about data that's considered to be susceptible to persecution or harm (PDF)
• See how to cite CDC as a data source