Mapping Methods

The B.C. Conservation Data Centre (CDC) follows NatureServe mapping methodology. Element occurrences (species and ecosystem) are represented as map polygons. An element occurrence may also reflect the uncertainty about the mapped location of the element occurrence, which can come from:

  • Imprecise data collection (e.g. inaccurate or older GPS devices)
  • Vague location descriptions

Element occurrences based on newer data are generally more precise. Often historic and older mapped element occurrences appear as large polygons due to greater uncertainty. The CDC is working on reducing these larger polygons to define areas that better represent the location of an element occurrence.

What Does "Element Occurrence" Mean?

An element occurrence can be any area of land or water where a species or ecosystem is found. Each element occurrence is evaluated on the probability of persistence of the element at a particular location. Based on this, each occurrence is assigned an element occurrence rank.

Standards for Mapping

Organization Standard
NatureServe Element Occurrence Data Standard
Core Methodology
Ministry of Environment

Terrestrial Ecosystems - Ecology