Glossary for Species & Ecosystems At Risk

Species occurring infrequently and unpredicatably, outside their usual range. Accidental species are excluded from the red, blue and yellow lists.

List of ecological communities, native species and subspecies in B.C. that are of special concern (formerly vulnerable).

Preservation, especially of the natural environment.

Cultivated populations are those plant populations that are being grown, attended, and/or propogated by humans outside of the species' natural habitat. They are also grown from plant material obtained from a "cultivated" source.

This term is used by the B.C. Conservation Data Centre and the NatureServe network.  In B.C. it incorporates plant associations from the Vegetation Classification of the Biogeoclimatic Ecosystem Classification, and other natural plant communities including both forested and non-forested ecosystems. Sources include ecosystem mapping projects, Ecological Reserves records, special inventory projects and other available literature.

A measure of the current ecological condition (structure, composition, and function) of an ecosystem as compared to reference ecosystems operating within the bounds of natural or historic ecological processes and disturbance regimes (Faber-Langendoen, et al 2012, Rocchio and Crawford 2011)

A dynamic complex of plant, animal, and microorganism communities, climatic factors and physiography, all influenced by natural disturbance events and interacting as a functional unit, and subject to large scale and localized small scale processes. Ecosystems vary enormously in size: a temporary pond in a tree hollow and an ocean basin are both ecosystems.

An extirpated, endangered or threatened ecosystem or an ecosystem of special concern (formerly called vulnerable).


A species or ecological community. The term "species" is used to include all entities at the taxonomic level of species, including interspecific hybrids, as well as all subspecies and plant varieties. Ecological communities are based primarily on Ministry of Forests and Range vegetation classification and the International Classification of Ecological Communities.

An area of land and/or water in which a species or ecological community is, or was present. An Element Occurrence (EO) should have practical conservation value for the Element as evidenced by potential continued (or historic) presence and/or regular recurrence at a given location. For species Elements, the EO often corresponds with the local population, but when appropriate may be a portion of a population (e.g., long distance dispersers) or a group of nearby populations (e.g., metapopulation). For ecological community Elements, the EO may represent a stand or patch of an ecological community, or a cluster of stands or patches of an ecological community.

“An assessment of the likelihood that if current conditions prevail, an occurrence will persist for a defined period of time, typically 10-100 years.  Element Occurrence ranks provide an assessment of the practical conservation value of an occurrence.” (NatureServe Element Occurrence Data Standard 2002). See also Viability and Ecological Integrity.

A record from the B.C. Conservation Data Centre containing information about an element occurrence, such as location, condition, and type of element occurrence.

Facing imminent extirpation or extinction.



Element Occurrence Record


Exotic species are non-native species that have become established and/or naturalized in BC as a result of human activity. Exotic species are also known as alien species, foreign species, introduced species, non-indigenous species and non-native species. Exotic species are excluded from the Red, Blue and Yellow lists.

Not all exotic species are invasive. Many simply occupy disturbed sites (e.g. roadsides), and don't displace native species. Invasive species are (usually) exotic species that have moved into natural ecosystems and have altered natural ecosystem characteristics.

The CDC also maintains a "Non-established" vascular plant list that includes non-native taxa (often garden escapes) that have been observed growing outside of cultivation, but that have not yet become established. Non-established taxa are grouped into the following categories: Ephemeral: Lasting for a season or rarely a bit longer, but do not persist. Occasional: Sometimes persisting, but not known to have spread beyond limited sites and usually found near plantings. To access the Non-established list, please visit the EFlora website


Still existing. Not extinct or extirpated.


Species that no longer exist.

Species and ecosystems that no longer exist in the wild in British Columbia, but may or do occur elsewhere.

Global conservation status rank for an element, as determined by NatureServe, based on information provided by Natural Heritage Programs and Conservation Data Centres.

Species and ecosystems at risk in British Columbia that have been designated by the Chief Forester (Ministry of Forests and Range) and Deputy Minister (Ministry of Environment) as requiring special management attention during forest and range operational planning or higher level planning.

This term has been replaced by NatureServe and its member programs with Ecological Community. A natural plant community is a naturally occurring unit of vegetation with relatively uniform species composition, physical structure and characteristic environmental requirements, within a designated geographical unit (location on the ground).

An organization dedicated to providing reliable information on species and ecological communities for use in conservation and land use planning. NatureServe is an independent nonprofit organization created in collaboration with the Network of Natural Heritage Programs and Conservation Data Centres and The Nature Conservancy (U.S.).

See Element Occurrence.

A recurring plant community with a characteristic range in species composition, specific diagnostic species, and a defined range in environmental requirements (site and soil characteristics, hydrology, localized climate, etc), and physical appearance or structure.

An extirpated, endangered or threatened species or a species of special concern (formerly called vulnerable).

Particularly sensitive to human activities or natural events but not endangered or threatened (as used by COSEWIC - A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats). Special concern was formerly referred to as "Vulnerable."

The Nature Conservancy (TNC) is a private, international conservation group whose mission is to preserve plants, animals and natural communities that represent the diversity of life on earth by protecting the lands and waters they need to survive. TNC used to oversee the Natural Heritage Network, but that duty has been taken over by NatureServe.

Likely to become endangered if limiting factors are not reversed.

Tracking means to be actively mapping known locations of species and/or ecological communities. The Conservation Data Centre tracks Red- and Blue-listed elements, and also some Yellow-listed taxa that are vulnerable during times of seasonal concentration (e.g., breeding colonies).

The probability of persistence of a species population, its health, reproduction, abundance, density and fluctuations, and the condition of the surrounding landscape as it affects the population. 

Particularly sensitive to human activities or natural events (as used by NatureServe - Vulnerable due to a restricted range, relatively few populations, recent and widespread declines, or other factors making it vulnerable to extirpation).