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Conservation Status Ranks
State and Global Ranks
This ranking system facilitates a quick assessment of a species’ or habitat type’s rarity and is the primary tool used to develop conservation, protection, and restoration priorities for individual species and natural habitat types. Each species or habitat is assigned both a state (S) and global (G) rank on a scale of critically imperiled (1) to secure (5). Factors such as range extent, the number of occurrences, intensity of threats, etc., contribute to the assignment of state and global ranks. The definitions for state and global ranks are comparable but applied at different geographic scales; something that is state imperiled may be globally secure.
The information supporting these ranks is developed and maintained by the Maine Natural Areas Program (state ranks) and NatureServe (global ranks). For More Information, please visit NatureServe Explorer's Statuses page.
| Rank | Definition |
|---|---|
| G1 | Globally Critically Imperiled – At very high risk of extinction (species) or collapse (ecosystem) due to very restricted range, very few populations or occurrences, very steep declines, very severe threats, or other factors. |
| G2 | Globally Imperiled – At high risk of extinction (species) or collapse (ecosystem) due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors. |
| G3 | Vulnerable Globally – At moderate risk of extinction (species) or collapse (ecosystem) due to a fairly restricted range, relatively few populations or occurrences, recent and widespread declines, threats, or other factors. |
| G4 | Apparently Secure Globally – At fairly low risk of extinction (species) or collapse (ecosystem) due to an extensive range and/or many populations or occurrences, but with possible cause for some concern as a result of local recent declines, threats, or other factors. |
| G5 | Secure Globally – At very low risk or extinction (species) or collapse (ecosystem) due to a very extensive range, abundant populations or occurrences, and little to no concern from declines or threats. |
| GX | Presumed Extinct/Collapsed Globally – Presumed Extinct (species) - Not located despite intensive searches and virtually no likelihood of rediscovery. Presumed Collapsed (ecosystem) - Collapsed throughout range, due to loss of key dominant and characteristic taxa and/or elimination of the sites and ecological processes on which the type depends. |
| GH | Possibly Extinct/Collapsed Globally – Possibly Extinct (species) or Possibly Collapsed (ecosystem) - Known from only historical occurrences but still some hope of rediscovery. Examples of evidence include (1) that a species has not been documented in approximately 20-40 years in human-dominated landscapes despite some searching and/or some evidence of significant habitat loss or degradation; (2) that a species or ecosystem has been searched for unsuccessfully, but not thoroughly enough to presume that it is extinct or collapsed throughout its range. |
| S#S# / G#G# | Range Rank – A numeric range rank (e.g., S2S3 or S1S3) is used to indicate any range of uncertainty about the status of the species or ecosystem. |
| SU / GU | Unrankable – Currently unrankable due to lack of information or due to substantially conflicting information about status or trends. |
| SNR / GNR | Unranked – lobal or subnational conservation status not yet assessed |
| SNA / GNA | Not Applicable – A conservation status rank is not applicable because the species or ecosystem is not a suitable target for conservation activities (e.g., non-native species or ecosystems. |
| S1 | Critically Imperiled in Maine – At very high risk of extirpation in the jurisdiction due to very restricted range, very few populations or occurrences, very steep declines, severe threats, or other factors. |
| S2 | Imperiled in Maine – At high risk of extirpation in the jurisdiction due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors. |
| S3 | Vulnerable in Maine – At moderate risk of extirpation in the jurisdiction due to a fairly restricted range, relatively few populations or occurrences, recent and widespread declines, threats, or other factors. |
| S4 | Apparently Secure in Maine – At a fairly low risk of extirpation in the jurisdiction due to an extensive range and/or many populations or occurrences, but with possible cause for some concern as a result of local recent declines, threats, or other factors. |
| S5 / G5 | Secure in Maine – At very low or no risk of extirpation in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. |
| SX | Presumed Extirpated in Maine – Species or ecosystem is believed to be extirpated from the jurisdiction (i.e., nation, or state/province). Not located despite intensive searches of historical sites and other appropriate habitat, and virtually no likelihood that it will be rediscovered. |
| SH | Possibly Extirpated in Maine – Known from only historical records but still some hope of rediscovery. There is evidence that the species or ecosystem may no longer be present in the jurisdiction, but not enough to state this with certainty. Examples of such evidence include (1) that a species has not been documented in approximately 20-40 years in human-dominated landscapes despite some searching and/or some evidence of significant habitat loss or degradation; (2) that a species or ecosystem has been searched for unsuccessfully, but not thoroughly enough to presume that it is no longer present in the jurisdiction. |
| Qualifier | Definition |
|---|---|
| S#? / G#? | Inexact Numberic Rank – Denotes inexact numeric rank. |
| Q | Questionable taxonomy that may reduce conservation priority – Distinctiveness of this entity as a taxon or ecosystem type at the current level is questionable. The "Q" modifier is only used at the global level. |
| T# | Infraspecific Taxon (trinomial) – The status of infraspecific taxa (subspecies or varieties) are indicated by a "T-rank" following the species' global rank. |
State Legal Status
State legal status is defined according to Title 12 Section 544, and Title 12 Section 544 B which mandate the Department of Agriculture, Conservation and Forestry to produce and biennially update the official list of Maine's Endangered and Threatened plants. Periodic changes to the list are recommended to the Department by a technical advisory committee of botanists who use the most recent population data as per the Maine Natural Area Program's database, along with other relevant research and taxonomic information to recommend status changes.
- E–Endangered: Rare and in danger of being lost from the state in the foreseeable future; or federally listed as Endangered.
- T–Threatened: Rare and, with further decline, could become endangered; or federally listed as Threatened.
Non-Legal status
- SC–Special Concern: Rare in Maine, based on available information, but not sufficiently rare to be considered Threatened or Endangered.
- PE–Potentially Extirpated: Species has not been documented in Maine in past 20 years or loss of last known occurrence has been documented.