Definitions of NatureServe Conservation Status Ranks

Note that the term occurrences in these definitions refers specifically to Element Occurrences. Also, where no distinction is made, a definition is identical for species and ecological communities.

NatureServe Global Conservation Status Definitions

Listed below are definitions for interpreting NatureServe’s global (range-wide) conservation status ranks. Global conservation status ranks are assigned by NatureServe scientists or by a designated lead office in the NatureServe network.

Global (G) Conservation Status Ranks

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1 Possibly Eliminated ecological communities and systems may include ones presumed eliminated throughout their range, with no or virtually no likelihood of rediscovery, but with the potential for restoration, for example, American Chestnut (Forest).

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Variant Global Conservation Status Ranks

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2 A global conservation status rank may be not applicable for several reasons, related to its relevance as a conservation target. In such cases, typically the ecosystem is non-native, for example, ruderal vegetation, a plantation, agricultural field, or developed vegetation (lawns, gardens etc).

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Global Rank Qualifiers

RANK DEFINITION
? Inexact Numeric Rank - Denotes inexact numeric rank; this should not be used with any of the Variant Global Conservation Status Ranks or GX or GH.
Q Questionable taxonomy that may reduce conservation priority - Distinctiveness of the entity as an ecosystem type at the current level is questionable; resolution of this uncertainty may result in inclusion of the type in another type, with the resulting type having a lower priority (numerically higher) Conservation Status Rank. The "Q" modifier is only used at the global level and not at national or subnational levels.

For more detail, see Conservation Status Rank Qualifiers.

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NatureServe National and Subnational Conservation Status Definitions

Listed below are definitions for interpreting NatureServe conservation status ranks at the national (N-rank) and subnational (S-rank) levels. The term "subnational" refers to state or province-level jurisdictions (e.g., California, Ontario).

Assigning national and subnational conservation status ranks for species and ecosystems (ecological communities and systems) follows the same general principles as used in assigning global status ranks. Historically, a subnational rank, however, could not imply that a species or ecosystem is more secure at the state/province level than it is nationally or globally (e.g., a rank of G1S3 is invalid), and similarly, a national rank could not exceed the global rank. But this rule is under review, because current methods provide a more explicit role for Threats and Trends, which may indicate low levels of risk at national/subnational scales as compared to global scales. Subnational ranks are assigned and maintained by state or provincial NatureServe network programs.

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National (N) and Subnational (S) Conservation Status Ranks

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Variant National and Subnational Conservation Status Ranks

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Note: When the Element Global Rank is GNA, the Element National Rank should be entered as NNA and Element Subnation Rank should be entered as SNA for all national and subnational records associated with it. The ranks of NNA and SNA are also assigned when the Current Presence/Absence values for these records is Absent or Unknown/Undetermined.

3 A conservation status rank is not applicable for community Elements that are without conservation value, such as types that are considered Ruderal, Cultural, Invasive, and/or Modified/Managed.

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National and Subnational Rank Qualifiers

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For more detail, see Conservation Status Rank Qualifiers.

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See also:

Conservation Status Rank Qualifiers

NatureServe Conservation Status Assessments: Factors for Evaluating Species and Ecosystem Risk

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