NatureServe conservation status

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Conservation status
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Lower Risk

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Comparison of Red list classes above
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The NatureServe conservation status system, maintained and presented by NatureServe in cooperation with the Natural Heritage Network, was developed in the United States in the 1980s by The Nature Conservancy (TNC) as a means for ranking or categorizing the relative imperilment of species of plants, animals, or other organisms, as well as natural ecological communities, on the global, national or subnational levels. These designations are also referred to as NatureServe ranks, NatureServe statuses, or Natural Heritage ranks. While the Nature Conservancy is no longer substantially involved in the maintenance of these ranks, the name TNC ranks is still sometimes encountered for them.


NatureServe ranks indicate the imperilment of species or ecological communities as natural occurrences, ignoring individuals or populations in captivity or cultivation, and also ignoring non-native occurrences established through human intervention beyond the species' natural range (as, for example, with many invasive species).

NatureServe ranks have been designated primarily for species and ecological communities in the United States and Canada, but the methodology is global, and has been used in some areas of Latin America and the Caribbean. The NatureServe Explorer website [1] presents a centralized set of global, national, and subnational NatureServe ranks developed by NatureServe or provided by cooperating U.S. Natural Heritage Programs and Canadian and other international Conservation Data Centers.


Most NatureServe ranks address the conservation status of a plant or animal species or a natural ecological community using a one-to-five numerical scale (from most vulnerable to most secure), applied either globally (world-wide or range-wide) or to the entity's status within a particular nation or a specified subnational unit within a nation. Letter-based notations are used for various special cases to which the numerical scale does not apply, as explained below. Ranks at various levels may be concatenated to combine geographical levels, and also to address infraspecific taxa (subspecies and plant varieties).

Global, national, and subnational levels

NatureServe conservation statuses may be applied at any or all of three geographical levels:

Commonly encountered ranks

The most commonly encountered NatureServe conservation statuses at the G-, N-, or S-level are:


  • 1Critically imperiled — (typically having 5 or fewer occurrences, or 1,000 or fewer individuals).
  • 2Imperiled — (typically having 6 to 20 occurrences, or 1,001 to 3,000 individuals).
  • 3Vulnerable — (rare; typically having 21 to 100 occurrences, or 3,001 to 10,000 individuals).
  • 4Apparently secure — (uncommon but not rare, but with some cause for long-term concern; typically having 101 or more occurrences, or 10,001 or more individuals).
  • 5Secure — (common, widespread, abundant, and lacking major threats or long-term concerns).


  • X - Presumed extinct or extirpated (not located despite extensive and intensive searches, with rediscovery not reasonably expected). Note that extinction is here considered a global (range-wide) phenomenon, while extirpation applies to loss within a particular national or subnational area, with the entity still extant elsewhere.
  • H - Possibly extinct or extirpated (of historical occurrence but not known recently extant, with some reasonable hope of rediscovery).
  • R or ? - Recorded within a nation or subnation, but local status not available or not yet determined. When combined with a global rank of G1 to G3, local status is 'Indeterminate,' but the entity is nevertheless presumed vulnerable, if still extant.

Thus, for example, a G3 species is "globally vulnerable", and an N2 species is "nationally imperiled" for the particular country the rank is assigned. Species with G, N, or S rankings of 4 or 5 are generally not the basis for major conservation actions.

Ranks for additional cases

Several less frequent special cases are addressed through other notation in the NatureServe ranking system, including:

Subspecies and plant varieties

Non-native (exotic) taxa

Note, however, that regionally native species or other taxa that have recently arrived in the area of interest by natural means (such as wind, floods, or birds), without direct or indirect human intervention, are ranked by the same methodology and notation as for other native taxa.

Interspecific hybrids

However, reproducing or other self-maintaining, population-forming species known or suspected to be of hybrid origin are ranked using the same methodology and notation as for other species. For example, many fertile polyploid species of ferns formed by interspecific hybridization followed by chromosome doubling. Some of these hybrid-derived species are quite rare (ranked G1), but others are so widespread, abundant, and secure as to deserve a G5 rank.

Taxa extant only in captivity or cultivation

Variant ranks

Combinations of ranks

Any NatureServe rank may be used alone, or G-, T-, N-, and S- ranks may be combined in that sequence, such as a G5N3S1 rank for a particular species (or ecological community) within a particular subnational unit of a particular nation. An entity has only a single global rank (G-rank alone, or G-rank and T-rank combination), but may have different N-ranks or S-ranks for different nations or subnations within its geographical range.

See also

Related Research Articles

Ecoregion Ecologically and geographically defined area that is smaller than a bioregion

An ecoregion or ecozone is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species. The biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. In theory, biodiversity or conservation ecoregions are relatively large areas of land or water where the probability of encountering different species and communities at any given point remains relatively constant, within an acceptable range of variation.

This is an index of conservation topics. It is an alphabetical index of articles relating to conservation biology and conservation of the natural environment.

Ex situ conservation literally means, "off-site conservation". It is the process of protecting an endangered species, variety or breed, of plant or animal outside its natural habitat; for example, by removing part of the population from a threatened habitat and placing it in a new location, an artificial environment which is similar to the natural habitat of the respective animal and within the care of humans, example are zoological parks and wildlife safaris. The degree to which humans control or modify the natural dynamics of the managed population varies widely, and this may include alteration of living environments, reproductive patterns, access to resources, and protection from predation and mortality. Ex situ management can occur within or outside a species' natural geographic range. Individuals maintained ex situ exist outside an ecological niche. This means that they are not under the same selection pressures as wild populations, and they may undergo artificial selection if maintained ex situ for multiple generations.

Botanical name Scientific name for a plant, alga or fungus

A botanical name is a formal scientific name conforming to the International Code of Nomenclature for algae, fungi, and plants (ICN) and, if it concerns a plant cultigen, the additional cultivar or Group epithets must conform to the International Code of Nomenclature for Cultivated Plants (ICNCP). The code of nomenclature covers "all organisms traditionally treated as algae, fungi, or plants, whether fossil or non-fossil, including blue-green algae (Cyanobacteria), chytrids, oomycetes, slime moulds and photosynthetic protists with their taxonomically related non-photosynthetic groups ."

Conservation status Indication of the chance of a species extinction, regardless of authority used

The conservation status of a group of organisms indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation status: not simply the number of individuals remaining, but the overall increase or decrease in the population over time, breeding success rates, and known threats. Various systems of conservation status exist and are in use at international, multi-country, national and local levels as well as for consumer use.

NatureServe Non-profit organization

NatureServe, Inc. is an Arlington, Virginia-based non-profit organization that provides proprietary wildlife conservation-related data, tools, and services to private and government clients, partner organizations, and the public. NatureServe reports being "headquartered in Arlington, Virginia, with regional offices in four U.S. locations and in Canada." In calendar year 2011 they reported having 86 employees, 6 volunteers, and 15 independent officers.

In botany, an infraspecific name is the scientific name for any taxon below the rank of species, i.e. an infraspecific taxon. The scientific names of botanical taxa are regulated by the International Code of Nomenclature for algae, fungi, and plants (ICN). This specifies a 'three part name' for infraspecific taxa, plus a 'connecting term' to indicate the rank of the name. An example of such a name is Astrophytum myriostigma subvar. glabrum, the name of a subvariety of the species Astrophytum myriostigma.

GRANK, or Global Rank is a ranking of the rarity of a species, and is a useful tool in determining conservation needs. Global Ranks are derived from a consensus of various conservation data centres, natural heritage programmes, scientific experts and NatureServe.

SRANK or Subnational Rank seeks to ascertain the rarity of species within subnational boundaries.

In botanical nomenclature, autonyms are automatically created names, as regulated by the International Code of Nomenclature for algae, fungi, and plants that are created for certain subdivisions of genera and species, those that include the type of the genus or species. An autonym might not be mentioned in the publication that creates it as a side-effect. Autonyms "repeat unaltered" the genus name or species epithet of the taxon being subdivided, and no other name for that same subdivision is validly published. For example, Rubus subgenus Eubatus is not validly published, and the subgenus is known as Rubus subgen. Rubus.

Critically Endangered IUCN conservation category

An IUCN Red List Critically Endangered (CR) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of 2020, there are 6,811 species that are considered to be Critically Endangered. This is out of the 120,372 species currently tracked by the IUCN.

Taxonomic rank Level in a taxonomic hierarchy

In biological classification, taxonomic rank is the relative level of a group of organisms in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, order, class, phylum, kingdom, domain, etc.

<i>Scutellaria ovata</i>

Scutellaria ovata, commonly known as the heartleaf skullcap, is a member of the mint family (Lamiaceae). Its range in the United States is from Minnesota to Florida, and from Texas to the Atlantic coast. It is also native to Mexico.

Measurement of biodiversity Ways to empirically assess biodiversity

Conservation biologists have designed a variety of objective means to measure biodiversity empirically. Each measure of biodiversity relates to a particular use of the data. For practical conservationists, measurements should include a quantification of values that are commonly shared among locally affected organisms, including humans. For others, a more economically defensible definition should allow the ensuring of continued possibilities for both adaptation and future use by humans, assuring environmental sustainability.

Interdunal wetland

An interdunal wetland, interdunal pond or dune slack is a water-filled depression between coastal sand dunes. It may be formed either by wind erosion or by dunal encroachment on an existing wetland. The wind erosion process involves wind scooping out sufficient sand to reach the water table, and typically occurs behind the first line of foredunes.

Lake chubsucker

The lake chubsucker is a freshwater fish endemic to North America, found in the Great Lakes and the Mississippi River basin, as far north as Ontario, Canada, extending south to the Gulf of Mexico. It is mainly found in lakes, ponds, and swamps, rarely in streams.

Gilt darter

The gilt darter is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It can be found in a number of states in the Mississippi River drainage of the United States although it has been extirpated from some river systems in which it was at one time present, mostly due to siltation and pollution problems. Males are more colorful than females and can grow to a length of about 9 cm (3.5 in). It is a benthic fish that feeds primarily on small aquatic insect larvae. Males form territories during the breeding season in late spring and early summer. Spawning typically takes place at the upper ends of riffles with sandy and gravelly bottoms interspersed with larger cobbles. Some organisations are endeavouring to conserve populations of the gilt darter and re-introduce it to states where the fish has been extirpated but suitable habitat still exists.

Index of biodiversity articles Wikipedia index

This is a list of topics in biodiversity.

British Columbia hosts 22 species of native and introduced salmonids. This list reflects the conservation status of British Columbia salmonids. Status from BC Species and Ecosystems Explorer. Status definitions from NatureServe.

<i>Acalypha virginica</i>

Acalypha virginica, commonly called Virginia threeseed mercury or Virginia copperleaf, is a plant in the spurge family (Euphorbiaceae). It is native to the eastern United States. It is found in a variety of natural habitats, particularly in open woodlands and along riverbanks. It is a somewhat weedy species that responds positively to ecological disturbance, and can be found in degraded habitats such as agricultural fields.


  1. NatureServe Explorer website
  2. 1 2 3 4 "NatureServe Conservation Status". NatureServe Explorer. NatureServe Inc. Retrieved 18 December 2013.