Summary of 2006 IUCN Red List categories.

The ''Red List Index (RLI)'', based on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

of Threatened Species, is an indicator of the changing state of global

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...

. It defines the

conservation status The conservation status of a group of organisms (for instance, a species) 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 ...

of major

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

groups, and measures trends in

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

risk over time. By conducting conservation assessments at regular intervals, changes in the threat status of species in a

taxonomic group In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

can be used to monitor trends in extinction risk. RLIs have been calculated for

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

s and

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

s, using changes in threat status for species in each of the groups. As well as taxonomic groups, RLIs can show trends in extinction risk according to

biogeographic Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...

realm,

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

type, and dominant threat process.

Sampled approach

Producing indices of change in extinction risk by comprehensively assessing whole species groups, while feasible for well studied groups with relatively few species, is not suitable for all taxonomic groups. Assessing every species in the larger and lesser known groups which comprise the majority of the world’s biodiversity, such as

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

, invertebrates (particularly

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s) and

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

s, is not practical. The ''Red List Index (sampled approach) (SRLI)'' has been developed in order to determine the threat status and also trends of lesser-known and less charismatic species groups. It is a collaboration between IUCN members and is coordinated through the

Institute of Zoology The Institute of Zoology (IoZ) is the research division of the Zoological Society of London (ZSL) in England. It is a government-funded research institute specialising in scientific issues relevant to the conservation of animal species and their hab ...

(IoZ), the research division of the

Zoological Society of London The Zoological Society of London (ZSL) is a charity devoted to the worldwide conservation of animals and their habitats. It was founded in 1826. Since 1828, it has maintained the London Zoo, and since 1931 Whipsnade Park. History On 29 ...

(ZSL). The SRLI is based on a representative sample of species selected from taxonomic groups within animals (

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s and

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

s),

and

s. Assessment of the selected species will provide baseline information on the current status of biodiversity. Reassessment at regular intervals will identify changes in threat status over time to provide a more broadly representative picture of biodiversity change.

Applications

The aim is that the SRLI will aid in the production of a global biodiversity indicator capable of measuring whether the rate of

biodiversity loss Biodiversity loss includes the worldwide extinction of different species, as well as the local reduction or loss of species in a certain habitat, resulting in a loss of biological diversity. The latter phenomenon can be temporary or permanent, de ...

has been reduced. In addition, it will help to develop a better understanding of which taxonomic groups, realms or

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

s are deteriorating the most rapidly, why species are threatened, where they are threatened, what conservation actions exist and which actions are needed. The aim is to provide policy makers, resource managers, scientists, educators, conservation practitioners and the general public with more thorough knowledge of biodiversity change and further tools with which to make informed decisions. In April 2002 at the

Convention on Biological Diversity The Convention on Biological Diversity (CBD), known informally as the Biodiversity Convention, is a multilateral treaty. The Convention has three main goals: the conservation of biological diversity (or biodiversity); the sustainable use of its ...

(CBD), 188 Nations committed themselves to actions to: ''“… achieve, by 2010, a significant reduction of the current rate of biodiversity loss at the global, regional and national levels…”'' The RLI has been adopted by the CBD as one of the indicators to measure progress towards this important target, and specifically to monitor changes in threat status of species.

References

* * * * *

External links

IUCN: The IUCN Red List website

* ttp://threatenedplants.myspecies.info/ Sampled Red List Index for Plants
Plants at Risk
{{Extinction

Sampled approach

Applications

See also

References

External links