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 an inventory of the global conservation status and extinction risk of biological ...

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

biodiversity Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...

. 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 A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

groups, and measures trends in

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

risk over time. By conducting conservation assessments at regular intervals, changes in the threat status of species in a taxonomic group 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 (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s and

amphibian Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

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 realm,

habitat In ecology, habitat refers to the array of resources, 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 manifestation of its ...

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 ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

, invertebrates (particularly

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s) and

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

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 (IoZ), the research division of the

Zoological Society of London The Zoological Society of London (ZSL) is a charity and organization devoted to the worldwide animal conservation, conservation of animals and their habitat conservation, habitats. It was founded in 1826. Since 1828, it has maintained London Zo ...

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

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s and

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

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 happens when plant or animal species disappear completely from Earth (extinction) or when there is a decrease or disappearance of species in a specific area. Biodiversity loss means that there is a reduction in Biodiversity, b ...

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) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

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 IUCN Red List

Sampled approach

Applications

See also

References

External links