What are Rare , Endangered and Threatened (RET) Species
In order to categorize threatened species, IUCN ( International Union for Conservation of Nature) has updated the categories on the basis of geographical range, population and fragmentation. The threatened species categories now used in the Red Data Books and the Red List are critically endangered (facing an extremely high risk of extinction in the wild in the immediate future), endangered (not critical, but facing a very high risk of extinction in the wild in the near future), and vulnerable (not critical or endangered but facing a high risk of extinction in the wild in the medium-term future). Taxa listed as critically endangered qualify for vulnerable and endangered, and those listed as endangered qualify for vulnerable. Together these categories are described as ‘threatened’.
Need for Conservation of RET Tree species
In 2006, scientists have found that many tree and shrub species, many of them endemic to the Western Ghats, have become rare and endangered with encroachments, overexploitation of these species and agricultural activity eating into the habitats where they once grew.
Fifty scientists from six states recorded and analyzed around 2.25 lakh individual plants (trees, shrubs and herbs) that are enumerated in the entire biodiversity hotspot in Western Ghats. The 388 (rare and endangered) species were represented by only one individual meaning they encountered these species just once. Of the 2.25 lakh individual plants enumerated 1,669 were tree species and 1,241 were shrub species. Scientists found introduced species in higher numbers. These non-native species now dominate the Western Ghats. Scientists said that fresh water swamps (Karnataka and Kerala),lateritic outcrops (Maharashtra) and Shola forest (south Western Ghat) were the most critical habitats in Western Ghats. All these areas are under tremendous pressure from encroachments and conversion into agricultural land, they say. They also found that areas in the north of Palghat (Kerala ) and in northern parts of Maharashtra in Western Ghats were under serious threat and a worrisome drop in native species of trees even as an invasive species, Lantana camara has spread over 60 % of the Western Ghat. Scientists said if not controlled, the species could be a potential threat to the native species here.
Most of the RET species also have nutritional/ medicinal value which is used in local tribal medicine. Conservation of this species would also ensure there is higher availability of these species for local health care which is community driven.