English · हिन्दी · తెలుగు · தமிழ் · മലയാളം · मराठी · ಕನ್ನಡ

Value, threats, the Red List and conservation

Biodiversity · Part 2 / 2 · Fact-checked on 8 November 2026 · how we check

Written with AI from the sources listed at the bottom of this page, then fact-checked by a separate AI.

Direct values and ecosystem services; the rivet popper hypothesis; the evil quartet of threats; background and mass extinctions; the IUCN Red List and its categories; in situ and ex situ conservation, sacred groves, seed and gene banks; India's biodiversity institutions.

Part 1 showed where life is richest. This part asks why that richness matters, what is destroying it and how it is protected. It runs in a line: the value of biodiversity, including the services ecosystems perform for free; the forces that push species towards extinction and the record of past extinctions; the IUCN Red List that measures the danger; and the two families of conservation, protecting life where it lives and saving it elsewhere, with the Indian institutions that do this work.

The plainest value of biodiversity is what people take from it directly. Every crop and farm animal was once wild, and the wild relatives of crops still carry genes for resisting pests, drought and disease. Many medicines started as chemicals made by plants. Quinine, long the main drug against malaria, came from the bark of the cinchona tree; aspirin traces its origin to salicin, a compound in willow bark; and the Madagascar periwinkle is the plant source of vincristine and vinblastine, two drugs used to treat cancer. Searching living things for new drugs, genes and products is called bioprospecting, and species-rich countries have demanded a fair share of the gains, a principle the Convention on Biological Diversity accepts. Timber, fibre, fuelwood, honey, resins and fish complete the list, and many forest and coastal communities in India live on them.

Less visible, and far larger in value, is the work ecosystems do without being asked. These benefits are called ecosystem services. The Millennium Ecosystem Assessment, a global study backed by the United Nations and published in 2005, sorted them into four groups. Provisioning services are the goods themselves: food, fresh water, wood and medicine. Regulating services keep conditions stable: forests hold soil and soften floods, wetlands filter water, mangroves absorb storm surges and insects pollinate crops. Cultural services are the spiritual, recreational and aesthetic meaning people find in nature, from a sacred grove to a tiger safari. Supporting services such as soil formation, nutrient cycling and photosynthesis underlie all the rest. Beside these uses stands an ethical argument: each species is the result of a long evolutionary history, and many hold that humans have no right to end it.

Does it matter if a few species vanish from a rich ecosystem? The Stanford ecologist Paul Ehrlich answered with an image. Think of the many thousands of rivets that fasten an aircraft together. Removing them one by one might cause no visible trouble for a while, but sooner or later the aircraft becomes unsafe to fly, and losing a rivet that holds a wing matters far more than losing several from a passenger seat. Each lost species likewise weakens an ecosystem a little, and the loss of a keystone species can bring on a collapse. This is the rivet popper hypothesis. Experiments back the broad idea: in long-running grassland plots in Minnesota, the American ecologist David Tilman found that plots with more species showed smaller swings in total plant growth from year to year. Diversity works like insurance for an ecosystem.

The geographer and biologist Jared Diamond grouped the chief causes of extinction into an 'evil quartet'. First and worst is habitat loss and fragmentation: clearing a forest or draining a wetland removes homes outright, and cutting a large habitat into small patches hurts most the animals that need wide ranges, such as elephants and tigers. Second is overexploitation, harvesting faster than a population can recover; Steller's sea cow was hunted out within about thirty years of its discovery, and the passenger pigeon, once abundant across North America, ended with the death of the last bird in a zoo in 1914. Third come invasive species: after the Nile perch was introduced into Lake Victoria, a large number of the lake's native cichlid species disappeared, and in India lantana, parthenium and water hyacinth smother native plants. Fourth is co-extinction, where a species takes its dependants with it, such as its own parasites or a plant served by a single pollinator. Pollution and climate change now add to all four.

Extinction in itself is natural. Species have always disappeared at a slow background rate as conditions shifted, while new ones arose. Five times, though, extinction has swept away a large share of all species within a short span of geological time; these are the five mass extinction events. The largest closed the Permian period about 252 million years ago, when most marine species died out. The best known, about 66 million years ago at the end of the Cretaceous, ended the non-bird dinosaurs and is tied to an asteroid impact. Many scientists now describe a sixth mass extinction under way, caused this time by a single species, our own. The 2019 global assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) estimated that about one million animal and plant species face extinction, many within decades. India's own loss is the cheetah, declared extinct in the country in 1952; cheetahs from Namibia were released in Kuno National Park, Madhya Pradesh, in September 2022.

How close a species stands to extinction is judged by the IUCN Red List of Threatened Species, maintained by the International Union for Conservation of Nature. Founded in 1948, with its headquarters at Gland in Switzerland, the IUCN is unusual in having both governments and non-governmental organisations as members. The Red List, begun in 1964, assigns each assessed species to one of nine categories using measurable tests, such as the speed of population decline, the size of the range and the number of mature individuals left. Only three categories, Critically Endangered, Endangered and Vulnerable, are counted as 'threatened'. Indian examples fix the scale: the great Indian bustard and the gharial are Critically Endangered, the tiger is Endangered and the greater one-horned rhinoceros is Vulnerable. The list is a scientific assessment and has no legal force; in India, legal protection comes from the schedules of the Wild Life (Protection) Act, 1972.

in situ conservation means protecting species in their natural homes, together with the ecosystems they depend on. It is generally preferred because it saves whole communities at once and lets species go on evolving in natural conditions. In India its main legal form is the network of protected areas, national parks, wildlife sanctuaries, conservation reserves and community reserves, along with tiger reserves and biosphere reserves, which the next chapter covers. But in situ conservation is older than any statute. All over India, communities have left patches of forest untouched as sacred groves dedicated to a local deity: they go by many local names, for example kavu in Kerala, devrai in Maharashtra, law kyntang in Meghalaya and sarna in Jharkhand, and many still hold old trees and rare plants lost from the land around them. The Bishnoi community of Rajasthan guards khejri trees and blackbuck; in 1730 Amrita Devi and many others of the community were killed at Khejarli while resisting the felling of khejri trees.

ex situ conservation means keeping species alive outside their natural habitat, usually because the wild population is too small or too threatened to last on its own. Zoos, botanical gardens and safari parks hold living animals and plants, and captive breeding can raise numbers for release. India's vulture breeding centre at Pinjore in Haryana was started after three Gyps vulture species crashed, poisoned by the painkiller diclofenac in the carcasses of treated cattle. For plants and genetic material, storage is the main tool. Seed banks keep dried seeds cold for decades; field gene banks grow living collections of crops that cannot be kept as seed; and cryopreservation holds sperm, eggs, embryos, pollen or tissue in liquid nitrogen at about minus 196 °C. The National Bureau of Plant Genetic Resources (NBPGR) in New Delhi runs India's national gene bank. Globally, the Svalbard Global Seed Vault, cut into a mountain on a Norwegian Arctic island and opened in 2008, keeps back-up copies of seed from gene banks worldwide.

What India knows about its living wealth rests largely on two old survey bodies. The Botanical Survey of India, set up in 1890, explores and documents the country's plants, and the Zoological Survey of India, founded in 1916, does the same for animals; both are headquartered in Kolkata and publish the official counts of Indian flora and fauna. The Wildlife Institute of India at Dehradun, established in 1982, trains wildlife managers and conducts research. To carry out India's duties under the Convention on Biological Diversity, Parliament passed the Biological Diversity Act, 2002. It created three tiers: the National Biodiversity Authority, set up in 2003 and based in Chennai; State Biodiversity Boards; and Biodiversity Management Committees in local bodies, which prepare People's Biodiversity Registers recording local species and traditional knowledge.

The part answers three linked questions. Why save biodiversity? Because it feeds and heals people, its services are worth far more than its goods, and, like rivets in an aeroplane, each species steadies the whole. What threatens it? The evil quartet, now joined by pollution and climate change, driving what many call a sixth mass extinction. How is it protected? The IUCN Red List measures the risk; in situ conservation guards species in their homes through protected areas and community traditions such as sacred groves; ex situ conservation keeps a reserve in zoos, gardens, seed and gene banks. The two approaches complement each other: a vulture bred in captivity is of little use without safe skies and carcasses free of poison to return to.

Exam traps

• Jared Diamond's 'evil quartet' has four members: the loss and breaking-up of habitats, over-harvesting, alien invaders (invasive species) and CO-EXTINCTION. Pollution and climate change are serious but are not among the original four.
• The rivet popper image comes from Paul EHRLICH; the long-term grassland plots of David Tilman supplied the evidence that species-rich plots are more stable in productivity.
• Only CR, EN and VU are 'threatened' categories. Near Threatened, Least Concern and Data Deficient are NOT threatened.
• Extinct in the Wild (EW) is not Extinct (EX): an EW species still survives in captivity or cultivation.
• The IUCN Red List has NO legal force; legal protection in India comes from the Wild Life (Protection) Act, 1972. IUCN is headquartered at Gland, Switzerland, not Geneva.
• IN SITU means inside the natural habitat: sacred groves, national parks, biosphere reserves. EX SITU means outside it: zoos, botanical gardens, seed and gene banks, and cryopreservation.
• The largest mass extinction was the END-PERMIAN (about 252 million years ago), not the end-Cretaceous that ended the dinosaurs.
• India's national gene bank is run by the NBPGR, New Delhi; the Svalbard Global Seed Vault is in NORWAY.

Recap

• Direct values: food, medicine (quinine, aspirin's origin in willow, vincristine from periwinkle), fibre, timber; bioprospecting.
• Ecosystem services (Millennium Ecosystem Assessment, 2005): provisioning, regulating, cultural, supporting.
• Rivet popper hypothesis (Paul Ehrlich): each lost species weakens the ecosystem; Tilman showed diversity stabilises productivity.
• Evil quartet (Jared Diamond): habitat loss and fragmentation, overexploitation, invasive species, co-extinction.
• Five mass extinctions; the end-Permian (about 252 million years ago) was the largest; many speak of a sixth, caused by humans (IPBES 2019: about one million species at risk).
• Cheetah declared extinct in India in 1952; cheetahs from Namibia released in Kuno National Park in September 2022.
• IUCN (1948, Gland); Red List (1964); nine categories; CR, EN and VU are threatened; no legal force.
• In situ: protected areas, sacred groves (devrai, kavu, sarna, law kyntang), Bishnoi tradition. Ex situ: zoos, gardens, captive breeding (Pinjore vultures), seed and gene banks, cryopreservation at about minus 196 °C.
• NBPGR runs the national gene bank; Svalbard Global Seed Vault (Norway, 2008).
• BSI (1890) and ZSI (1916), both Kolkata; WII Dehradun (1982); NBA Chennai (2003), State Biodiversity Boards, BMCs and People's Biodiversity Registers.

Practice questions

Sources

• Ministry of Environment, Forest and Climate Change: India's national reports to the Convention on Biological Diversity and the National Biodiversity Action Plan; Botanical Survey of India and Zoological Survey of India material on India's flora, fauna and endemism — https://moef.gov.in
• Convention on Biological Diversity, 1992 (text), and the Biological Diversity Act, 2002 — https://www.cbd.int/convention/text
• Ministry of Environment, Forest and Climate Change: National Wildlife Action Plan and material on threatened species and the Wild Life (Protection) Act, 1972 — https://moef.gov.in
• Millennium Ecosystem Assessment (2005), Ecosystems and Human Well-being: categories of ecosystem services and drivers of biodiversity change — https://www.millenniumassessment.org
• IUCN Red List of Threatened Species: categories and criteria; IPBES Global Assessment Report on Biodiversity and Ecosystem Services (2019) — https://www.iucnredlist.org
• ICAR-National Bureau of Plant Genetic Resources: the National Genebank, seed storage, field genebanks and cryopreservation — https://nbpgr.ernet.in