Biodiversity: Levels, Hotspots, Threats and Global Frameworks

What biodiversity means

Biodiversity is the variety of life at all levels. The term was popularised by E.O. Wilson. It has three levels:

1. Genetic diversity: variation within a species, such as India's thousands of rice varieties. It is the basis of adaptation and crop breeding.
2. Species diversity: the number and abundance of species. It is measured by species richness and evenness.
3. Ecosystem diversity: the variety of habitats, such as forests, grasslands, wetlands, deserts, reefs and mountains.

Diversity indices:

• Alpha diversity: within a community.
• Beta diversity: between communities along a gradient.
• Gamma diversity: across a whole region.

Species distribution: about 1.8–2 million species have been described worldwide, but estimates of the total run to about 8.7 million. Species richness is highest in the tropics and decreases towards the poles (the latitudinal gradient).

India: a megadiverse country

India is one of 17 megadiverse countries. It has about 2.4% of the world's land area but about 7–8% of recorded species:

• about 1,04,000 animal species (Zoological Survey of India);
• about 55,000 plant species (Botanical Survey of India).

Biogeographic zones: India has 10 zones (Rodgers and Panwar), for example:

• the Trans-Himalaya;
• the Himalaya;
• the Desert;
• the semi-arid zone;
• the Western Ghats;
• the Deccan Peninsula (the largest);
• the Gangetic Plain;
• the North-East;
• the coasts;
• the islands.

Endemism: India has high endemism. About a third of its plants are found nowhere else, and endemism is especially high in amphibians of the Western Ghats.

Biodiversity hotspots: a concept introduced by Norman Myers (1988) and used by Conservation International. A hotspot must:

• have at least 1,500 endemic vascular plant species;
• have lost at least 70% of its original habitat.

There are 36 hotspots worldwide. India has parts of four:

• the Himalaya;
• Indo-Burma (the North-East, except Assam's Brahmaputra plains, and the Andaman Islands);
• the Western Ghats and Sri Lanka;
• Sundaland (the Nicobar Islands).

Threats to biodiversity: "HIPPO"

• Habitat loss and fragmentation: the leading cause, through agriculture, infrastructure, mining and urbanisation.
• Invasive alien species:
• *Lantana camara* has spread over a large share of India's tiger habitat;
• water hyacinth (*Eichhornia*);
• *Prosopis juliflora*;
• African catfish in wetlands;
• *Parthenium*.
• Pollution: pesticides, plastics, nutrients.
• Population pressure and overconsumption.
• Overexploitation: poaching, the illegal wildlife trade, overfishing.

Climate change is increasingly a leading threat. Disease is another: chytrid fungus in amphibians, and the diclofenac-driven collapse of vultures in India in the 1990s–2000s (diclofenac was banned for veterinary use in 2006, and ketoprofen and aceclofenac for veterinary use in 2023).

Global assessment: the IPBES Global Assessment (2019) warned that about 1 million species face extinction, many within decades. The WWF Living Planet Report 2024 found a 73% average decline in monitored wildlife populations since 1970.

IUCN Red List categories:

• Extinct (EX);
• Extinct in the Wild (EW);
• Critically Endangered (CR);
• Endangered (EN);
• Vulnerable (VU);
• Near Threatened (NT);
• Least Concern (LC);
• Data Deficient (DD).

CR, EN and VU are together "threatened". Indian examples:

• CR: great Indian bustard, gharial, pygmy hog, white-rumped vulture, Namdapha flying squirrel;
• EN: tiger, Asian elephant, red panda, Ganges river dolphin;
• VU: snow leopard, one-horned rhino.

Extinct in India: the Asiatic cheetah, declared extinct in 1952. Project Cheetah introduced African cheetahs at Kuno National Park (Madhya Pradesh) from September 2022, with a second site at Gandhi Sagar (MP) from 2025. Mortality and habitat suitability have been concerns.

Global biodiversity frameworks

Convention on Biological Diversity (CBD): adopted at the Rio Earth Summit (1992), in force since 1993. Its three objectives:

1. conservation;
2. sustainable use;
3. fair and equitable sharing of benefits from genetic resources.

Protocols:

• the Cartagena Protocol (2000) on biosafety (living modified organisms);
• the Nagoya Protocol (2010) on Access and Benefit Sharing (ABS).

Kunming–Montreal Global Biodiversity Framework (COP15, December 2022): 23 targets for 2030, including:

• the "30x30" target: protect 30% of land and 30% of oceans by 2030;
• restore 30% of degraded ecosystems;
• halve excess nutrient loss and pesticide risk;
• cut harmful subsidies by $500 billion a year;
• mobilise $200 billion a year for biodiversity.

COP16 (Cali, Colombia, 2024) created the Cali Fund for benefits from digital sequence information (DSI) and a permanent subsidiary body for Indigenous peoples.

India updated its National Biodiversity Strategy and Action Plan in 2024 to align with the framework.

Other conventions:

• CITES (1973): regulates international trade in endangered species through Appendices I, II and III;
• the Convention on Migratory Species (CMS), Bonn (1979). India hosted CMS COP13 at Gandhinagar in 2020;
• Ramsar (1971) for wetlands;
• the World Heritage Convention (1972);
• the International Whaling Commission;
• the BBNJ Agreement (High Seas Treaty, 2023), which entered into force in January 2026 after 60 ratifications. India signed it in 2024.

India's legal and institutional framework

• Biological Diversity Act 2002, amended in 2023. It sets up a three-tier structure:
• the National Biodiversity Authority (Chennai);
• State Biodiversity Boards;
• Biodiversity Management Committees (BMCs) at the local level, which maintain People's Biodiversity Registers.

The 2023 amendment decriminalised offences, eased rules for AYUSH practitioners, and promoted cultivation of medicinal plants. Critics said it weakened benefit sharing.

• Wildlife (Protection) Act 1972: next lesson.
• Botanical Survey (1890) and Zoological Survey (1916).

Ex-situ conservation:

• zoos (the Central Zoo Authority, 1992);
• botanical gardens;
• gene banks: the National Bureau of Plant Genetic Resources in Delhi, holding over 4.5 lakh accessions, and the high-altitude Chang La seed vault in Ladakh;
• cryopreservation;
• captive breeding, such as vultures at Pinjore and gharials.

Analysis

Why biodiversity is valuable:

• Ecosystem services: provisioning (food, timber, medicine), regulating (pollination, climate, water purification), cultural (spiritual, recreational) and supporting (soil formation, nutrient cycling).
• Economic value: about half of global GDP is moderately or highly dependent on nature (WEF, 2020).

Debates:

• Fortress conservation vs community-based approaches. The Forest Rights Act 2006 recognises the rights of forest dwellers. Over 80% of the world's remaining biodiversity is in territories of Indigenous peoples.
• The 30x30 target could displace communities if it is pursued through strict protected areas only. OECMs (other effective area-based conservation measures), such as sacred groves and community reserves, offer an alternative.

Common prelims traps

• India has parts of four hotspots; the Nicobar Islands belong to Sundaland.
• A hotspot needs 1,500 endemic plants and at least 70% habitat loss.
• CITES regulates trade, not habitat protection.
• The Nagoya Protocol deals with ABS; the Cartagena Protocol with biosafety.

Quick self-test

1. *What is the difference between endangered and critically endangered?* The degree of extinction risk measured against IUCN criteria (CR is the highest risk in the wild).
2. *What does 30x30 mean?* Protecting 30% of land and sea by 2030.
3. *Which Indian bird collapsed because of a veterinary drug?* Vultures, from diclofenac.

Practice: Mains question

*"Invasive alien species are a silent threat to India's biodiversity." Discuss with examples, and suggest measures. (150 words)*