Biodiversity of India
Biodiversity of India
India is one of the 17 megadiverse countries of the world, hosting about 7-8% of the world's recorded species in just 2.4% of the global land area. India has 4 biodiversity hotspots, diverse ecosystems, and a rich heritage of endemic flora and fauna.
Key Dates
India has about 1,00,000+ animal species and 45,500+ plant species documented
Western Ghats, Eastern Himalayas, Indo-Burma, Sundaland (Nicobar Islands)
Hailey National Park (now Jim Corbett) established — India's first National Park
Wildlife Protection Act — framework for protecting wild animals and plants
Nilgiri declared India's first Biosphere Reserve under UNESCO MAB Programme
India signs Convention on Biological Diversity (CBD) at Rio Earth Summit
Biological Diversity Act enacted by Indian Parliament; NBA established in Chennai
Gangetic River Dolphin declared India's National Aquatic Animal
India has 106 National Parks and 567 Wildlife Sanctuaries (as of 2023)
About 33% of Indian flora is endemic — found nowhere else in the world
India has 172+ species categorized as Critically Endangered by IUCN
India divided into 10 biogeographic zones (Rodgers & Panwar classification)
India's tiger population reported at 3,682 in 4th All India Tiger Estimation
India surpasses 75 Ramsar wetland sites; many more added through 2024
India is a Vavilov Centre of origin for rice, mango, citrus, sugarcane, pepper, turmeric
India as a Megadiverse Country
India is one of 17 megadiverse countries identified by the World Conservation Monitoring Centre (WCMC). It harbours about 7-8% of all globally recorded species: over 50,000 plant species (including about 18,000 flowering plants), over 1,00,000 animal species (including about 2,500+ fish, 240+ amphibians, 530+ reptiles, 1,350+ birds, and 430+ mammals). India lies at the confluence of three biogeographic realms: Palearctic (Himalayan), Indo-Malayan (peninsular), and Afrotropical (western India), which contributes to this extraordinary diversity. India also has high genetic diversity in crops and their wild relatives — it is a centre of origin/diversity for rice, mango, citrus, sugarcane, banana, pepper, turmeric, and many pulses. About 33% of Indian flora is endemic — found nowhere else in the world.
Biodiversity Hotspots in India
India has 4 of the world's 36 biodiversity hotspots (areas with at least 1,500 endemic vascular plant species and having lost at least 70% of original habitat): (1) Western Ghats — stretches from Gujarat to Kerala; exceptionally high endemism with about 5,000+ flowering plants (1,700+ endemic), 508 bird species, 179 amphibians (80%+ endemic); Lion-tailed Macaque, Malabar Giant Squirrel, Nilgiri Tahr are flagship species; UNESCO World Heritage Site; (2) Eastern Himalayas — covers NE India, Bhutan, southern China; known for rhododendrons (about 30 species), orchids, and rare animals like Red Panda, Snow Leopard, Golden Langur; (3) Indo-Burma — covers NE India (Manipur, Mizoram, Nagaland), Myanmar, Thailand; rich in freshwater turtle diversity and endemic fish; includes Loktak Lake wetland; (4) Sundaland — extends to the Nicobar Islands; hosts the Nicobar Megapode, Nicobar Pigeon, and saltwater crocodiles.
Biogeographic Zones of India
India is divided into 10 biogeographic zones (Rodgers & Panwar, 1988): (1) Trans-Himalayan — Ladakh UT, cold desert, sparse vegetation, snow leopard, Tibetan wild ass (kiang), black-necked crane; highest plateau in India (4,500+ m); (2) Himalayan — from Shivalik foothills to alpine meadows; musk deer, Himalayan black bear, red panda; 3 sub-zones: Western, Central, Eastern Himalaya; (3) Indian Desert — Thar Desert; Great Indian Bustard, Indian Wild Ass (khur in Little Rann of Kutch), chinkara; Desert NP in Jaisalmer; (4) Semi-Arid — Rajasthan, Gujarat, Punjab; Gir NP with Asiatic Lion; dry deciduous and thorn forests; (5) Western Ghats — high endemism; shola-grassland ecosystems; described above; (6) Deccan Peninsula — dry deciduous forests; blackbuck, four-horned antelope, Indian wolf; plateau basalt terrain; (7) Gangetic Plain — intensely cultivated alluvial plain; Gangetic dolphin (national aquatic animal), gharial; severely degraded habitats; (8) Coasts — mangroves (Sundarbans largest), coral reefs (Gulf of Mannar, Lakshadweep), marine turtles; (9) Northeast — exceptionally biodiverse; one-horned rhinoceros (Kaziranga), hoolock gibbon (India's only ape), clouded leopard; (10) Islands — Andaman & Nicobar and Lakshadweep; dugong, Nicobar pigeon, coral reef ecosystems; high endemism due to isolation.
Endemic & Threatened Species
India's important endemic species include: Asiatic Lion (only in Gir, Gujarat), Lion-tailed Macaque (Western Ghats), Nilgiri Tahr (Western Ghats), Indian Giant Squirrel/Malabar Giant Squirrel (Western Ghats), Sangai Deer/Brow-antlered Deer (only in Keibul Lamjao, Manipur), Golden Langur (Assam-Bhutan border), Namdapha Flying Squirrel (Arunachal Pradesh), Pygmy Hog (Assam). Critically Endangered species on IUCN Red List include: Great Indian Bustard (<150), Bengal Florican, Indian Vulture, White-rumped Vulture, Pygmy Hog, Malabar Large-spotted Civet, and several freshwater fish/turtles. Schedule I of WLPA 1972 provides the highest legal protection. Key conservation projects: Project Tiger (1973), Project Elephant (1992), Project Snow Leopard (2009), Indian Rhino Vision 2020, Vulture Conservation Programme, Sea Turtle Conservation, and Project Dolphin (2020).
Biodiversity Conservation Framework
Legal framework: Wildlife Protection Act 1972 (provides for protected areas and species protection; amended 2022), Forest Conservation Act 1980 (restricts diversion of forest land; amended 2023), Biological Diversity Act 2002 (establishes NBA-SBB-BMC 3-tier structure; amended 2023), Forest Rights Act 2006 (recognizes rights of forest-dwelling communities). India is a party to CBD, CITES, CMS (Bonn), Ramsar Convention, and World Heritage Convention. In-situ: 106 National Parks, 567 WLSs, 18 Biosphere Reserves (12 in UNESCO World Network), 85 Ramsar Sites, Conservation Reserves, Community Reserves. Ex-situ: zoological gardens, botanical gardens, gene banks (NBPGR), seed banks, cryopreservation. National Wildlife Action Plan (2017-31) guides the strategic framework. National Mission for Green India under NAPCC aims to increase forest cover.
Three Levels of Biodiversity
Biodiversity operates at three hierarchical levels: (1) Genetic diversity — variation in genes within a species; India is a Vavilov Centre of origin for many crop plants; NBPGR (National Bureau of Plant Genetic Resources, New Delhi) conserves over 4.5 lakh accessions of crop germplasm; high genetic diversity in wild rice varieties (Oryza nivara, O. rufipogon) ensures food security; (2) Species diversity — variety of species in a region; measured by species richness (total count) and species evenness (relative abundance); India's species diversity is highest in the Western Ghats and NE India; (3) Ecosystem diversity — variety of habitats, communities, and ecological processes; India has tropical rainforests, alpine meadows, deserts, wetlands, coral reefs, mangroves, grasslands, and temperate forests — making it one of the most ecosystem-diverse nations. Alpha diversity = within habitat; Beta diversity = between habitats; Gamma diversity = regional.
Patterns of Biodiversity Distribution
Latitudinal gradient: species diversity generally increases from poles to equator — tropics harbour 2/3 of all species; India, being largely tropical/subtropical, has high diversity. Altitudinal gradient: diversity decreases with altitude (fewer species above 4,000 m); Himalayan biodiversity peaks in 1,000-3,000 m belt. Species-Area Relationship: S = cA^z (where z = 0.1-0.3 for continental areas, 0.6-1.2 for island biogeography); explains why larger national parks harbour more species. Rivet Popper Hypothesis (Paul Ehrlich): losing species is like losing rivets from an airplane — initially no visible damage, but eventually catastrophic failure. Keystone species: species whose removal causes disproportionate ecosystem collapse (e.g., fig trees, pollinators, elephants as ecosystem engineers). Foundation species: species that create habitat structure (e.g., corals in reef ecosystems, mangrove trees).
Forest Types and Biodiversity
Champion & Seth Classification (1968) recognizes 16 major forest types and 221 sub-types in India. Major types: (1) Tropical Wet Evergreen — Western Ghats (south of 15 degrees N), NE India, Andaman; >250 cm rainfall; dense canopy, epiphytes; rosewood, ebony; (2) Tropical Semi-Evergreen — NE India, lower slopes of Western Ghats; 200-250 cm rainfall; (3) Tropical Moist Deciduous — largest area (Sal, teak dominant); central India (MP, Chhattisgarh, Odisha); 100-200 cm; (4) Tropical Dry Deciduous — most widespread; central + southern plateau; <100 cm; teak, tendu, palash; (5) Tropical Thorn — Rajasthan, Gujarat; <50 cm; babool, khejri, cacti; (6) Sub-Tropical — Himalayan foothills; pine (chir pine in W Himalaya); (7) Temperate — mid-altitudes; oak, deodar, spruce, fir; (8) Alpine — above treeline; rhododendron, juniper, birch. India's forest cover: 7,13,789 sq km = 21.71% of geographical area (ISFR 2021). Madhya Pradesh has the largest forest cover area; Mizoram has the highest forest cover percentage.
Mangrove Ecosystems
Mangroves are salt-tolerant trees/shrubs found in tropical/subtropical intertidal zones. India's mangrove cover: 4,992 sq km (ISFR 2021). Sundarbans (West Bengal) is the largest mangrove forest in India and the world — about 4,200 sq km on Indian side; UNESCO World Heritage Site; home to Royal Bengal Tiger. Other important mangrove areas: Bhitarkanika (Odisha) — 2nd largest; salt-water crocodile breeding; Gujarat (Gulf of Kutch, Gulf of Khambhat); Andaman & Nicobar; Pichavaram (Tamil Nadu); Godavari-Krishna delta (AP). Mangroves provide: coastal protection (cyclone buffer — Bhitarkanika saved villages during 1999 Odisha super cyclone), nursery for fish/shrimp, blue carbon sinks (3-5x more carbon per unit area than terrestrial forests), prevent coastal erosion, filter pollutants. Threats: shrimp farming, urbanization, industrial effluents, sea-level rise. Mangrove for the Future (MFF) — IUCN initiative for South/SE Asia.
Coral Reef Ecosystems
Coral reefs are called "rainforests of the sea" — support ~25% of marine species on <1% of ocean floor. India has 4 major coral reef areas: (1) Gulf of Kutch (Gujarat) — fringing reefs; faces industrial pollution from Jamnagar refineries; (2) Gulf of Mannar (TN) — India's first Marine Biosphere Reserve (2001); 21 islands; dugong habitat; (3) Andaman & Nicobar — largest extent; fringing reefs around most islands; (4) Lakshadweep — atoll-type reefs; largest atoll system in India; high fish diversity. Coral bleaching: caused by elevated sea surface temperatures (SST); zooxanthellae algae expelled → coral turns white → death if prolonged. Major bleaching events: 1998, 2010, 2016, 2020. Threats: warming, ocean acidification (CO2 absorption lowers pH), sedimentation, destructive fishing (dynamite, cyanide). India's Coral Reef Monitoring Network established by MoEFCC. CZRMA (Coastal Zone Regulation and Management Authority) regulates coastal activities.
Grassland and Savanna Ecosystems
India's grasslands are highly threatened and under-recognized. Types: (1) Shola grasslands — montane grasslands interspersed with stunted forests (shola forests) in Western Ghats above 1,500 m; Nilgiri Tahr habitat; crucial for water catchment; unique plant-grassland mosaic; (2) Terai grasslands — alluvial floodplain grasslands of northern India; habitat for one-horned rhinoceros (Kaziranga, Dudhwa), Bengal florican, Barasingha; threatened by encroachment and agriculture; (3) Banni grasslands (Gujarat) — largest natural grassland in Asia (~2,600 sq km); Banni buffalo breed; threatened by Prosopis juliflora invasion; (4) Deccan grasslands — semi-arid; habitat for Great Indian Bustard, Indian Wolf, Blackbuck; severely converted to agriculture; (5) Alpine meadows (bugyals) — above treeline in Uttarakhand, HP, Sikkim; seasonal grazing grounds; wildflower diversity. India has no dedicated grassland conservation policy — a major gap.
Wetland Biodiversity
India has ~7.5 lakh hectares of wetlands (4.63% of geographical area). Important wetlands: Chilika Lake (Odisha) — largest brackish water lagoon in Asia; Irrawaddy dolphins; Nalabana bird sanctuary within it; Wular Lake (J&K UT) — largest freshwater lake in India; threatened by siltation and encroachment; Loktak Lake (Manipur) — largest freshwater lake in NE India; floating phumdi (biomass); Keibul Lamjao NP (world's only floating NP); Sangai deer habitat; Dal Lake (J&K UT) — threatened by eutrophication; Sambhar Lake (Rajasthan) — largest inland saltwater lake; flamingos; Vembanad-Kol (Kerala) — longest lake in India; Ramsar site; important for Nehru Trophy Boat Race region; Deepor Beel (Assam) — Ramsar site near Guwahati; elephant corridor. Wetlands Rules 2017 replace 2010 rules; State Wetland Authorities constituted for management. India has 85 Ramsar sites as of 2024.
Marine Biodiversity
India has a coastline of ~7,516.6 km with rich marine biodiversity. Important marine species: Dugong (sea cow) — found in Gulf of Mannar, Palk Bay, A&N Islands; endangered; Project Dugong launched; Whale Shark — largest fish; seasonally visits Gujarat coast (Saurashtra); protected under Schedule I; 5 species of marine turtles in India — Olive Ridley (mass nesting at Gahirmatha, Odisha), Green Turtle, Hawksbill, Leatherback, Loggerhead; all Schedule I. Marine Protected Areas (MPAs): Gulf of Mannar MNP, Mahatma Gandhi Marine NP (A&N), Gulf of Kutch MNP. India's EEZ (Exclusive Economic Zone): ~2.02 million sq km. Blue Economy Policy draft focuses on sustainable marine resource use. National Plan of Action for Sharks (NPOA-Sharks) addresses shark conservation. Marine pollution from microplastics, oil spills, sewage discharge threatens coastal ecosystems.
Invasive Alien Species
Invasive Alien Species (IAS) are the 2nd largest threat to biodiversity after habitat loss. Major IAS in India: (1) Lantana camara — most dominant invasive weed in Indian forests; from Central America; occupies 40% of Indian tiger range; suppresses native undergrowth; (2) Water Hyacinth (Eichhornia crassipes) — "Terror of Bengal"; blocks waterways, depletes dissolved oxygen; smothers native aquatic plants; (3) Prosopis juliflora (Vilayati babool/mesquite) — dominates arid/semi-arid areas of Rajasthan, Gujarat; invaded Banni grasslands; (4) Parthenium hysterophorus (Congress grass/gajar ghas) — causes severe respiratory allergies, skin dermatitis; reduces crop yields; (5) Mikania micrantha (mile-a-minute vine) — NE India; smothers native vegetation; (6) African catfish (Clarias gariepinus) — threatens native fish; (7) Pine trees in Shola grasslands — displace native grassland-shola mosaic in Nilgiris. Prevention through quarantine, early detection, and biological control (e.g., Zygogramma beetle for Parthenium) are key strategies.
Traditional Knowledge and Biodiversity
India has a rich tradition of biodiversity conservation embedded in cultural practices. Sacred Groves: community-protected forest patches with religious significance; over 13,000 documented in India; known as "Dev Vans" (HP), "Law Kyntang" (Meghalaya), "Kavu" (Kerala), "Sarna" (Jharkhand/Chhattisgarh), "Orans" (Rajasthan); harbour rare species not found elsewhere. Traditional Knowledge Digital Library (TKDL): database of 3.6 lakh formulations from Ayurveda, Siddha, Unani, Yoga; used to challenge biopiracy patents (e.g., neem, turmeric, Basmati rice patents challenged successfully). People's Biodiversity Registers (PBRs): documented by BMCs at panchayat level; record local biodiversity and traditional knowledge. India's National Biodiversity Targets (aligned with Aichi): 12 targets set in 2014 for 2020; now being revised for post-2020 GBF targets. Community conserved areas (CCAs): managed by indigenous/local communities — Bishnoi community (Rajasthan, protect wildlife especially blackbuck and khejri trees since 1730), Khasi Sacred Forests (Meghalaya).
Biodiversity and Ecosystem Services
Ecosystem services framework (Millennium Ecosystem Assessment, 2005): (1) Provisioning — food, water, timber, fibre, genetic resources, medicine (80% of rural India depends on traditional medicine from biodiversity); (2) Regulating — climate regulation, flood control, water purification, disease regulation, pollination (Rs 10,000 crore+ annually from pollination services); (3) Cultural — spiritual, recreational, aesthetic, educational (ecotourism revenue from tiger reserves alone >Rs 5,000 crore annually); (4) Supporting — nutrient cycling, soil formation, primary production, water cycling. Economics of biodiversity: TEEB (The Economics of Ecosystems and Biodiversity) study estimates global ecosystem services value at $125-145 trillion/year. India's forests provide ecosystem services worth ~Rs 7 lakh crore/year. Payment for Ecosystem Services (PES): compensating landholders for maintaining ecosystems; Costa Rica model studied for India. Dasgupta Review (2021): GDP must incorporate natural capital; biodiversity loss is an economic failure.
Biodiversity Monitoring and Assessment
Key monitoring mechanisms: (1) All India Tiger Estimation — every 4 years using camera traps, pugmarks, DNA analysis; 4th cycle (2022) estimated 3,682 tigers; M-STrIPES app used for monitoring; (2) Asian Elephant Census — 2017 estimated ~29,964; synchronized block count method; (3) Asian Waterbird Census (AWC) — annual; coordinated by Wetlands International; tracks migratory waterbird populations; (4) ISFR (India State of Forest Report) — biennial by FSI using satellite imagery; tracks forest cover, tree cover, mangrove cover; (5) Zoological Survey of India (ZSI, Kolkata) — records animal diversity; Fauna of India series; (6) Botanical Survey of India (BSI, Kolkata) — records plant diversity; Flora of India project; (7) Environmental DNA (eDNA) — emerging technique; detecting species from water/soil samples without direct sighting; used in rivers for Gangetic dolphin monitoring. India's Biodiversity Register at national level maintained by NBA.
Climate Change and Biodiversity
Climate change threatens biodiversity through: temperature rise (species shift ranges upward/poleward — Himalayan treeline shifting 5 m/decade; apple cultivation zone in HP moving higher), phenological changes (altered flowering/migration timings — early flowering of Rhododendrons in NE India disrupts pollinator cycles), coral bleaching (mass events in Gulf of Mannar and Lakshadweep linked to El Nino warming), sea-level rise (threatens coastal habitats — Sundarbans losing ~200 sq km over 20 years; Lakshadweep atolls vulnerable), ocean acidification (reduced calcification in marine organisms). IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) — the "IPCC for biodiversity" — estimates 1 million species face extinction without transformative change. India's INDC/NDC includes creating additional carbon sink of 2.5-3 billion tonnes of CO2 equivalent through additional forest and tree cover by 2030. Nature-based Solutions (NbS): using ecosystems to address climate and biodiversity challenges simultaneously.
Relevant Exams
Biodiversity is among the most high-yield topics for UPSC Prelims (2-4 questions yearly, often in environment section). Hotspot identification, endemic species-location matching, IUCN categories, and protected area counts are perennial favourites. SSC/RRB exams test national animal, national bird, national aquatic animal, and wildlife reserves. Current affairs on new Ramsar sites, tiger census results, and species discoveries appear regularly.