Biodiversity
Subject: General Science — Technology & Environment | Topic: Biodiversity Exam: AP Group 2 (APPSC) | Sources: NCERT Class XII, Shankar IAS, Lucent's GS
Introduction
Biodiversity covers hotspots, conservation strategies, wildlife protection, and threatened species. APPSC loves AP-specific biodiversity facts (Coringa, Nagarjunasagar-Srisailam), India's four hotspots, and Project Tiger statistics. Expect 2-3 questions.
Biodiversity Basics
- Three levels: Genetic (variation within species), Species (variety of species), Ecosystem (variety of ecosystems).
- Edward O. Wilson: "Father of Biodiversity."
- Estimated 8.7 million species on Earth; only ~1.7 million catalogued.
- India: 2.4% of world's land but 7-8% of global biodiversity — a megadiversity country.
Biodiversity Hotspots
Criteria (Norman Myers, 1988): ≥1,500 endemic vascular plants AND ≥70% original habitat lost.
Currently 36 hotspots worldwide covering 2.5% of land but supporting 50% of plant species.
India's 4 Hotspots
| Hotspot | Key Species |
|---|---|
| Western Ghats | One of 8 "hottest"; Lion-tailed macaque, Nilgiri tahr |
| Eastern Himalayas | Snow leopard, Red panda, orchids |
| Indo-Burma (incl. NE India) | Hoolock gibbon (India's only ape) |
| Sundaland (incl. Nicobar Islands) | Nicobar megapode, Nicobar pigeon |
Species Classification
| Type | Definition | Example |
|---|---|---|
| Endemic | Found only in one area | Asiatic lion (Gir), Nilgiri tahr |
| Exotic/Invasive | Introduced from other regions | Water hyacinth ("Terror of Bengal"), Lantana |
| Keystone | Disproportionately large impact | Elephants, fig trees |
| Indicator | Health of ecosystem | Lichens (air quality) |
| Flagship | Charismatic, garner public support | Tiger, Giant panda |
Threats to Biodiversity (HIPPO)
Habitat loss | Invasive species | Pollution | Population growth | Over-exploitation
- Current extinction rate: 100-1000× natural rate. Sixth Mass Extinction (Anthropocene).
- Marine plastic: ~8 million tonnes/year enter oceans.
Conservation Strategies
In-situ (Natural Habitat)
| Category | Features | India Total |
|---|---|---|
| National Parks | Strictly protected; no human activity | 106 |
| Wildlife Sanctuaries | Some human activities allowed | 573 |
| Biosphere Reserves | Core + buffer + transition zones | 18 |
Ex-situ (Outside Habitat)
- Zoos, Botanical gardens, Seed banks, Gene banks, Cryopreservation.
- Svalbard Global Seed Vault (Norway): "Doomsday vault."
Wildlife Protection in India
| Project | Year | Details |
|---|---|---|
| Wildlife Protection Act | 1972 | Schedules I-V; framework for NPs and sanctuaries |
| Project Tiger | 1973 | 55 reserves; population ~3,682 (2022); India has ~75% world's wild tigers |
| Project Elephant | 1992 | 32 reserves |
| Project Snow Leopard | 2009 | High-altitude conservation |
IUCN Red List Categories
EX (Extinct) → EW (Extinct in Wild) → CR (Critically Endangered) → EN (Endangered) → VU (Vulnerable) → NT (Near Threatened) → LC (Least Concern)
India examples: Bengal tiger (EN), Asiatic lion (EN), Indian rhinoceros (VU), Great Indian bustard (CR), Indian pangolin (EN).
Forests of India
| Type | Rainfall | Features |
|---|---|---|
| Tropical Evergreen | >200 cm | Dense, tall; Western Ghats, NE India |
| Tropical Deciduous | 70-200 cm | Most widespread; teak, sal, sandalwood |
| Mangrove | Coastal/tidal | Sundarbans (largest), Coringa (AP). Breathing roots (pneumatophores) |
India's forest cover: ~21.7%. Target: 33% (National Forest Policy, 1988).
Jim Corbett NP: India's first national park (1936) and first tiger reserve. Kaziranga NP: One-horned rhinoceros (UNESCO WHS). Gir NP: Only home of Asiatic lion.
AP-Specific Biodiversity
| Protected Area | Key Facts |
|---|---|
| Nagarjunasagar-Srisailam TR | Largest tiger reserve in India (~3,728 sq km); Nallamala Hills; Krishna River |
| Coringa WLS | 2nd largest mangrove; Godavari delta; fishing cat, olive ridley turtles, 200+ bird species |
| Sri Venkateswara NP | Near Tirupati; Indian giant squirrel, slender loris |
| Papikonda NP | Godavari River; primate conservation |
| Kolleru Lake | Ramsar site; migratory birds (pelicans, painted storks) |
| Pulicat Lake | 2nd largest brackish lagoon in India; flamingos |
Threatened in AP: Great Indian bustard (functionally extinct at Rollapadu), Jerdon's courser (critically endangered, Lankamalai).
Likely Exam Questions
-
How many biodiversity hotspots does India have? Ans: 4 (Western Ghats, Eastern Himalayas, Indo-Burma, Sundaland)
-
The largest tiger reserve in India by area is: Ans: Nagarjunasagar-Srisailam Tiger Reserve (AP)
-
India's first national park is: Ans: Jim Corbett National Park (1936, Uttarakhand)
-
India has approximately what percentage of the world's wild tigers? Ans: ~75%
-
The IUCN Red List category for Bengal tiger is: Ans: Endangered (EN)
-
The only home of the Asiatic lion is: Ans: Gir National Park, Gujarat
-
Coringa Wildlife Sanctuary is located in: Ans: Godavari delta, East Godavari district, AP
-
The criteria for a biodiversity hotspot include at least ___ endemic plant species: Ans: 1,500
-
India's target for forest cover is: Ans: 33% (National Forest Policy, 1988)
-
Pulicat Lake is famous for: Ans: Flamingos (2nd largest brackish water lagoon in India)