The Concept of Biodiversity

Biodiversity is a contraction of ‘biological diversity’ and refers to the variety of life on Earth and the myriad of processes associated with it. It includes all life forms, from unicellular fungi, protozoa, and bacteria to complex multicellular organisms such as plants, birds, fishes, and mammals. According to the World Resources Institute, biodiversity is the variety of the world’s organisms, including their genetic diversity and the assemblages they form. It serves as the foundation for human life and well-being by linking genes, species, and ecosystems.

Since biodiversity encompasses various aspects, it is commonly studied at three hierarchical levels:

1. Genetic Diversity

Genetic diversity refers to the diversity of genes within a species. There is genetic variability among populations and individuals of the same species. Within a species, several varieties, strains, or races may differ in characteristics such as size, shape, disease resistance, pest resistance, and resilience to adverse environmental conditions. This genetic makeup influences the species’ adaptability and evolution.

Heritable variation plays a crucial role in natural and artificial selection, ultimately forming the basis of biodiversity. Genetic diversity is essential for evolutionary changes, species survival, and the formation of new species. Various applications of biotechnology, such as crop and animal breed improvement, rely on genetic diversity to identify and incorporate desirable traits.

2. Species Diversity

Species diversity refers to the number of species of plants and animals present in a region. It is not just about counting species but also understanding their relative abundance. A community where all species have equal numbers is more diverse than one dominated by a single species. Additionally, species that differ significantly from each other contribute more to overall biodiversity than similar species.

3. Ecosystem Diversity

Ecosystem diversity refers to the diversity at a higher level of organization, encompassing different ecosystem types at a global or continental scale. It is assessed based on species diversity within ecosystems and the unique interactions between species and their physical environment. An ecosystem with species present in nearly equal abundance is considered more diverse than one with extremes of high and low abundance.

4. Landscape Diversity Landscape diversity is sometimes used on a broad regional scale. It refers to the size and distribution of multiple ecosystems and their interactions across a given land surface.

Biogeographic Zones of India

India is exceptionally rich in biodiversity, representing almost all major biogeographic zones of the world. According to the Wildlife Institute of India, the country’s biological wealth is classified into ten broad biogeographic zones, each characterized by distinct flora and fauna and climatic conditions.

1. Trans-Himalayan Zone

• Covers about 1,86,000 sq. km.
• Sparse mountain vegetation.
• Rich in wild sheep and goat species.
• Home to the snow leopard and the migratory black-necked crane.

2. Himalayan Zone

• Extends from Kashmir to the North East Frontier Area (NEFA), covering approximately 3,47,000 sq. km.
• Four biotic provinces: North-West, West, Central, and East Himalayas.
• Three altitudinal vegetation zones:
  1. Sub-montane or lower region (tropical and subtropical): Includes trees like Acacia catechu, Cedrela toona, Eugenia jambolana, Albizzia procera.
  2. Temperate or montane zone (5,500 – 12,000 ft.): Dominated by Pinus excelsa, Cedrus deodara, Abies pindrow, Picea morinda, Juniperus, Taxus baccata.
  3. Alpine zone (above 12,000 ft.): Marks the tree line; shrubs like Betula utilis, Juniperus, and Rhododendron grow in grassy areas. Above 15,000 ft., plant growth is minimal due to the snow line.

India’s biogeographic diversity plays a crucial role in sustaining ecological balance and providing valuable resources for various industries and human livelihood. Conservation efforts are essential to maintaining this biodiversity for future generations.

Ecological Zones of India

1. Desert Zone

The desert zone comprises three biotic provinces: Kutch, Thar, and Ladakh.

North-West Desert Region (Kutch and Thar)

• Covers an area of approximately 2,25,000 sq. km.
• Includes parts of Gujarat, Rajasthan, Haryana, and Delhi.
• Climate:
  • Very hot and dry summers.
  • Cold winters.
  • Rainfall is less than 700 mm.
• Vegetation:
  • Extensive grasslands with xerophytic plants.
  • Common species:
    • Acacia nilotica, Prosopis spicifera (trees).
    • Calotropis, Eleusine, Panicum antidotale (ground vegetation).
• Wildlife:
  • Home to the Great Indian Bustard, a highly endangered species.

Ladakh Region

• A cold desert with sparse vegetation.

2. Semi-Arid Zone

• Located adjacent to the north-west desert region.
• Includes parts of Madhya Pradesh, Chhattisgarh, Odisha, and Gujarat.
• Covers an area of 5 lakh sq. km.
• Climate & Vegetation:
  • Rainfall influences thorny, mixed deciduous, and sal forests.
  • Common tree species:
    • Tectona grandis (Teak), Diospyros melanoxylon, Butea monosperma.
  • Thorny vegetation includes:
    • Acacia leucophloea, Acacia catechu.

3. Western Ghats Zone

• Extends from Gujarat (north) to Cape Comorin (south).
• Covers an area of 1.6 lakh sq. km.
• Climate:
  • Heavy rainfall.
• Vegetation:
  • Tropical moist evergreen forests.
  • Sub-tropical/temperate evergreen forests.
  • Mixed deciduous forests.
  • Mangrove forests.

4. Deccan Peninsular Zone

• Comprises five biotic provinces:
  • Deccan Plateau (South)
  • Central Plateau
  • Eastern Plateau
  • Chhota Nagpur Plateau
  • Central Highlands
• Covers 14 lakh sq. km.
• Climate:
  • Semi-arid region (rain-shadow of Western Ghats).
  • Receives about 100 mm of rainfall.
• Vegetation:
  • Forests of:
    • Boswellia serrata, Hardwickia pinnata, Tectona grandis.

5. The Gangetic Plain

• Extends up to the Himalayan foothills.
• Includes Uttar Pradesh, Bihar, and West Bengal.
• Covers 3.5 lakh sq. km.
• Climate:
  • Rainfall varies from less than 700 mm (Western UP) to more than 1,500 mm (West Bengal).
• Vegetation:
  • Tropical moist and dry deciduous forests.

6. North-East India

• One of the richest floral regions of India.
• Covers 1.6 lakh sq. km.
• Climate:
  • Receives heaviest rainfall (Cherrapunji: more than 10,000 mm).
  • High temperature and humidity.
• Vegetation:
  • Dense tropical evergreen forests.
  • Common species:
    • Mesua ferrea, Michelia champaca, Dipterocarpus macrocarpus.
    • Several Bamboo species and insectivorous plants.
• Agricultural Significance:
  • Wild relatives of cultivated plants such as banana, mango, citrus, and pepper.

7. The Islands

• Includes Lakshadweep (Arabian Sea) and Andaman & Nicobar Islands (Bay of Bengal).
• Vegetation:
  • Coastal mangroves, beach forests, and evergreen forests.
  • Common species:
    • Rhizophora, Calophyllum, Dipterocarpus.

8. Coastal Region

• India has a 7,516.5 km long coastline.
• Vegetation:
  • Mangrove forests dominate estuarine regions.
  • Notable mangrove sites:
    • Pichavaram (Tamil Nadu).
    • Ratnagiri (Maharashtra).

Conservation of Biodiversity

In-Situ Conservation (On-Site Conservation)

This involves protecting species in their natural habitats. Major strategies include:

• Biosphere Reserves: Large areas for conservation of flora, fauna, and indigenous communities.
• National Parks: Protected areas focusing on ecosystem conservation and public enjoyment.
• Wildlife Sanctuaries: Areas for protecting wildlife with limited human interference.
• Sacred Groves: Community-protected forest areas with religious and cultural significance.

Ex-Situ Conservation (Off-Site Conservation)

This involves conserving biodiversity outside natural habitats. Methods include:

• Botanical Gardens: Preserve plant species and conduct research.
• Zoological Parks: Maintain and breed endangered species.
• Seed Banks: Store seeds of rare and endangered plants.
• Gene Banks: Preserve genetic material (seeds, embryos, DNA) for future use.
• Cryopreservation: Freezing genetic material for long-term conservation.

International and National Efforts for Biodiversity Conservation

International Initiatives

1. Convention on Biological Diversity (CBD): A global treaty for sustainable biodiversity use.
2. Ramsar Convention: Conservation of wetlands of international importance.
3. CITES (Convention on International Trade in Endangered Species): Regulates trade in wildlife species.
4. IUCN (International Union for Conservation of Nature): Maintains the Red List of Threatened Species.
5. Biosphere Reserves Program (UNESCO): Promotes conservation of landscapes and ecosystems.

National Efforts (India)

1. National Biodiversity Authority (NBA): Regulates biodiversity conservation and sustainable use.
2. Wildlife Protection Act (1972): Provides legal protection to endangered species.
3. Environmental Protection Act (1986): Regulates pollution and environmental conservation.
4. Project Tiger (1973): Focuses on tiger conservation.
5. Project Elephant (1992): Aims at elephant conservation and habitat protection.
6. Biodiversity Act (2002): Promotes conservation, sustainable use, and benefit-sharing of biodiversity resources.
7. Eco-Sensitive Zones: Areas near national parks and sanctuaries with restricted development activities.

Role of Communities in Biodiversity Conservation

• Joint Forest Management (JFM): Involves local communities in forest protection.
• Chipko Movement: Grassroots effort in India to prevent deforestation.
• Community Forest Reserves: Protect local biodiversity through traditional knowledge.
• Sacred Groves: Community-protected areas with high conservation value.