Wednesday, 5 March 2025

BIODIVERSITY AND CONSERVATION PART 1 CBSE XII

BIODIVERSITY AND CONSERVATION


1. BIODIVERSITY

  • Definition: Biodiversity refers to the variety of life forms (plants, animals, microorganisms) on Earth, including the ecosystems they form and the ecological processes they sustain.

  • Levels of Biodiversity:

    1. Genetic Diversity: Variation in genes within a species (e.g., different breeds of dogs).

    2. Species Diversity: Variety of species in a region (e.g., tigers, elephants, and deer in a forest).

    3. Ecological Diversity: Diversity of ecosystems (e.g., forests, deserts, wetlands).


2. GLOBAL BIODIVERSITY

  • Total Species: Approximately 8.7 million species exist on Earth, but only 1.2 million have been identified so far.

  • Distribution: Biodiversity is not evenly distributed. Tropical regions (e.g., Amazon rainforest) have the highest biodiversity due to favorable climate and resources.


3. IMPORTANCE OF BIODIVERSITY

  • Ecological Importance:

    • Maintains ecosystem balance.

    • Supports nutrient cycling, soil formation, and climate regulation.

  • Economic Importance:

    • Provides food, medicine, and raw materials (e.g., timber, fibers).

    • Supports industries like agriculture, pharmaceuticals, and tourism.

  • Ethical and Aesthetic Importance:

    • Every species has an intrinsic right to exist.

    • Adds beauty and cultural value to nature.


4. LOSS OF BIODIVERSITY

  • Causes of Biodiversity Loss:

    1. Habitat Destruction: Deforestation, urbanization, and industrialization.

    2. Overexploitation: Overharvesting of resources (e.g., hunting, fishing).

    3. Pollution: Air, water, and soil pollution harm species.

    4. Climate Change: Alters habitats and affects species survival.

    5. Invasive Species: Non-native species disrupt ecosystems (e.g., water hyacinth in Indian rivers).

  • Consequences of Biodiversity Loss:

    • Disruption of food chains and ecosystems.

    • Loss of potential medicinal and economic resources.

    • Increased vulnerability to natural disasters.


5. CONSERVATION OF BIODIVERSITY

  • Definition: Conservation refers to the protection, preservation, and sustainable management of biodiversity.

  • Types of Conservation:

    1. In-situ Conservation: Protecting species in their natural habitats.

      • Examples: National parks, wildlife sanctuaries, biosphere reserves.

      • Biosphere Reserves in India: Nilgiri, Sundarbans, Gulf of Mannar.

    2. Ex-situ Conservation: Protecting species outside their natural habitats.

      • Examples: Zoos, botanical gardens, seed banks, cryopreservation.

  • International Efforts:

    • Convention on Biological Diversity (CBD): A global agreement to conserve biodiversity.

    • IUCN Red List: Tracks the conservation status of species.

    • Project Tiger (1973): A conservation initiative in India to protect tigers.


6. BIODIVERSITY HOTSPOTS

  • Definition: Regions with high species richness and endemism (species found nowhere else) that are under threat.

  • Criteria for Hotspots:

    • Must have at least 1,500 endemic plant species.

    • Must have lost at least 70% of its original habitat.

  • Examples:

    • Western Ghats (India)

    • Himalayas

    • Amazon Rainforest

    • Madagascar


7. SUSTAINABLE DEVELOPMENT AND BIODIVERSITY

  • Sustainable Development: Meeting the needs of the present without compromising the ability of future generations to meet their own needs.

  • Role of Biodiversity in Sustainable Development:

    • Provides ecosystem services (e.g., clean air, water, fertile soil).

    • Supports livelihoods and economic growth.

  • Strategies for Sustainable Development:

    • Promote renewable energy.

    • Reduce waste and pollution.

    • Encourage eco-friendly practices.


8. IMPORTANT TERMS

  • Endemism: Species native to and found only in a specific region.

  • Extinction: Permanent loss of a species.

  • Keystone Species: Species that play a critical role in maintaining ecosystem balance (e.g., tigers, sea otters).

  • Ecosystem Services: Benefits provided by ecosystems to humans (e.g., pollination, water purification).

 

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BIODIVERSITY AND CONSERVATION PART 1 CBSE XII

BIODIVERSITY AND CONSERVATION 1. BIODIVERSITY Definition:  Biodiversity refers to the variety of life forms (plants, animals, microorganisms...