NCERT Class 11 Geography Chapter 16: Biodiversity and conservation YouTube Lecture Handouts

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NCERT Class 11 Geography Chapter 16: Biodiversity and Conservation

Why Biodiversity?

  • Result of 2.5-3 million years of evolution

  • Number of species vary from 2 million to 100 million

  • Constantly evolving

  • Average half-life of species is 1 to 4 million years & 99% species that lived are now extinct

  • More diversity is seen in tropics

  • Variability within and between species and ecosystem

Types of Biodiversity

  • Genetic Diversity – building blocks and variations of genes within species (similar physical characteristics) – required for healthy breeding

  • Species Diversity – variety of species and hotspots

  • Ecosystem Diversity – diversity of habitats and ecological processes

Importance of Biodiversity

  • Ecological Role – capture and store energy and decompose materials, cycle water and nutrients, fix gases, regulate climate, more productive; Higher variety of species, higher is the stability of ecosystem

  • Economic Role – agro, crop, cosmetics, pharma, livestock, medicinal

  • Scientific Role – how species evolve, functions, role of species

Loss of Biodiversity

  • Growth in population

  • Higher consumption of natural resources

  • Tropical regions – ΒΌ area with ΒΎ population (50% species)

  • Earthquake

  • Floods

  • Volcano

  • Forest fires

  • Pesticides

  • Pollutants

  • Exotic species – species that are not naturally found

IUCN (Threatened Species and Conservation)

  • Vulnerable Species

  • Endangered – Red Data List (red panda)

  • Critically Endangered – Zenkeria Sebastinei (grass in Agasthayamalai)

  • Rare Species – less population (Humbodtia decurrens Bedd – endemic in SW Ghats)

Conservation of Biodiversity

  • Sustainable use of resources

  • Cooperation of community

  • Development of institutional communities

  • Convention of Biodiversity (Earth Summit, 1992)

  • Wildlife Protection Act, 1972 (National parks, sanctuaries and biosphere reserves)

  • CBD Steps:

  • Preserve species

  • Prevent extinction

  • Variety of trees

  • Identify habitats

  • Safeguard habitat

  • Regulate trade of plants and animals

Biodiversity Hotspots – 12 Centers

Biodiversity hotspots

Biodiversity Hotspots

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  • Hotspots based on vegetation, primary productivity, rich in food, fodder, timber

  • 85% species of Madagascar are not found anywhere else (poorest people with slash and burn cultivation)

  • Hawaii has unique species but threatened due to introductory species.