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 – area with 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
  • 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.

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