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Geography: Class 112 — Chapter 14: Biodiversity and Conservation

Introduction to Biodiversity

The term Biodiversity is a combination of two words: Bio (life) and diversity (variety). It refers to the number and variety of organisms found within a specified geographic region, encompassing plants, animals, micro-organisms, their genes, and the ecosystems they form.

Biodiversity is the result of 2.5 to 3.5 billion years of evolution. It is not distributed evenly on Earth; it is consistently richer in the tropics and decreases progressively towards the polar regions.

Levels of Biodiversity

Biodiversity can be classified and discussed at three distinct levels:

1. Genetic Diversity

Genetic Diversity refers to the variation of genes within species. Genes are the basic building blocks of life. This diversity is essential for the healthy breeding of populations. For example, human beings belong to the single species Homo sapiens but show vast physical variations due to genetic diversity.

2. Species Diversity

Species Diversity refers to the variety of species within a defined area. It is measured through species richness, abundance, and types. Areas with exceptionally high species diversity are known as hotspots of diversity.

3. Ecosystem Diversity

Ecosystem Diversity refers to the variety of habitats, biotic communities, and ecological processes occurring within different ecosystem types. Demarcating ecosystem boundaries is highly complex as their boundaries are not rigidly defined.

Importance of Biodiversity

Biodiversity plays critical roles across ecological, economic, and scientific dimensions:

Ecological Role

Every organism in an ecosystem performs specific functions that contribute to systemic stability:

  • Capture and storage of energy.
  • Production and decomposition of organic material.
  • Cycling of water and nutrients throughout the ecosystem.
  • Fixation of atmospheric gases and climate regulation.

A highly diverse ecosystem has a greater capacity to adapt to environmental changes and maintain stability.

Economic Role

Biodiversity serves as a reservoir of resources for daily human life, often referred to as agro-biodiversity or crop diversity. Key economic commodities include:

  • Food crops and livestock.
  • Forestry products and timber.
  • Fish and marine resources.
  • Medicinal resources and pharmaceutical ingredients.

Scientific Role

Biodiversity provides critical clues about the evolution of life. Each species helps scientists understand how life functions and how ecosystems are sustained.

Loss of Biodiversity

In recent decades, rapid human population growth and increased resource consumption have accelerated the loss of species and habitats globally.

Major Causes of Depletion

  • Habitat Destruction: Deforestation in species-rich tropical rainforests (which contain 50% of Earth's species) to meet human demands.
  • Natural Calamities: Earthquakes, floods, volcanic eruptions, forest fires, and droughts.
  • Pollution: Pesticides, hydrocarbons, and toxic heavy metals that destroy sensitive species.
  • Exotic Species: Introduction of non-native exotic species that disrupt local biotic communities.
  • Poaching: Merciless hunting of animals (e.g., tigers, elephants, rhinoceros) for commercial trade of horns, tusks, and hides.
IUCN Classification of Threatened Species

The International Union for Conservation of Nature and Natural Resources (IUCN) classifies threatened species into three major categories:

CategoryDescription
Endangered SpeciesSpecies in immediate danger of extinction. Information is published globally in the Red List.
Vulnerable SpeciesSpecies likely to enter the endangered category in the near future if threatening factors continue.
Rare SpeciesSpecies with very small global populations, confined to limited areas or thinly scattered.
Conservation of Biodiversity

Biodiversity conservation is vital for human survival. The Government of India and 155 other nations signed the Convention of Biodiversity at the Earth Summit in Rio de Janeiro, Brazil, in June 1992.

World Conservation Strategy Steps

  1. Preserve endangered species.
  2. Prevent extinction through proper planning and management.
  3. Preserve varieties of food crops, forage plants, timber trees, livestock, and wild relatives.
  4. Protect habitats where species feed, breed, rest, and nurse their young.
  5. Regulate international trade in wild plants and animals.

Conservation Initiatives in India

To protect and propagate species, India passed the Wild Life (Protection) Act, 1972, establishing national parks, sanctuaries, and biosphere reserves.

Mega Diversity Centres & Hotspots

There are 12 mega diversity centres located in tropical regions, including Mexico, Colombia, Ecuador, Peru, Brazil, Democratic Republic of Congo, Madagascar, China, India, Malaysia, Indonesia, and Australia.

Biodiversity Hotspots are identified by the IUCN based on their vegetation and primary productivity, focusing resources on highly vulnerable, species-rich ecosystems.