[Biology] Bio-diversity

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INTRODUCTION

  • The term Biodiversity comes from two words: ‘bio’ meaning life and ‘diversity’ means variability.
  • Biodiversity represents variety in all the living beings i.e. the different plants, animals, microorganisms along with all the genetic information they have and the ecosystem they form.

TYPES OF BIODIVERSITY

  • Biodiversity is usually explored at three levels, which work together and create complexity of life on earth. These include:
    • Genetic diversity
    • Species diversity
    • Ecosystem diversity

GENETIC DIVERSITY

  • Genetic diversity refers to the variety of genes within a species.
  • It encompasses the variety in type and number of genes and chromosomes present in various species.
  • Every individual of a species has its own genetic composition. It means that a species may have different populations, each with different genetic combinations.

EXAMPLES: There are more than 50,000 varieties of rice in India.

SPECIES DIVERSITY

  • Species diversity is defined as the number of species per unit area. It refers to the variety of species in a habitat and their relative abundance.

ECOSYSTEM/ ECOLOGICAL DIVERSITY

  • Ecological diversity refers to biotic communities, habitats and ecological processes occurring in the entire biosphere.
  • It is the largest scale of biodiversity, and within each ecosystem, there is both species and genetic diversity.

FOR EXAMPLE

  • The landscapes i.e. mountains, grasslands, deserts exhibit ecosystem diversity.

IMPORTANCE OF BIODIVERSITY

The maintenance of biodiversity is very necessary for sustaining life on earth. Some of the reasons why biodiversity is important are:

  • The ecosystem sustains the services without which humans cannot survive. A diverse ecosystem is more productive and is able to withstand environmental stress.
  • Biodiversity serves as a reservoir of resources for the manufacture of food, cosmetics and pharmaceuticals.
  • Wild plants such as Cinchona are used for medicinal purposes.
  • The national parks and sanctuaries provide a source of recreation and tourism. They are a source of beauty and joy for people.

ROLE OF BIODIVERSITY

  • Biodiversity gives stability to the ecosystem and maintains the ecological balance. Different species in the ecosystem are linked to each other through food chains and food webs. The loss of one species affects the survival of other species. Thus, the ecosystem becomes fragile.
  • Forests with diverse groups of plant species are the major sinks of carbon dioxide which is a greenhouse gas causing global warming, thus biologically diverse forests help in reducing global warming.
  • Biodiversity protects the water resources. Vegetation facilitates the percolation of water into the soil, thus helping in maintenance of the ground water table.

THREATS TO BIODIVERSITY

  • The major threat to biodiversity, according to Edward Wilson, is HIPPO. HIPPO stands for:
    • Habitat destruction
    • Climate change
    • Invasive species
    • Pollution
    • Human overpopulation
    • Over-harvesting

HABITAT LOSS AND DEGRADATION

  • Habitat loss refers to changes in the ecosystem that result in the development of a non-viable habitat.
  • Such a habitat can no longer support the organisms present, thus leading to a decline in their population.

CLIMATE CHANGE

  • It is the long term and irreversible change that occurs in the Earth’s climate.
  • The increase in the temperature of the atmosphere has some major effects on our environment such as the seasons, rising sea levels, and glacial retreats.

POLLUTION

  • All forms of pollution are a threat to all life forms on Earth. However, it imposes a major threat to biodiversity when it comes to the nutrient reloading of the elements; nitrogen and phosphorus.

OVEREXPLOITATION

  • Overexploitation means overharvesting species at rates faster than they can sustain themselves in the wild. Because of this, the species population is put into risk of extinction.

HUMAN OVERPOPULATION

  • With the rapid increase in human population, natural habitats are being lost and human indulgence in bio-diversity is increasing.

CONSERVATION OF BIODIVERSITY

  • Conservation of biodiversity refers to the protection, restoration and management of biodiversity to derive sustainable benefits for present and future generations.

STRATEGIES FOR CONSERVATION OF BIODIVERSITY

  • Biodiversity can be conserved by reversing the decline of species. We need to restore the population of declined species.
  • The conservation of all biological aspects covers and conserves food, livestock, microbes, agriculture including plants and animals.
  • Deforestation can be preserved by every means.
  • Poaching and killing wild animals must be prohibited.
  • Public awareness must be provided about biodiversity and its conservation.

REFERENCES

  • Arihant’s handbook of Biology. The Living World. Page no: 1-6.
  • NCERT Biology; Textbook for Class 11. The Living World. Page no: 1-62.
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