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Biodiversity, Conservation and Environmental Issues — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYBiodiversity, Conservation and Environmental Issues5 Marks
Question
Species richness goes on decreasing as we move from equator to pole. Explain.
✓

Answer

  1. In tropical regions, there are lesser climatic changes throughout the year and availability of plenty of sunlight.
  2. Moreover, in tropical areas there are lesser disturbances like periodic glaciations as compared to those seen in the polar regions.
  3. In tropical regions, there is a stability over millions of years which favoured speciation and hence there is more species richness.
  4. Also in tropical regions, there are lesser migrations which reduce gene flow between geographically isolated regions. This too favoured speciation.
  5. There is more availability of intense sunlight, warmer temperatures and higher annual rainfall in tropics. These factors have brought higher species richness in tropics.
  6. Constant climatic conditions and abundance of resources in tropical regions provide more food preferences for animals species.
  7. E.g. fruits are available throughout the year in rain forests, therefore variety of frugivorous animals are seen here, as compared to the temperate regions.
    In short, species richness or diversity for plants and animals decreases as we move away from equator to the poles.

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