Components of biodiversity are

• genetic diversity

  Genetic diversity is the number and frequency of all the alleles within a population.

  If one population of a species dies out then the species may have lost some of its genetic diversity, and this may limit its ability to adapt to changing conditions.

• species diversity

  Species diversity comprises

  • the species richness → the number of different species in an ecosystem

  • the relative abundance → the proportion of each species in the ecosystem

    → A community with a dominant species has a lower species diversity than one with the same species richness but no particularly dominant species.

• ecosystem diversity.

  Ecosystem diversity refers to the number of distinct ecosystems within a defined area.