Topic 3: Biodiversity and conservation - ESS

List the three components of biodiversity. (3 marks)

Habitat diversity, species diversity, genetic diversity

Other than a low number of different species in an ecosystem, state one factor that indicates low ecosystem biodiversity. (1 mark)

Loss of habitat

From a conservation perspective, briefly explain why it is useful to calculate numerical values of species diversity for different biological communities. (2 marks)

Helps monitor changes in biodiversity over time and highlights areas where biodiversity is declining.

Briefly explain how the species diversity of a given area may be calculated. (3 marks)

Use a transect to collect data on the number of species. Species diversity can then be calculated using Simpson’s diversity index.

Explain the non-human factors contributing to the overall biodiversity of an ecosystem. (4 marks)

Biodiversity includes the diversity of species, habitats, and genes within an ecosystem. Species diversity refers to the number of different species present and their relative abundance. Habitat diversity refers to the variety of distinct habitats within an ecosystem. Genetic diversity refers to the variety of genetic material within populations.

Compare and contrast species diversity and species richness. (2 marks)

Both species richness and species diversity provide an estimate of the number of different species in an ecosystem. However, species diversity considers the abundance of species, whereas species richness does not.

In recent years, farmers have merged grazing fields together by removing hedgerows. This has resulted in a decline in the diversity of farmland birds. Explain why. (2 marks)

The removal of hedgerows results in the removal of species, as there are fewer food source.

Organic farms do not use any chemical insecticides. Suggest what effect organic farming would have on the number of farmland birds. (2 marks)

Organic farming would increase the number of farmland birds as there would be more insects available for the birds to feed on.