3.4.6 Biodiversity within a community

Question 1

What is biodiversity?

Answer 1

The variety of living organisms in an area.

Question 2

What is species richness?

Answer 2

The number of different species in a community.

Question 3

Give three ways in which agriculture can reduce biodiversity.

Answer 3

• Woodland clearance (or Hedgerow removal): Reduces the no. of trees and no. of different species. Destroys habitats, so some species could lose their shelter and food source.
• Pesticides: Reduces diversity by directly killing the pests. Any species that feed on the pests will lose a food source.
• Herbicides: Reduces plant diversity and the no. of organisms that feed on the weeds.
• Monoculture: A single type of plant reduces biodiversity directly. Supports fewer organisms, which further reduces biodiversity.

Question 4

What two things does an index of diversity take into account when measuring biodiversity?
[2 marks]

Answer 4

• The number of different species…

- …and the number of individuals/population size of each species in a community.