3.4.6 biodiversity within a community

Question 1

Biodiversity

Answer 1

Variety of living organisms in an area

3 components

1. Species diversity - the number of different species and the number of individuals of each species within a community
2. Genetic diversity
3. Ecosystem diversity

Question 2

Habitat

Community

Answer 2

Place where an organism lives

All the populations of different species in a habitat

Question 3

Local biodiversity

Global biodiversity

Answer 3

Variety of species in a small habitat e.g. pond/meadow

Variety of species living on earth

Question 4

Species richness

Answer 4

Number of different species in a community

Question 5

Index of diversity

Answer 5

Describes the relationship between the number of species in a community and the number of individuals in each species

The greater the species richness and species evenness, the higher the number

Question 6

Index of diversity v species richness

Answer 6

Index of diversity is a more useful measure of species diversity than species richness

• measures the number of individuals in a species & number of species
• takes into account the fact that some species may be present in high/low numbers

Question 7

How farming techniques reduce biodiversity

Answer 7

Removal of woodland and hedgerows

Monoculture e.g. replace natural meadows with one cereal crop

Use of pesticides, herbicides and inorganic fertilisers

Crops better competitions for resources e.g. light/nutrients

Question 8

Balance between conservation and farming

Answer 8

Humans need to make a balanced judgement between the demands for increased food production due to rapidly growing human population, and the need to conserve the environment

Some conservation techniques can be applied that increase biodiversity without raising food costs or lowering yields

• use of crop rotation of nitrogen fixing crops instead of fertilisers
• maintain existing hedgerows and plant new hedges instead of using fences
• reduce use of pesticides

Practices will make food slightly more expensive to produce, so to encourage farmers, offer incentives
- e.g. from Department for Environment, DEFRA and EU