3.4.6 Biodiversity within a Community

Question 1

(Biodiversity within a Community) Define the term ‘biodiversity’.

Answer 1

Biodiversity is the number and variety of organisms in a different area.
The range and variety of genes, species and habitats in a particular region.

Question 2

(Biodiversity within a Community) Define the term ‘species diversity’.

Answer 2

The number of different species and the number of individuals of each species in a community.

Question 3

(Biodiversity within a Community) Define the term ‘genetic diversity’.

Answer 3

The variety of genes/alleles in a population.

Question 4

(Biodiversity within a Community) Define the term ‘ecosystem diversity’.

Answer 4

The range of different habitats.

Question 5

(Biodiversity within a Community) Define the term ‘species richness’.

Answer 5

The number of different species in a particular area at a given time.

Question 6

(Biodiversity within a Community) Define the term ‘species evenness’.

Answer 6

The number of organisms of each species in a particular area at a given time.

Question 7

(Biodiversity within a Community) Explain what the ‘index of diversity’ equation is.

Answer 7

Simpson’s Diversity Index (D) is a measure of the relationship between the number of different species in a habitat (species richness) and the number of individuals within each species (species evenness).

Question 8

(Biodiversity within a Community) Explain how farming techniques reduce biodiversity. (8)

Answer 8

1. Removal of hedgerows (to make more space)
2. Creating monocultures
3. FIlling in ponds/ draining marsh and other wetland
4. Overgrazing of land
5. Use of pesticides
6. Use of fertilisers
7. Escape of effluent from silage stores into watercourses - see next slide
8. Absence of crop rotation or intercropping

Question 9

(Biodiversity within a Community) Explaining the balance between conservation and farming. (11)

Answer 9

1. Maintain existing hedgerows.
2. Plant hedges rather than using fences as field boundaries (biodiversity corridors).
3. Maintain existing ponds and where possible create new ones.
4. Leave wet corners of fields rather than draining them.
5. Plant trees on land with a low species diversity rather than species-rich areas.
6. Reduce the use of pesticides - use biological control where possible or GM organisms that are resistant to pests.
7. Use organic fertilisers rather than inorganic ones.
8. Use crop rotation using a nitrogen-fixing crop rather than fertilisers to improve soil.
9. Use intercropping rather than herbicides to control weeds & pests.
10. Create natural meadows
11. Introduce conservation headlands