3.4.6 - Biodiversity within a community

Question 1

Define species diversity

Answer 1

number of different species and number of individuals of a species in a community

Question 2

Define genetic diversity

Answer 2

number of different alleles of genes in a population

Question 3

Define ecosystem diversity

Answer 3

range of habitats

Question 4

Define species richness

Answer 4

measure of the number of different species in
a community

Question 5

Why is it useful to calculate species diversity index?

Answer 5

measure both the number of different species and the number of individuals of a species
so takes into account species only present in small numbers/relative proportion of each species

Question 6

What does it mean if you get a high value for the species diversity index?

Answer 6

more diverse

Question 7

What is the influence of agriculture on species diversity?

Answer 7

growing crops reduces the variety of plants present
- which reduces the variety of food source
- and the variety of habitats (less land available for other species)
- reducing the variety of species able to survive in that area - increased competition for space and resources

Question 8

Define natural and agricultural ecosystems - what are the issues with agricultural ecosystem?

Answer 8

• natural - complex communities with a high species diversity index
• agricultural - species selected which contain alleles for a desired trait - reduced genetic variety - other species have to compete for light and space - pesticides remove these species further - species diversity is very low

Question 9

Why does there need to be a balance between conservation and farming?

Answer 9

we need to increase species and habitat diversity without raising food costs of lowering yields

Question 10

Conservation techniques to improve species diversity in farming

Answer 10

• maintain hedges
• reduce pesticides - use biological control
• use organic fertilisers
• create meadows and use hay instead of grasses for silage