Biodiversity

Question 1

What is the species diversity index?

Answer 1

d = N(N-1) / Σ n(n-1)

d = species diversity index
N = organisms of all species
n = organisms of each species
Σ = sum of

Question 2

What is species richness?

Answer 2

• count the number of different species in an area
• species diversity is a better measure because it takes into account the number of organisms in each species and so is a better measure of biodiversity

Question 3

What is the impact of agriculture on biodiversity?

Answer 3

• farmers select more productive crops
• frequency of alleles is reduced
• crop yield needs to be large for economic reasons
• one area can only support a certain amount of biomass, little area left for anything else

Question 4

How else can biodiversity be reduced by farming?

Answer 4

• crops sprayed with pesticides and man-made fertiliser - further disadvantages and excludes species
• creating monocultures
• overgrazing land
• lack of crop rotation
• removing hedgerows and filling in ponds

Question 5

How can farmers increase species diversity?

Answer 5

• maintain hedgerows
• plant hedges instead of fences
• maintain and create ponds
• plant native trees on land with low species diversity
• reduce use of pesticides (use biological control or GM)
• use organic fertilisers
• introduce conservation headlands