Biodiversity Flashcards
1
Q
What is the species diversity index?
A
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
2
Q
What is species richness?
A
- 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
3
Q
What is the impact of agriculture on biodiversity?
A
- 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
4
Q
How else can biodiversity be reduced by farming?
A
- 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
5
Q
How can farmers increase species diversity?
A
- 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