3.4.6 Biodiversity + 3.4.7 Investigating Diversity

biodiversity

the variety of living organisms

-stability of ecosystems

3 components of biodiversity

-species diversity

-genetic diversity

-ecosystem diversity

species richness

a measure of the number of different species in a community

index of diversity

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

index of diversity EQUATION

d = N(N-1) / sum of n(n-1)

N - total number of organisms of all species

n - total number of organisms of each species

-the higher the index, the more diverse the area

impacts of agriculture -biodiversity

reduces it

-farmland is typically used for only 1 species = monoculture

-use of pesticides

-removal of hedgerows

impacts of agriculture -species diversity

decreases it

-the few species that possess desirable qualities are selected and bred, other species are excluded by culling or pesticides so many individuals of few species

impacts of agriculture -genetic diversity

decreases it

-farmers select for certain characteristics so reduces number of different alleles

techniques to reduce impact of agriculture

-maintain hedgerows

-limit use of pesticides

-maintain ponds

-crop rotation

ways to compare genetic diversity

-the frequency of measurable/observable characteristics

-the base sequence of DNA

-the base sequence of mRNA

-the amino acid sequence of the proteins encoded

random sampling method

1) mark out grid of known area

2) random number generator for coordinates

3) place quadrat at coordinates

4) use large number of quadrats selected at random

5) measure number of species in each quadrat

6) repeats + large sample size = representative

7) use mean number = total number or % / number of quadrats or total size = mean number x number of quadrats