3.4.6 biodiversity within a community Flashcards
1
Q
define biodiversity
A
the variety of living organisms and ecosystems on Earth
2
Q
define species richness
A
a measure of the number of different species in a community
3
Q
what does an index of diversity show?
A
the relationship between the number of species in a community and the number of individuals in each species
4
Q
how do you calculate index of diversity?
A
d = N(N-1)/ sum of n(n-1)
5
Q
what is the effect of deforestation?
A
- destroys habitats
- some animal species lose their food source
- some animal species lose their shelter
- these species may die or have to migrate to another suitable area
6
Q
what is the effect of agriculture on species diversity?
A
- woodland clearance = reduces diversity
- hedgerow removal = reduces diversity
- pesticides = reduces diversity by directly removing food source of some organisms
7
Q
what are the benefits of deforestation?
A
- wood and land for homes to be built
- local areas become more developed by attracting businesses
8
Q
what are the risks of deforestation?
A
- diversity is reduced species could become extinct
- less carbon dioxide is stored because there are fewer plants and trees
- many medicines come from organisms found in rainforests possible future discoveries may be lost
9
Q
what are the benefits of agriculture?
A
- more food can be produced
- food is cheaper to produce so food prices are lower
- local areas become more developed by attracting businesses
10
Q
what are the risks of agriculture?
A
- diversity is reduced
- natural beauty is lost
