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Genetic information, variation and relationships between organisms
(AQA AS Biology) PART 5 of 6 TOPICS
Biodiversity within a community:
Biodiversity can relate to a range of habitats, from a small local habitat to the Earth.
Species richness is a measure of the number of different species in a community known as index of
N(N-1) / n(n-1) = index of diversity where
N = total number of individuals
n = total number of organisms in a species
Framers cut shrubs, bushes and hedges to increase the farm land. However it reduces the number of
habitats and the amount of food sources therefore reducing the biodiversity. Deforestation creates
the same effect but also decreases the amount of rainfall meaning crops and plants will have less
transpiration by photosynthesis, leads to soil erosion as the exposed soil can dry out and the nutrients
from the trees are not sent back into the soil, serious flooding can occur as the rainwater will not be
soaked and there will be an increase in the levels of CO2.
Conservation allows the number of reduced species to increase without destroying habitats and using
pesticides. This is so biodiversity can increase. The process of using pesticides and removing hedge
grows is done in a yearly cycle.
] That's all that you need to know for biodiversity within a community at AQA [