A-Level Biology AQA 7402

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.

An index of diversity describes the relationship between the number of species in a community and the number of individuals in each species.

Calculation of an index of diversity ($d$) from the formula

$d = \dfrac{N(N-1)}{\sum{n(n-1)}}$

where $N$ = total number of organisms of all species and $n$ = total number of organisms of each species.

Farming techniques reduce biodiversity. The balance between conservation and farming.