The combination of species richness and species evenness give an indication of biodiversity.Simpson's index of diversity takes into account both species richness and species evenness.It is calculated using the formula:
Σ means the sum of D is the index of diversity n is the number of individuals of a particular species N is the number of individuals of all speciesSimpsons index of diversity is a number between 0 and 1. An index of zero means no diversity and an index of 1 means infinite diversity.Low diversity ecosystems tend to be in extreme environments. Species in these environments are highly adapted to survive in these extreme conditions and may be unable to survive elsewhere.
| D = 1 - | Σ( | n N | ) | ² |