An index of diversity describes the relationship between the number of species and the number of individuals in a community. Calculation of an index of diversity from the formula. Candidates should be able to • calculate the index of diversity from suitable data • interpret data relating to the effects of human activity on species diversity and be able to evaluate associated benefits and risks • discuss the ways in which society uses science to inform the making of decisions relating to biodiversity.

The index of diversity is a way of quantifying species diversity.

The formula is as follows (this will be given in an exam):

sciencebitz

where N= total number of organisms of all species (community)
and n= total number of organisms of each species

This means that, if we take a quadrant from a rain forest and we see one tree, five birds, twenty ants and two snakes the equation will be as follows:

1+5+20+2(1+5+20+2-1)                  
(1(1-1))+(5(5-1))+(20(20-1)+(2(2-1)
=
28(27)                          
1(0)+5(4)+20(19)+2(1)
=
756               
0+20+380+2
=
756
402
=
1.9