Sample Data                                            ;      Analysis

Blanchards Cricket Frog - 15                       Mean = (15 + 5 + 8 + 3 + 6)/5 = 7.4

Gray Treefrog                -  5                         Species Richness = total number of                                      &n bsp;                                                            species found

American Toad              -  8                                         &n bsp;           = 5

Northern Spring Peeper -  3                          Species Diversity = 0.74

Southern Leopard Frog  -  6                                     (as shown below)

Calculating diversity using the Simpson Diversity Index

Calculate the proportion of the total number of amphibians of each species (Pi).

Proportion species A (Pa) = number of species A/Total number of amphibians
Proportion species B(Pb) = number of species B/Total number of amphibians

To calculate the Simpson Diversity Index = 1 - sum(Pi)2

         (meaning add the proportion of each squared species and take it from 1)

Using the example above, you have 15 cricket frogs, 5 gray treefrogs, 8 american toads, 3 spring peepers, and 6 leopard frogs. You would calculate:

Diversity Index = 1- ((15/37)2 + (5/37)2 + (8/37)2 + (3/37)2 + (6/37)2)
Diversity Index = .74