The Simpsons Diversity Index allows us to measure the degree of biodiversity in a given biological ecosystem. For example, a forest may have many different species of animals such as tigers, leopards, deer, etc. The Simpsons diversity index can then allow us to compare two different forests in order to determine which has a higher degree of biodiversity.
The Simpson biodiversity index can simply be calculated by entering the frequencies of each of the different species in the table below.
Simpson’s Diversity Index (D): 0.343
Dominance Index (1 – D): 0.657
Simpson’s Reciprocal Index (1 / D): 2.917
The value of the Simpsons Diversity Index always lies between 0 and 1. If there is a high degree of biodiversity then the value of the Simpsons will lie closer to 1. If the degree of biodiversity is low then the value will lie closer to zero.
The interpretation of the Simpsons Dominance Index is completely the opposite. Higher values closer to 1 indicate a higher degree of biodiversity and lower values of the dominance index (closer to 0) indicate a lower degree of biodiversity.