Simpson’s Index

• Biodiversity


  The variety of different species in an area and the relative abundance of each
• Simpson's Index


  A measure of biodiversity that takes into account both the number of species and the relative abundance of each species
• Calculating Simpson's Index


  1. Step 1: Calculate n/N for each species

  2. Step 2: Square each of these values

  3. Step 3: Add them together and subtract the total from 1
• Simpson's Index


  • Values near 1 indicate high levels of biodiversity
  • Values near 0 indicate low levels of biodiversity
• Species diversity looks at the number of different species in an area (species richness) but also the evenness of abundance across the different species in that area (species evenness)
• The formula for Simpson's Index is: D = 1 - ((n/N)²)