Simpson's diversity index

• considers species richness and evenness
• calculates the probability that any two species drawn at random from a collection, will produce
  two different species
• ranges between 0 and 1, with value closer to 0 meaning there is high diversity

Shannon diversity index H'

• considers species richness and relative abundance
• Hmax = ln(S) occurs when all species have same relative abundance (maximum evenness)
• higher score of H' is more diverse
• H'<1.5 = low diversity
• 1.5<H'< 3.5 = moderate diversity
• H'>3.5 = high diversity

Simpson's evenness index

• ranges from 0-1, 1= complete evenness

Shannon evenness

• compares the abundance of each species in the community
• E ranges from 0-1, 1= complete evenness