# How to calculate species abundance and diversity

by blicker
Tags: abundance, biology, diversity
 P: 19 1. The problem statement, all variables and given/known data This is the sample population taken along a 5m transect: ants:9 grasshoppers:1 pill bugs:4 spiders:1 2. Relevant equations What formulas would i use to calculate the species abundance and diversity? 3. The attempt at a solution I only know this formula H'=-$\Sigma$ (n$_{}i$/N)xIn(n$_{}i$/N) and i dont know what to do with this formula. 1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution
 HW Helper P: 6,189 Hi blicker! Can it be that your formula is actually: where "ln" is the natural logarithm (and also a button on your calculator), and where ni is the number of individuals of species i? See: http://en.wikipedia.org/wiki/Shannon_index
 P: 19 yes thats it! but i dont know what numbers go where or how to calculate it. like would i include the sigma symbol and the letters above and below it?
 HW Helper P: 6,189 How to calculate species abundance and diversity The sigma symbol indicates that you have to sum. So: $$H'=-\sum_{i=1}^S {n_i \over N} \ln {n_i \over N} = -({n_1 \over N} \ln {n_1 \over N} + {n_2 \over N} \ln {n_2 \over N} + {n_3 \over N} \ln {n_3 \over N} + {n_4 \over N} \ln {n_4 \over N})$$ From wiki: * ni The number of individuals in species i; the abundance of species i. * S The number of species. Also called species richness. * N The total number of all individuals * pi The relative abundance of each species, calculated as the proportion of individuals of a given species to the total number of individuals in the community: $n_i\over N$
 P: 19 so would the equation for ants look like this: -(9/15)In(9/15)
HW Helper
P: 6,189
 Quote by blicker so would the equation for ants look like this: -(9/15)In(9/15)
Well, Shannon's index specifies to sum all the terms.
So what you mention is only part of H'.

Btw, it is $ln$ ("logarithmus naturalis").

And apparently $n_i$ is the "species abundance".
Furthermore $p_i={n_i \over N}$ is the "relative species abundance".