Community Characteristics-II

2.     Species Diversity

The major biodiversity measurements are species richness, Shannon Weiner Index and Simpson’s Index. Species diversity comprised of two factors species evenness and species richness (number of species).

Species evenness indicates the relative abundance of each species.

 Community “1”

Community “2”

Both communities have three types of plant species depicting same species richness but relative abundance vary.

In community “1” species A, B and C are equal in proportion (three each) indicating higher species evenness thus revealed higher species diversity.

In community “2” species C is more in proportion indicating low species evenness and species diversity.

Shannon-Weiner Index

It’s a common Index of species diversity represented as 

Hᵒ is the diversity index, the proportion of i^th species is represented as p_i while “s” is species richness i.e. number of species in community.