Biodiversity Analyst > Biodiversity Indices

Richness Indices

Species Richness of an ecosystem represents the numbers of species in that ecosystem. Higher richness index value represents the system has various kinds of species. For example,

And the richness indices can be implemented in Biodiversity Analyst are Richness, Margalef, and Menhinick.

•Richness Index

We can see the Richness index of the selected area is "1", which implies that there is only one species in the sample area.

•Margalef Index

The corresponding image shall be:

A sample area with fewer species shall conclude a smaller Margalef Index value.

•Menhinick Index

The richness indices concern only about the abundance of each species. That the proportion of species would be less evenly when the total abundance is getting larger is often a case in nature community. So if a sample area doesn't have equal number for each species, these kinds of indices wouldn't reveal the evenness.

For instance:

You can see obviously, in graph A and B they have the same number of species; even graph A has a great number of , but the total number is different. The sum of samples for A is 12 but the sum of samples for B is 5.