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Species Richness Calculator

Richness Indices

Calculate Margalef and Menhinick indices from species and individual counts

Rarefaction Estimate

Estimate expected species at a smaller sample size using rarefaction

Formula

Margalef: DMg = (S − 1) / ln(N). Menhinick: DMn = S / √N. Where S = number of species, N = total individuals.

Frequently Asked Questions

What is species richness?
Species richness is simply the number of different species present in a sample or community. Unlike diversity indices, it does not account for the relative abundance of each species.
What is the Margalef index?
The Margalef richness index adjusts species count for sample size: DMg = (S−1)/ln(N). It accounts for the fact that more species are found in larger samples.
What is rarefaction?
Rarefaction is a method to compare species richness between samples of different sizes. It estimates the expected number of species in a smaller random subsample drawn from the full dataset.

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