Use Williams Alpha when you need to compute Williams alpha diversity as the regional species count divided by the number of habitats sampled. Enter Regional species and Habitats sampled using the definitions and units below so the result can be reproduced.

Regional species

An integer count or setting greater than or equal to 1, expressed in species.

Habitats sampled

An integer count or setting greater than or equal to 1, expressed in habitats.

The published tool contract uses this rule: Compute Williams alpha diversity as the regional species count divided by the number of habitats sampled.

Williams alpha diversity

The calculated williams alpha diversity.

A ratio or percentage can conceal the scale of its numerator and denominator and becomes sensitive to measurement error when the denominator is small.

Retain the original Regional species and Habitats sampled values and their units alongside the result. Fisher Alpha is useful when you instead need to solve Fisher's log-series diversity parameter from S = alpha × ln(1 + N/alpha). A finite positive solution exists when the observed species count is smaller than the individual count. Log Series Alpha Proxy provides another view by helping you compute a documented Fisher-lite proxy for the log-series alpha parameter as species count divided by the natural logarithm of total individuals plus one.

• Fisher Alpha

  Solve Fisher's log-series diversity parameter from S = alpha × ln(1 + N/alpha). A finite positive solution exists when the observed species count is smaller than the individual count.

• Log Series Alpha Proxy

  Compute a documented Fisher-lite proxy for the log-series alpha parameter as species count divided by the natural logarithm of total individuals plus one.

• Whittaker Beta Diversity

  Compute Whittaker beta diversity betaW = gamma / mean alpha richness from two site species counts and their shared count.