Diversidade gamma (regional)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
This calculator estimates gamma diversity, which represents the total species diversity in a region or landscape. Gamma diversity is calculated by multiplying alpha diversity (average number of species within local communities) by beta diversity (ratio of regional to local diversity). The multiplicative model γ = α × β is the most common in ecology, indicating that regional diversity is the product of local diversity and the rate of species turnover among communities.
To use the tool, enter the alpha diversity value (average number of species per sample or site) and the beta diversity value (measure of species replacement between sites). The result shows the expected gamma diversity. This calculation is useful for conservation planning, comparing different regions, or assessing the impact of disturbances on biodiversity at a regional scale.
Important precautions: beta diversity can be expressed in different ways (Whittaker indices, Jaccard, etc.). Ensure that your beta measure is compatible with the multiplicative model. Also, alpha diversity should be the simple arithmetic mean of local richness. Avoid using values without a common unit or mixing different scales.
Frequently asked questions
What is the difference between alpha, beta, and gamma diversity?
Alpha is local diversity (within a sample). Beta is the difference between samples (turnover). Gamma is the total regional diversity. In the multiplicative model, gamma = alpha × beta.
Can I use this calculator with the additive model (γ = α + β)?
No. This calculator only uses the multiplicative model. For the additive model, please use another specific tool for additive diversity.
What units should I use for alpha and beta?
Both should be dimensionless numbers. Alpha is the average number of species, beta is a ratio or index without units.
What does it mean if beta equals 1?
A beta of 1 indicates no turnover among communities, meaning the samples are identical. In that case, gamma equals alpha.
Does this calculator work for diversity indices that consider abundance?
No. It is based solely on species richness (number of species). For abundance-weighted indices (Shannon, Simpson), other calculations are required.