Glossary of Biodiversity Measures
- Species Richness - The number of different species found in a particular environment.
- Biodiversity - The number of different species of organisms in a particular environment.
- Evenness (E) - A measure of how similar the abundances of different species are in the community.
- Shannon-Weiner index (H) - This diversity measure came from information theory and measures the order (or disorder) observed within a particular system. In ecological studies, this order is characterized by the number of individuals observed for each species in the sample plot (e.g., biofilm on a plexiglass disc).
- Simpson's index (D) - The probability that two randomly selected individuals in the community belong to the same category (e.g., species).
- Simpson's index of diversity (1 - D) - The probability that two randomly selected individuals in a community belong to different categories (e.g., species).
- Simpson's reciprocal index (1/D) - The number of equally common categories (e.g., species) that will produce the observed Simpson's index.
Script written by Maryland Sea Grant