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Simpson's Diversity Index Formula:
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Simpson's Diversity Index is a measure of biodiversity that takes into account both species richness (number of species) and species evenness (how evenly individuals are distributed among species). It quantifies the probability that two individuals randomly selected from a sample will belong to different species.
The calculator uses Simpson's Diversity Index formula:
Where:
Explanation: The index ranges from 0 to 1, where 0 indicates no diversity (all individuals belong to one species) and values closer to 1 indicate high diversity.
Details: Simpson's Diversity Index is widely used in ecology, conservation biology, and environmental science to assess ecosystem health, monitor biodiversity changes, and compare different habitats or communities.
Tips: Enter the count of individuals for each species separated by commas. For example, if you have 10 individuals of species A, 5 of species B, and 3 of species C, enter "10,5,3". All values must be positive integers.
Q1: What does a high Simpson's Index value mean?
A: Higher values (closer to 1) indicate greater diversity, meaning many species are present and no single species dominates the community.
Q2: How does Simpson's Index differ from Shannon Index?
A: Simpson's Index gives more weight to common species, while Shannon Index is more sensitive to rare species. Simpson's is better for assessing dominance.
Q3: What is the range of Simpson's Diversity Index?
A: The index ranges from 0 to 1, where 0 represents no diversity and 1 represents infinite diversity (theoretical maximum).
Q4: When should I use Simpson's Index?
A: Use it when you want to emphasize the probability of interspecific encounters or when common species are more important for your study.
Q5: Can Simpson's Index be greater than 1?
A: No, the standard Simpson's Diversity Index (1 - Σp_i²) ranges from 0 to 1. Some variations exist but this is the most commonly used form.