Simpson's Biodiversity Index Calculator

Simpson's Index Formula:

\[ D = 1 - \frac{\sum n_i(n_i - 1)}{N(N - 1)} \]

Simpson's Index (D):

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1. What is Simpson's Biodiversity Index?

Simpson's Biodiversity Index (D) measures the diversity of species in a community. It represents the probability that two individuals randomly selected from a sample will belong to different species. Higher values indicate greater diversity.

2. How Does the Calculator Work?

The calculator uses Simpson's Index formula:

\[ D = 1 - \frac{\sum n_i(n_i - 1)}{N(N - 1)} \]

Where:

\( n_i \) — Number of individuals of each species
\( N \) — Total number of individuals
\( \sum \) — Summation across all species

Explanation: The index calculates the probability that two randomly selected individuals belong to different species, with values ranging from 0 (no diversity) to nearly 1 (very high diversity).

3. Importance of Biodiversity Measurement

Details: Simpson's Index is widely used in ecology to quantify biodiversity, assess ecosystem health, and monitor changes in species composition over time or across different habitats.

4. Using the Calculator

Tips: Enter population counts for each species separated by commas. The calculator will compute the total population and apply Simpson's formula to determine the diversity index.

5. Frequently Asked Questions (FAQ)

Q1: What does a Simpson's Index value of 0.8 mean?
A: A value of 0.8 indicates an 80% probability that two randomly selected individuals belong to different species, representing high diversity.

Q2: How does Simpson's Index differ from other diversity indices?
A: Unlike species richness counts, Simpson's Index considers both species abundance and evenness, giving more weight to common species.

Q3: What are the limitations of Simpson's Index?
A: It may be less sensitive to rare species and can be influenced by sample size. Very small populations may yield unreliable results.

Q4: Can Simpson's Index be greater than 1?
A: No, Simpson's Index ranges from 0 to 1, where 0 represents no diversity and values closer to 1 indicate higher diversity.

Q5: How should I interpret different Simpson's Index values?
A: Values closer to 0 indicate low diversity (dominated by few species), while values closer to 1 indicate high diversity (many species with more even distribution).