1. What is Simpson's Diversity Index?

Simpson's Diversity Index (D) measures the probability that two randomly selected individuals from a sample will belong to the same species. It ranges from 0 (infinite diversity) to 1 (no diversity).

2. How Does the Calculator Work?

The calculator uses the Simpson's Index formula:

Where:

• \( n_i \) — Number of individuals of species i
• \( N \) — Total number of individuals
• \( D \) — Simpson's Diversity Index (0-1)

Explanation: The index calculates the probability that two randomly selected individuals belong to the same species.

3. Interpretation of Results

Details: Lower values indicate greater diversity. A value of 0 means infinite diversity, while 1 means no diversity (all individuals belong to one species).

4. Using the Calculator

Tips: Enter counts of each species separated by commas (e.g., "5,10,15,20"). All values must be positive integers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between Simpson's Index and Shannon Index?
A: Simpson's emphasizes dominant species while Shannon emphasizes species richness.

Q2: What does a value of 0.5 mean?
A: There's a 50% chance two randomly selected individuals belong to the same species.

Q3: How many species should I include?
A: Include all species in your sample for accurate results.

Q4: Can I use this for very large samples?
A: Yes, the calculator can handle large numbers.

Q5: What's the inverse Simpson index?
A: 1/D gives the effective number of species (number of equally common species needed to get the same D).