1. What is the Simpson Index?

The Simpson Index (D) measures biodiversity by accounting for both species richness and evenness. It represents the probability that two randomly selected individuals from a sample will belong to different species.

2. How Does the Calculator Work?

The calculator uses the Simpson Index equation:

Where:

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

Explanation: The index approaches 1 when diversity is high (many species with even distribution) and approaches 0 when diversity is low (dominance by one species).

3. Importance of Diversity Index

Details: The Simpson Index is widely used in ecology to quantify biodiversity in a habitat. It helps in conservation planning and monitoring ecosystem health.

4. Using the Calculator

Tips: Enter counts of individuals for each species, separated by commas. All counts must be positive integers.

5. Frequently Asked Questions (FAQ)

Q1: What does a Simpson Index of 0.8 mean?
A: An index of 0.8 indicates high diversity - there's an 80% chance two randomly selected individuals will be from different species.

Q2: How does this differ from Shannon Index?
A: While both measure diversity, Shannon Index is more sensitive to rare species, while Simpson Index emphasizes dominant species.

Q3: What's a good diversity value?
A: Values closer to 1 indicate greater diversity, but interpretation depends on the ecosystem. Typically 0.6-0.9 is considered good diversity.

Q4: Can I use this for microbial communities?
A: Yes, but ensure your sampling method captures the true diversity as microbial communities often have many rare species.

Q5: How many species should I include?
A: The more species you include, the more accurate your index will be. Typically at least 10-20 species are recommended.