1. What is the Shannon Diversity Index?

The Shannon Diversity Index (H) is a measure of diversity that considers both species richness and evenness. It quantifies the uncertainty in predicting the species identity of an individual randomly selected from the community.

2. How Does the Calculator Work?

The calculator uses the Shannon Diversity Index equation:

Where:

• \( H \) — Shannon diversity index
• \( p_i \) — Proportion of species i in the community
• \( \ln \) — Natural logarithm

Explanation: The index increases as both the number of species and the evenness of their proportions increase.

3. Importance of Diversity Measurement

Details: The Shannon index is widely used in ecology, conservation biology, and microbiome studies to assess community diversity and compare different habitats or treatments.

4. Using the Calculator

Tips: Enter species proportions as comma-separated values (e.g., 0.2,0.3,0.5). The calculator will normalize them to sum to 1. Values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a good Shannon index value?
A: Values typically range from 1.5 to 3.5 in most ecological studies. Higher values indicate greater diversity.

Q2: How does this differ from Simpson's index?
A: Shannon index is more sensitive to rare species, while Simpson's index emphasizes dominant species.

Q3: What's the maximum possible value?
A: Maximum is ln(S) where S is number of species, achieved when all species are equally abundant.

Q4: Can I use counts instead of proportions?
A: Yes, the calculator will convert counts to proportions automatically.

Q5: When should I use this index?
A: When you want to consider both species richness and evenness in your diversity assessment.