1. What is the Shannon Diversity Index?

The Shannon Diversity Index (H) is a measure of species diversity in a community that accounts for both abundance and evenness of species present. It's widely used in ecology to quantify biodiversity.

2. How Does the Calculator Work?

The calculator uses the Shannon Diversity Index formula:

Where:

• \( H \) — Shannon Diversity Index value
• \( p_i \) — Proportion of individuals belonging to species i
• \( \ln \) — 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 helps ecologists compare diversity between habitats, monitor changes over time, and assess ecosystem health.

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, with higher values indicating 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: Can I use counts instead of proportions?
A: Yes, the calculator will convert counts to proportions automatically.

Q4: What does a zero value mean?
A: H=0 means the community has only one species (no diversity).

Q5: How should I interpret the results?
A: Compare values between similar habitats. Higher H = more diverse community.