1. What is the Shannon-Wiener Index?

The Shannon-Wiener Index (H) is a measure of diversity that combines species richness and evenness. It quantifies the uncertainty in predicting the species of an individual chosen at random from the community.

2. How Does the Calculator Work?

The calculator uses the Shannon-Wiener Index formula:

Where:

• \( p_i \) — 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 abundances increase.

3. Importance of Shannon-Wiener Index

Details: This index is widely used in ecology to measure biodiversity. Higher values indicate greater diversity, while lower values indicate less diversity or dominance by a few species.

4. Using the Calculator

Tips: Enter proportions as comma-separated values (e.g., 0.3,0.4,0.3). All proportions must be between 0 and 1, and the sum must equal 1.

5. Frequently Asked Questions (FAQ)

Q1: What is a good Shannon-Wiener Index value?
A: Typically, values range from 1.5 to 3.5, with higher values indicating greater diversity. The maximum value depends on the number of species.

Q2: How does this differ from Simpson's Index?
A: Shannon-Wiener is more sensitive to rare species, while Simpson's Index gives more weight to common species.

Q3: Can I use percentages instead of proportions?
A: Yes, but divide by 100 first (e.g., 30%,40%,30% becomes 0.3,0.4,0.3).

Q4: What if my proportions don't sum to exactly 1?
A: The calculator requires the sum to be 1 (within a small tolerance). Normalize your data if necessary.

Q5: What base logarithm is used?
A: The natural logarithm (base e) is standard for the Shannon-Wiener Index.