1. What is the Shannon-Wiener Index?

The Shannon-Wiener Index 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 formula:

Where:

• \( H \) — Shannon-Wiener diversity index
• \( T \) — Number of time periods
• \( S \) — Number of species
• \( p_{i,t} \) — Proportion of individuals belonging to species i in time period t
• \( \ln \) — Natural logarithm

Explanation: The index measures both the number of species and their relative abundances across multiple time periods.

3. Importance of Shannon-Wiener Index

Details: This index is crucial for ecological studies, biodiversity assessment, and monitoring changes in community structure over time. Higher values indicate greater diversity.

4. Using the Calculator

Tips: Enter the number of time periods and provide proportions for each period as comma-separated values. Each line represents one time period, and proportions should sum to 1 for each period.

5. Frequently Asked Questions (FAQ)

Q1: What is the range of Shannon-Wiener Index values?
A: Typically ranges from 0 (only one species) to about 4-5 (high diversity), though the maximum depends on the number of species.

Q2: How does time affect the Shannon-Wiener Index?
A: The time component allows tracking diversity changes over multiple periods, showing trends in biodiversity.

Q3: What's the difference between Shannon and Simpson indices?
A: Shannon index is more sensitive to rare species, while Simpson index emphasizes dominant species.

Q4: Can proportions be entered as percentages?
A: No, proportions must be entered as decimal values between 0 and 1 that sum to 1 for each time period.

Q5: What if proportions don't sum to 1?
A: The calculator will return an error. Ensure the sum of proportions for each time period equals 1.