Biodiversity Index Calculator
Calculate ecological diversity indices including Shannon-Wiener Index, Shannon Evenness, and Simpson's Index from species distribution data.
Species Sample Data
Enter individual counts for up to 5 species.
Shannon-Wiener Index (H')
Shannon Evenness (E)
Simpson's Index of Diversity (1 - D)
Ecosystem Diversity
Higher Shannon ($H' > 2.5$) and Simpson ($1-D > 0.8$) values indicate stable ecosystems with high resilience to disturbances.
Typical Diversity Indices Across Global Biomes Reference
| Biome / Ecosystem Type | Typical Shannon Index (H') | Simpson Index (1 - D) | Diversity Level |
|---|---|---|---|
| Tropical Rainforest | 3.5 ā 4.5 | 0.90 ā 0.98 | Very High (Hyperdiverse) |
| Temperate Deciduous Forest | 2.0 ā 3.0 | 0.70 ā 0.85 | Moderate to High |
| Agricultural Monoculture | 0.1 ā 0.5 | 0.05 ā 0.20 | Very Low (Dominated) |
Methodology & Equations
Shannon-Wiener Formula
Where $p_i = (n_i / N)$ is the relative proportion of individuals belonging to species $i$.
Simpson's Diversity Formula
Calculates finite-sample probability that two picked individuals are different species.
Frequently Asked Questions
What is the Shannon-Wiener Diversity Index (H')? ā¼
The Shannon-Wiener index ($H' = -sum p_i ln p_i$) measures ecosystem species diversity by accounting for both species richness ($S$) and relative abundance ($p_i$). Values typically range between 1.5 and 3.5.
What does Simpson's Index of Diversity (1 - D) represent? ā¼
Simpson's Index of Diversity ($1 - D = 1 - sum (n_i (n_i - 1) / N (N - 1))$) represents the probability that two individuals randomly selected from a sample belong to different species.
What is Shannon Evenness (E)? ā¼
Shannon Evenness ($E = (H' / ln S)$) quantifies how equally abundant the species are. A value of 1.0 indicates complete equality across all species.
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