Shannon Diversity Index Calculator
Measure species diversity and evenness in ecological communities
Species Data Input
Calculation Settings
Species Count Data
Understanding the Shannon Diversity Index
The Mathematical Formula
Where:
- H = Shannon diversity index
- pᵢ = Proportion of individuals of species i (nᵢ/N)
- nᵢ = Number of individuals of species i
- N = Total number of individuals in the community
- Σ = Sum over all species
- log = Logarithm (base can vary)
What the Index Measures
Species Richness
The number of different species present in the community
Species Evenness
How evenly individuals are distributed among species
Interpretation Guidelines
| Shannon Index Range | Diversity Level | Ecological Meaning |
|---|---|---|
| H = 0 | No Diversity | Only one species present |
| 0 < H < 1 | Low Diversity | Few species, often dominated by one |
| 1 ≤ H < 2 | Moderate Diversity | Several species with moderate evenness |
| 2 ≤ H < 3 | High Diversity | Many species with good distribution |
| H ≥ 3 | Very High Diversity | Exceptional species richness and evenness |
Ecological Applications & Conservation
🌍 Real-World Applications
Forest Ecosystems
Assess tree species diversity for sustainable forest management and biodiversity conservation
Marine Conservation
Monitor fish species diversity in marine protected areas and coral reef systems
Urban Ecology
Evaluate bird and plant diversity in urban parks and green infrastructure
Agricultural Systems
Assess beneficial insect diversity and pollinator communities in farmlands
🔬 Scientific Benefits
- Standardized metric for comparing diversity across different habitats
- Incorporates both species richness and abundance patterns
- Widely accepted in ecological research and environmental assessments
- Useful for monitoring ecosystem health and conservation success
- Helps identify areas requiring targeted conservation efforts
🌱 Conservation Action Steps
- Investigate environmental stressors (pollution, habitat loss)
- Implement habitat restoration programs
- Consider species reintroduction where appropriate
- Remove invasive species that may be suppressing natives
- Maintain current protection and management strategies
- Monitor for early warning signs of diversity loss
- Ensure habitat connectivity for species movement
- Implement adaptive management for climate resilience
Example Scenarios
Interpretation Guide
1 = all species equally abundant
Data Collection Tips
How This Calculator Works
Step-by-Step Calculation
- Calculate the total number of individuals (N) across all species
- For each species, calculate its proportion: pᵢ = nᵢ/N
- Calculate the natural logarithm of each proportion: ln(pᵢ)
- Multiply each proportion by its logarithm: pᵢ × ln(pᵢ)
- Sum all values from step 4
- Multiply the sum by -1 to get the Shannon index
- Calculate evenness: E = H / ln(S), where S is species richness
Logarithm Base Effects
The choice of logarithm base affects the absolute values but not the relative rankings of different communities.
Scientific Use: This calculator is designed for educational and research purposes. The Shannon diversity index is one of many diversity metrics. For comprehensive biodiversity assessments, consider using multiple indices and consult with professional ecologists. Always ensure proper sampling methodology and species identification accuracy.
Also Known As: Shannon-Wiener Index, Shannon-Weaver Index
Last Updated: September 2024