How to Calculate Biodiversity Index (Shannon)
What is Biodiversity Index (Shannon)?
The Shannon-Wiener diversity index H' measures biodiversity combining species richness and evenness. H' = −Σ(pᵢ × ln pᵢ).
Step-by-Step Guide
- 1pᵢ = nᵢ/N for each species
- 2H = −Σ(pᵢ × ln pᵢ)
- 3H_max = ln(S) · Evenness J = H/H_max
Worked Examples
Input
Species counts: 50, 30, 20
Result
H = 1.03 · J = 0.94
High evenness despite only 3 species
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