Analyze species abundance with practical alpha diversity measures. Review richness, evenness, and dominance key outputs. Download clean reports and compare biological samples with confidence.
| Species | Abundance |
|---|---|
| Species 1 | 18 |
| Species 2 | 11 |
| Species 3 | 9 |
| Species 4 | 6 |
| Species 5 | 4 |
| Species 6 | 2 |
| Species 7 | 1 |
| Species 8 | 1 |
Observed Richness: S = number of species with abundance greater than zero.
Total Individuals: N = sum of all species abundances.
Relative Abundance: pi = ni / N.
Shannon Index: H' = -Σ(pi log pi). The selected log base controls the scale.
Simpson Dominance: D = Σ(pi2).
Simpson Diversity: 1 - D.
Inverse Simpson: 1 / D.
Pielou Evenness: J' = H' / log(S).
Margalef Richness: (S - 1) / ln(N).
Menhinick Richness: S / √N.
Berger-Parker Dominance: max(ni) / N.
Chao1 Estimated Richness: S + F12 / (2F2), or a bias-adjusted fallback when F2 is zero.
Fisher's Alpha: solved iteratively from S = α ln(1 + N / α).
Alpha diversity describes the variety found inside one biological sample. It measures how many species are present and how evenly individuals are distributed. A community with many species may still have low diversity if one species dominates. This is why ecologists review several indices together. Richness shows the number of detected species. Evenness shows balance across species. Dominance highlights whether one taxon controls the sample. Shannon and Simpson indices combine these ideas into practical summary values.
Alpha diversity helps compare soil, water, gut, plant, and wildlife communities. Researchers use it during biodiversity surveys, microbiome analysis, habitat monitoring, and conservation planning. A higher value can suggest a more balanced ecosystem, but interpretation depends on sampling design and ecology. Rare species also matter. Estimators such as Chao1 help infer unseen richness from singletons and doubletons. This can improve interpretation when sampling is incomplete.
This calculator accepts species abundance counts and returns core alpha diversity outputs. You can review total individuals, observed richness, Shannon index, Simpson dominance, Simpson diversity, inverse Simpson, Pielou evenness, Margalef richness, Menhinick richness, Berger-Parker dominance, and Fisher's alpha. Each metric answers a slightly different ecological question. Together they provide a broader picture than any single number.
Use Shannon when you need sensitivity to both richness and evenness. Use Simpson when dominant species matter more. Use Pielou evenness to judge balance across detected species. Use Margalef and Menhinick to compare richness while considering sample size. Use Berger-Parker to identify strong dominance. Fisher's alpha is useful for comparing communities with different abundance distributions. Always compare results alongside metadata, sampling depth, and study goals.
Prepare abundance data carefully before calculating diversity. Use counts from the same sampling unit. Remove negative values and obvious entry errors. Keep zeros only if they represent recorded taxa, because this tool ignores zero counts during analysis. For microbiome work, use consistent preprocessing across samples. For field surveys, align taxonomic resolution before comparing sites. Stable methods improve interpretation. Clean inputs make exported tables and reports easier to review, share, and archive for future biological assessments within research teams and client updates.
Alpha diversity measures diversity within one sample or site. It summarizes richness, evenness, and dominance using one or more indices.
Shannon index gives weight to both richness and evenness. Simpson metrics are more influenced by dominant species and are often more stable when abundance is uneven.
Yes. The calculator ignores zero values during computation because alpha diversity metrics rely on taxa with observed abundance greater than zero.
Use counts from the same sampling effort, method, and taxonomic level. Differences in sequencing depth or field effort can affect interpretation.
Chao1 estimates potential richness by using rare taxa information. It is useful when many species appear only once or twice.
There is no universal cutoff. A higher value can indicate more balance or richness, but ecological meaning depends on habitat, sample type, and study design.
Yes. The CSV export is useful for spreadsheets, and the PDF export creates a clean report for sharing or archiving.
No. It is a decision aid, not a substitute for ecological expertise. Always interpret values with metadata, sampling design, and biological context.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.