Enter your Total Individuals, Species Observed, Most Abundant Species Count, and Singleton Species into the Species Richness Calculator to find your Estimated Total Richness, Shannon (H') and Simpson's (D) Indices, and Species Evenness.
Estimated Total Species Richness
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Observed Species Richness
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Shannon Diversity Index (H')
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Simpson's Diversity Index (D)
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Pielou's Evenness (J')
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Species Density
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Species richness is the total number of different species present in an ecosystem or community. It's a fundamental measure of biodiversity that helps ecologists understand ecosystem health, stability, and conservation priorities.
Observed richness is the actual number of species found in your sample, while estimated richness uses statistical methods to predict the total number of species that likely exist in the ecosystem, including those not captured in your sample.
Chao1 is most commonly used and works well for most datasets. ACE performs better with larger samples, while Jackknife estimators are good for smaller samples. Bootstrap provides conservative estimates and confidence intervals.
The Shannon index (H') measures both species richness and evenness in a community. Higher values indicate greater diversity, typically ranging from 1.5 to 3.5 in natural ecosystems, with values above 3 considered very diverse.
Simpson's index (D) ranges from 0 to 1, where values closer to 1 indicate higher diversity. It represents the probability that two randomly selected individuals belong to different species.
Pielou's evenness (J') measures how evenly individuals are distributed among species, ranging from 0 to 1. Values near 1 indicate species have similar abundances, while lower values suggest some species dominate.
Larger samples generally provide better estimates. For most ecosystems, samples of 300-500 individuals across multiple sampling points give reliable results. Very small samples may underestimate true diversity.
Yes, but be cautious about comparing ecosystems with very different organism types or sampling methods. Standardize your sampling effort and consider using multiple diversity metrics for comprehensive comparisons.