riqueza espécies
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
Chao1 estimador
About this calculator
Species richness measures the total number of species in an ecosystem. This calculator uses the Chao1 estimator, which corrects underestimates caused by undetected rare species in samples. The method adjusts the richness estimate by analyzing species observed once or twice in the data.
The Chao1 estimator is valuable in ecological studies where sampling might miss biodiversity. It's applied in protected area assessments, environmental impact analyses, or monitoring fragile ecosystems. Accuracy depends on data quality and sample representativeness.
To use the calculator, input the number of observed species and their occurrence frequencies (species with 1 or 2 records). Avoid incomplete or very small samples, as they reduce reliability. The result is an estimate of actual richness, accounting for potentially unrecorded species.
Typical applications include mangrove restoration tracking, insect monitoring in forests, or assessing pollutants in water bodies. Chao1 helps determine if sampling is sufficient to represent local biodiversity, signaling when more collections are needed.
Frequently asked questions
How does the Chao1 estimator work?
Chao1 adjusts observed species counts using the frequency of rare species (seen once or twice) to estimate 'hidden' species missed by sampling.
When should I use this calculator?
Use it to estimate biodiversity in ecosystems with partial sampling, like forests or water bodies with limited data.
What is the minimum sample size?
At least 10 samples per site are recommended. Smaller samples increase error risk due to statistical dependencies.
Why do results vary between analyses?
Variation occurs from sampling randomness and uneven species distribution. Repeat sampling across seasons is advised.
What if there's no data on rare species?
Chao1 requires rare species records (seen once/twice). Without them, the true richness might be underestimated.