ChaoRichness: Estimation of species richness

In iNEXT: Interpolation and Extrapolation for Species Diversity

Estimation of species richness

Description

ChaoRichness: estimation of species richness based on the methods proposed in Chao (1984, 1987)

Usage

ChaoRichness(x, datatype = "abundance", conf = 0.95)

Arguments

x	a matrix, data.frame (species by sites), or list of species abundances or incidence frequencies. If datatype = "incidence_freq", then the first entry of the input data must be total number of sampling units, followed by species incidence frequencies.
datatype	data type of input data: individual-based abundance data (datatype = "abundance"), sampling-unit-based incidence frequencies data (datatype = "incidence_freq") or species by sampling-units incidence matrix (datatype = "incidence_raw").
conf	a positive number \le 1 specifying the level of confidence interval.

Value

A data.frame of observed species richness, species richness estimate, s.e. and the associated confidence interval.

References

Chao, A. (1984) Nonparametric estimation of the number of classes in a population. Scandinavian Journal of Statistics, 11, 265-270.

Chao, A. (1987) Estimating the population size for capture-recapture data with unequal catchability. Biometrics, 43, 783-791.

See Also

ChaoShannon, ChaoSimpson

Examples

data(spider)
ChaoRichness(spider$Girdled, datatype="abundance")

iNEXT documentation built on Aug. 8, 2025, 6:41 p.m.