abc: Abundance and Biomass Comparison Method

In forams: Foraminifera and Community Ecology Analyses

Abundance and Biomass Comparison Method

Description

This function performs the ABC and W statistic calculation.

Usage

  abc(df, Perm, confInt)

Arguments

df	a numeric data frame containing the abundance and biomass as columns and taxa as rows. NAs are not allowed.
Perm	the number of permutations to be realized for calculating the Confidence Interval.
confInt	the Confidence interval range (90%, 95% or 99%, any other values will cause an error).

Details

The function generates a list of cumulative percentage values of Abundance, Biomass and Biomass - Abundance for each taxon (Warwick 1986), which are used for W statistic (Warwick & Clarke 1994) calculation and posterior k-dominance curve plotting.

Value

An abc S4 object has the fallowing elements:

An abc slot with:

Accum.Abun	The cumulative percentage of abundance contribution.
Accum.Biomass	The cumulative percentage of biomass contribution.
BiAi	Biomass - Abundance calculation results.

and a W.Stat slot with:

W.Stat

The result of the W statistic calculation and its Confidence Interval.

Note

The list elementes are ordered according to Accum.Abun, but the calculation is based on the contribution decreasing order, independently of any of the variables or taxon.

Author(s)

Rodrigo Aluizio

References

Warwick, R.M. (1986). A new method for detecting pollution effects on marine macrobenthic communities. Marine Biology 92 (4), 557-562.

Warwick, R.M., & Clarke, K.R. (1994). Relearning the ABC: taxonomic changes and abundance/biomass relationships in disturbed benthic communities. Marine Biology 118 (4), 739-744.

Examples

data(NB)
MyABC <- abc(NB)
plot(MyABC)

forams documentation built on Aug. 24, 2023, 5:11 p.m.