Rank-abundance curves

This function draws a rank-abundance curve for community data. You can optionally add labels for a selected number of species. If you wish to draw multiple rank-abundance curves for selected samples use racurves.

racurve(
  matrix,
  main = "Rank-abundance diagram",
  nlab = 0,
  ylog = FALSE,
  frequency = FALSE,
  ylim = NULL,
  xlim = NULL
)

Arguments

matrix: Community data, a matrix-like object with samples in rows.
main: The main title (optional).
nlab: Number of labeled species (default = 0). Species are labeled in decreasing order beginning from the highest relative abundance.
ylog: If set on TRUE the y-axis is displayed on a log-scale.
frequency: If set on TRUE frequencies of species are calculated instead of relative abundances.
xlim, ylim: Define axis limits

Value

Returns an (invisible) list composed of:

abund: abundances of each species (in decreasing order)
rel.abund: relative abundances of each species (in decreasing order)
freq: frequency of each species (in decreasing order)

Details

Rank abundance curves or Whittaker plots (see Whittaker 1965) are used to display relative species abundance as biodiversity component. They are a means to visualize species richness and species evenness.

References

Whittaker, R. H. (1965). Dominance and Diversity in Land Plant Communities: Numerical relations of species express the importance of competition in community function and evolution. Science 147 : 250-260. doi:10.1126/science.147.3655.250

Author

Friedemann von Lampe (fvonlampe@uni-goettingen.de)

Examples

## Draw rank-abundance curve
racurve(schedenveg)

## Draw rank-abundance curve and label first 5 species
racurve(schedenveg, nlab = 5)


## Draw rank-abundance curve with log-scaled axis
racurve(schedenveg, ylog = TRUE)


## Draw rank-abundance curve with frequencies and no main title
racurve(schedenveg, frequency = TRUE, nlab = 1, main = "")