Rank Abundance Plot

The rank abundance plot is used to show, and contrast, the number and relative abundances of species in a population.

The rank abundance plot shows the relative abundances of species on the Y axis in relation to ranks of the species abundance on the X axis. The most abundant species is ranked 1. Data points are connected by a line to produce a curve of relative abundance against rank.

To produce this plot, two or more variables must be selected from the list at the left side of the dialog. For analysis of species abundance data, these variables should be species (or higher-level taxonomic) identifiers, and the corresponding columns should contain abundances. Control-click and Shift-click combinations can be used to select multiple variables. At least two variables must be selected.

When more than one row is included in the data set used for the plot, the abundances in each column will be summed.

If a grouping variable is specified, multiple rank abundance curves will be displayed on the same plot, one for each group. The lines will be uniquely colored and a legend will display the color for each group.

Although developed specifically for analysis of species abundance data, a rank abundance plot can be used with other types of data, such as demographic data. The columns selected for use with the plot should all represent the same type of metric, for which summing produces an interpretable measure.