*4.1. Methods of Plotting Species Abundance Data*

4.1.1. Whittaker Plot

One of the best informative methods is the rank/abundance plot, or dominance diversity curve. Here, species are plotted from most to least abundant along the *x* axis and abundance in the *y* axis in log10 format (here, abundance of several orders of magnitude can be accommodated in the same graph). Proportional or percentage abundance are used in order to facilitate easy comparison.

The authors of [9] named this plot the Whittaker plot in remembrance of R. H. Whittaker for his famous contribution described in [10]. This plot has several advantages. Contrasting patterns of species richness are clearly displayed. If there are only a few of some species, all the information concerning their relative abundance is visible, as they are represented in their histogram format (see [11]). For following environmental impacts and succession, this plot is very effective. For that, we should plot a rank/abundance graph. The shape of the curve gives inference about which species abundance model best fits the data. The steep plot describes assemblages with high dominance, while the shallower plot symbolizes low dominance. High dominance plots are consistent with geometric or log series, while low dominance plots suit the log normal or broken stick model. However, the curves of different models are rarely fitted with empirical data (see [11]).
