High orderliness of phytoplankton taxonomic structure as revealed by several approximation models

A very high orderliness of the phytoplankton assemblage taxonomic structure was found with the help of several approximation models. Rank-abundance, rank-frequency and rank-size distributions of the whole assemblage were built using eight-year monitoring data of Lake Kinneret phytoplankton, describing its taxonomic structure variability under conditions of extreme environmental impacts and under typical conditions known from the previous period. Based on the high coefficient of determination of the linear regression (r² > 0.9), the long-term log-linear rank distribution models were selected. The log-normal distribution produced by the scale-free metabolic web seems to be promising as a possible explanatory model. While large-scale datasets are necessary to discover such statistical regularities, the operational taxonomic unit methodology can be helpful. Such an approach helps us distinguish between several discussed statistical models and provide precise approximation parameters. Simple and exact models of this type can be valuable for theoretical ecology and aquatic monitoring aims.