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

A very high orderliness of the phytoplankton assemblage taxonomic structure wasfound with the help of several approximation models. Rank-abundance, rank-frequencyand rank-size distributions of the whole assemblage were built using eight-yearmonitoring data of Lake Kinneret phytoplankton, describing its taxonomic structurevariability under conditions of extreme environmental impacts and under typicalconditions known from the previous period. Based on the high coefficient ofdetermination of the linear regression (r² > 0.9), the long-term log-linear rank distributionmodels were selected. The log-normal distribution produced by the scale-free metabolicweb seems to be promising as a possible explanatory model. While large-scale datasetsare necessary to discover such statistical regularities, the operational taxonomic unitmethodology can be helpful. Such an approach helps us distinguish between severaldiscussed statistical models and provide precise approximation parameters. Simple andexact models of this type can be valuable for theoretical ecology and aquatic monitoringaims.