Graphical Analysis of Taxonomic Proportions of River Phytoplankton Communities in Moscow Megapolis

Abstract

The taxonomic composition of phytoplankton communities in the Moscow River was studied in the area of Moscow megapolis during 2006–2012. The basic regularities of spatial transformation of river phytoplankton were revealed. The main factors affected the phytoplankton structure are as follows: (1) wastewater inflow carrying nutrients and allochthonic phytoplankton, (2) abnormal high average monthly air temperature (26.1°С) in 2010. The principal regularities of changes in phytoplankton structure under the influence of these factors were established. To analyze the structural transformation we estimated the total number of species and abundance of phytoplankton, and also used the analysis of taxomonic structure of diatom complexes with and without taking into account rare taxa. In the area of the wastewater treatment facilities the species diversity is higher, and taxonomic structure of the phytoplankton community is violated. Natural decline in species diversity on account of dominance of species which are more adapted to natural hydrological conditions occurred at the river section not further than 34 km.