Panel A – 72 different habitats, Panel B – the Římov reservoir, a seasonal study. Redundancy analysis (RDA) showing only the significant parameters responsible for the distribution of the entire Polynucleobacter genus (labeled as PnecABCD); P. necessarius, (PnecC); the B-lineage of Polynucleobacter, (PnecB, representing P. difficilis and P. acidiphobus); Limnohabitans, (R-BT065) bacteria; and Methylophilus genus (MET1217). PPtot, total primary production; A250nm, absorption at 250 nm (DOC proxy); DRP, dissolved reactive phosphorus; PP1-2um, primary production in the 1-2 μm size fraction; chlA, chlorophyll a; temp., temperature; EPP, extracellular primary production; “lake” triangle represents pooled data for the station DAM and MIDDLE; “river” triangle represents data for the RIVER stations (see Methods section); n.s., not significant.