Table 1.

List of the 26 selected phototrophic species used to establish the periphyton.

Group	Species	Phylum	Growth rate constant (k) (OD685/h)	Maximum reached biomass (OD685)	Growth groups	Starting inoculum (cells mL−1)
A	Achnanthidium pyrenaicum	Bacillariophyta	0.016	0.161		125,000
	Cyclotella meneghiniana	Bacillariophyta	0.017	0.285		125,000
B	Gomphonema parvulum	Bacillariophyta	0.011	0.231	G1	75,000
	Gomphonema clavatum	Bacillariophyta	0.014	0.211	G1	75,000
	Synedra sp.	Bacillariophyta	0.014	0.195	G1	75,000
	Fragilaria crotonensis	Bacillariophyta	0.016	0.059	G2	125,000
	Fragilaria capucina	Bacillariophyta	0.033	0.048	G2	125,000
	Melosira sp.	Bacillariophyta	0.018	0.051	G2	125,000
	Cymbella cistula	Bacillariophyta	0.018	0.034	G3	133,000
	Tabellaria sp.	Bacillariophyta	0.007	0.142	G3	133,000
	Ulnaria ulna	Bacillariophyta	0.01	0.081	G3	133,000
C	Scenedesmus acuminatus	Chlorophyta	0.019	0.797	G1	65,000
	Chlorella vulgaris	Chlorophyta	0.009	0.735	G1	65,000
	Pediastrum boryanum	Chlorophyta	0.011	0.393	G1	65,000
	Merismopedia glauca	Cyanobacteria	0.009	0.747	G1	65,000
	Cyclotella meneghiniana	Bacillariophyta	0.018	0.285	G2	125,000
	Nitzschia palea	Bacillariophyta	0.025	0.197	G2	125,000
	Nitzschia vermicularis	Bacillariophyta	0.012	0.023a	G2	125,000
	Craticula accomoda	Bacillariophyta	0.019	0.191	G2	125,000
	Sellaphora minima	Bacillariophyta	0.025	0.198	G2	125,000
	Scenedesmus vacuolatus	Chlorophyta	0.017	0.536	G2	125,000
	Pediastrum duplex	Chlorophyta	0.021	0.660	G2	125,000
	Chamaesiphon polonicus	Cyanobacteria	0.007	0.526	G2	125,000
	Phormidium sp.	Cyanobacteria	0.022	0.295	G2	125,000
	Pseudanabaena galeata	Cyanobacteria	0.020	0.520	G2	190,000
	Botryococcus braunii	Chlorophyta	0.005	0.417	G3	300,000
	Craticula cuspidata	Bacillariophyta	0.007	0.066	G3	300,000

Species were assembled into groups A, B, and C, according to the order of addition to the community. Growth rate constant k (OD₆₈₅/h) and maximum reached biomass (maximum OD₆₈₅) were derived from optical density measurements at 685 nm (Supplementary Table 3). Growth groups: G1—fast growth and high biomass; G2—fast growth and low/intermediate biomass; G3—slow growth and low biomass. To ensure accurate grouping of species, growth rate constant k (cell number/h) and maximum reached biomass (maximum cell number) were additionally derived from CASY cell counter for most of green algae and diatom species (see Supplementary Table 4).

^aDue to its cell morphology resulting in inaccurate measurements with the spectrophotometer, N. vermicularis was included in the intermediate (G2) group based on the growth rate and maximum biomass measured by CASY cell counter (see Supplementary Table 4).