Temporal variation in the abundance of <i>P</i>. <i>rubescens</i> and <i>Microcystis</i> sp. estimated by microscopic cell counting and by the number of reads in our Illumina dataset (from October 2013 to November 2014).

<p>(a) Indicates the number of reads of <i>P</i>. <i>rubescens</i> and <i>Microcystis</i> sp. performed by Illumina MiSeq sequencing. DNA extracts from 4 sampling points were pooled before sequencing. Reads were normalized to the smallest sample (n = 67,012 reads) on the basis of bacterial sequences. (b) Indicates the temporal dynamics in <i>P</i>. <i>rubescens</i> and <i>Microcystis</i> sp. cell counts. Cell counts are expressed as the median values of the data collected at the four sampling points. * No sample available.</p

Vertical variation in <i>P</i>. <i>rubescens</i> and <i>Microcystis</i> sp. densities and the mixing depth (Z_m) in the center (St3) of the Hammam Debagh reservoir.

<p>Interpolated cyanobacteria densities were obtained using the Surfer Software (v. 7.0, Golden Software Inc.).</p

Spatio-temporal variation in chlorophyll-<i>a</i> concentrations under the surface and in <i>P</i>. <i>rubescens</i> and <i>Microcystis</i> sp. cell densities over the first 1 m in the subsurface of the lake at the four sampling stations.

<p>Interpolation was obtained with Surfer (v. 7.0, Golden Software Inc.).</p

Summary of the richness and diversity indices calculated after normalization to the smallest sample size (n = 1367 reads) (samples from July (n = 527) were not taken into account).

<p>Summary of the richness and diversity indices calculated after normalization to the smallest sample size (n = 1367 reads) (samples from July (n = 527) were not taken into account).</p

Principal component analysis (PCA) performed on the dataset collected from the surface layer during the whole study period.

<p>(a) Correlation of environmental parameters (blue arrows) with the first factorial plane defined by the two first axes. <i>P</i>. <i>rubescens</i> and <i>Microcystis</i> sp. cellular abundances were included in the analysis as supplemental variables. (b) Dispersion of the observations (black points) on the first factorial plane defined by the two first components of the analysis; samples are grouped by months in ellipses. Z_max: maximum depth; %O₂: oxygen saturation; Evap: evaporation; WT°C: water temperature; AT°C: air temperature; Z_eu: depth of the euphotic zone; Cond: conductivity; Z_m: mixing depth; Turb: water turbidity; TDS: total dissolved solids.</p

Geographical position of the Hammam Debagh reservoir and locations of the four sampling stations in the reservoir.

<p>Geographical position of the Hammam Debagh reservoir and locations of the four sampling stations in the reservoir.</p