Correspondence Canonical Analysis (CCA) performed on the sequencing results expressed as proportion of OTUs detected in the eight libraries constructed at T96 h (i.e. C, UV, T, TUV, C + N, UV + N, T + N, TUV + N treatments). Environmental variables are heterotrophic bacteria (Bact), picocynobacteria (Picocyan), viruses (virus), temperature (Temp), UVB radiation (UV), nutrient concentration (Nut). Phylogenetic groups are Trebouxiophyceae (Treb), Pyramonadales (Pyram), Mamiellophyceae (Mam), Cryptophyceae (Crypto), Prymnesiophyceae (Prym), Bacillariophyceae (Baci), pigmented Dinophyceae (Dino), Ichthyosporea (Ichthy), Cercozoa (Cerc), Acantharea (Acanth), Hyphochytrids (Hypho), Bicosoecida (Bico), Amoebophrya (Amoebo), Ciliates (Cili), Uncultured Alveolates (UnAlv). The Venn diagram illustrates the relative proportions of the variation in sequence data that could be associated with variation in biological, chemical and physical parameters from the eigenvalues calculated by the CCA.