Results of the two-step fourth corner analysis (Pearson’s correlation coefficients) performed on Cytobuoy-derived phytoplankton traits and environmental variables.

<p>Significant correlations at <i>p</i>>0.05 are highlighted in bold (n = 22-groups × 15-sites × 15-traits). Corresponding p-values are reported in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071677#pone.0071677.s003" target="_blank">Table S3</a>.</p>a<p>First principal component of all traits, aggregated representation of phytoplankton morphology (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071677#pone.0071677.s001" target="_blank">Table S1</a>);</p>b<p>Length by SWS, the most accurate measure of particle length;</p>c<p>Total FL (integrated signal),</p>d<p>Maximum amplitude of FL;</p>e<p>Fill factor, between 0 and 1, gives information on how the signal resembles a square signal, i.e. very low values indicate that the signal is concentrated in a very narrow peak, indicative of an uneven distribution of pigments within cell/colony;</p>f<p>number of humps in the signal, proportional to number of cells for colonial phytoplankton or the number of FL peaks per particle.