Fig. 6. RDA plot showing the similarity among sites during the different seasons, based on the various community traits (metrics) with physico-chemical variables superimposed. This tri-plot describes 56.2 % of the variation in the data, where 38.6 % is displayed on the first axis and 17.6 % on the second axis. Only metrics of which more than 31 % is explained by the model and the 14 most significant variables are visualised.