Combined approach of RLQ and fourth corner analysis. The fourth-corner analysis tests significance of bivariate associations between RLQ axes and traits/environmental variables. The significance level was alpha = 0.05.: (A) Representation of tests between the first two RLQ axes for environmental gradients (AxR1/AxR2) and species traits. (B) Representation of tests between the first two RLQ axes for trait conditions (AxQ1 and AxQ2) and environmental variables. The black lines separate environmental variables and white line separates modalities for categorical variables. Significant positive associations are represented in red, significant negative associations are represented in blue and, non-significant associations are represented in grey. (C) The significant associations with first axis are represented in blue, with second axis in orange and non-significant associations are represented in grey.