Fig. 4.

Nitrophily is the most influential ecological trait in defining the first component of the PCA. This attribute accounts for around half of the variation in data for plants’ LnBR values. Specifically, in the shoot and roots, this first component explains 51% and 44% of the variation, respectively, while the second component accounts for 21% and 25%. The soil pH (‘R’) is displayed through a color scale, while the plot size indicates fertility and nitrogen (‘N’) preferences based on the Ellenberg index.