Correlation between plant functional traits and chemical
diversity
The results of the coinertia analysis revealed a significant correlation
between the matrix of plant functional traits and the GSL matrix (Fig.
2; r = 0.49, p = 0.01), which grouped species according to common
habitat-driven growth forms and GSL diversity scheme. Group1 was
composed of species having higher chlorophyll levels, tough leaves, low
SLA and low herbivore damage, typical of alpine species (C.
alpina, C. resedifolia, C. rivularis , and C. amara ). Group 2 was
composed of species with high biomass, particularly of mid-elevation
forest species (C. kitaibelii, C. pentaphyllos, and C.
heptaphylla ). Group 3 was composed of species from mid-to-high
elevation species growing in grasslands or in forest edges (C.
trifolia and C. pratensis ). Group 4 was composed of species with
high SLA, low SPAD and high herbivore pressure, typical of low-elevation
inhabiting species (C. hirsuta, C. impatiens, C. flexuosa, C.
matthioli and C. bulbifera ) (Fig. 2 and Fig. 3). Scoring from
the LDA analysis highlighted that methoxyglucobrassicin and
glucobrassicin are the GSLs characteristic of group1, 2-methy-butyl-GSL
of group2, butyl GSL of group 3, and glucobrassicin and
hydroxyglucobrassicin of group 4 (Fig. 3, Table S3).