Results
πtlp was considerably more negative in graminoids than in forbs (one-way ANOVA; F1,120 = 26.86, P< 0.001; Fig. 1a). LDMC was significantly higher in graminoids than in forbs (one-way ANOVA; F1,120 = 87.66, P< 0.001; Fig. 1b). There was no difference between the PFTs in their SLA values (one-way ANOVA; F1,120 = 2.72, P= 0.1; Fig. 1c). Graminoids were significantly taller than forbs (one-way ANOVA; F1,120 = 33.41, P < 0.001; Fig. 1d). No difference was observed in the δ13C values (one-way ANOVA; F1,52 = 0.004, P = 0.95; Fig. 1e).
πtlp was strongly negatively related to LDMC (more negative πtlp, i.e. higher leaf-level dehydration tolerance, was coordinated with higher LDMC) and to δ13C (more negative πtlp coordinated with less negative δ13C, i.e. higher intrinsic water-use efficiency) on all levels: (a) when considering all species together (Table 1a, Fig. 2a,e), (b) within the plant functional types with the slopes of the relationships being not significantly different (Table 1b, Fig. 2a,e), (c) as well as after accounting for phylogenetic relatedness (Table 1c, Fig. 2b,f).
The positive relationship between πtlp and SLA (more negative πtlp coordinated with lower SLA) only emerged weakly for forbs (Table 1b, Fig. 2c) and then more strongly after accounting for phylogenetic relatedness (Table 1c, Fig. 2d). πtlp was weakly negatively related to vegetative height (more negative πtlp coordinated with taller species) when all species were considered together (Table 1a, Fig. 2g). However, the relationship disappeared completely within PFTs (Table 1b, Fig. 2g), as well as after accounting for species phylogenetic relatedness (Table 1c, Fig. 2h).