Effects of environmental drivers in field populations
Trait variation for in situ field populations was associated with
both environmental drivers and biogeographic range (native vs.
non-native) in the best models, although their effects did not interact
in most cases (see blue lines in Fig. 5; Table S4; Fig. S7-S9). Biomass
was positively correlated with Vegetation Cover and Mowing, and was
higher in non-native populations (Fig. 5a). SLA did not differ between
ranges, although we found an interaction between Temperature and
biogeographic range, whereby SLA decreased with increasing Temperature
in the native but not the non-native range (Fig. 5b). Biomass-corrected
probability of flowering was affected negatively by Vegetation Cover and
positively by Mowing, and was lower in non-native populations (Fig. 5c).
Biomass-corrected fecundity was positively affected by Aridity and
Temperature, and the effect of Aridity was stronger in the native than
the non-native range (Fig. 5d). When biomass was excluded as a covariate
from the analyses, the best model of probability of flowering lost the
effects of Vegetation Cover and Range, and the best model of fecundity
incorporated the effects of Mowing and the interaction between Range and
several source drivers (Table S8). Non-native populations showed
significantly higher temperature and seasonality of moisture index than
native populations, and lower values in moisture index (Table S9).