Discussion
Combining a multi-treatment greenhouse experiment with global-scale
field observations, we disentangled the main sources of intraspecific
trait variation for the short-lived herb Plantago lanceolata .
Expression of functional traits along environmental gradients in the
field was retained to some extent in the greenhouse, indicative of
population genetic differentiation. However, while reproductive traits
(biomass-corrected probability of flowering and fecundity) showed
similar effects of source environment across exposure treatments,
vegetative traits (biomass, specific leaf area and root:shoot ratio)
showed more plastic responses and some contrasting effects of source and
exposure environments. These results imply a higher predictability of
genetic differentiation from field observations in reproductive than
vegetative traits.