Pre-adaptation to climate change through topography-driven evolution of traits and their plasticity

Phenotypic data were collected in a glasshouse, in which Fragaria vesca plants originating from 11 locations were subjected to three episodes of three soil moisture treatments. The phenotypic variables include dried above-ground biomass, specific leaf area (SLA), the total number of runners produced during the second episode soil moisture treatment (counted and cut each week), number of stomata, and total number of flowers during a third episode of soil moisture treatments. SLA was measured for the most representative leaf per plant (i.e. average in size), as the ratio of “leaf area / dried leaf mass”. Stomata were counted on nail polish leaf prints using a KEYENCE light microscope at 1000 x magnification. For three replicate counts per leaf print, median stomatal density instead of averages were used to minimize the impact of counting errors. We did not measure stomatal size because image quality was insufficient for accurate size estimates. To disconnect runner and flower formation from growth, we divided runner and flower numbers by biomass. Thus, runnering and flowering were expressed per unit dry biomass (g). As a proxy for potential maternal effects, dry above-ground biomass was measured during the first soil moisture treatment (early growth).