We tested whether seedlings of four beech provenances, from contrasting edaphoclimatic environments, expressed differences in trait responses to imposed water stress under sun and shade treatments. Populations from the southern range margin were expected to display greater water-stress tolerance and core populations faster growth rates in the absence of abiotic limitations. Seedlings germinated under controlled conditions and were grown under controlled light-x-watering treatment combinations comprising shade/sun (main plot factor) and well-watered/water-limited (split-plot factor) groups. Beech seedlings remained under the experimental conditions from May through to September. Multiple sampling of growth (height, branching, number of leaves, leaf length, and root collar diameter), and leaves traits reflecting photosynthetic productivity and stress tolerance were made during the spring and summer. Leaf level gas exchange was measured by IRGA, leaf pigmentation by multiple optical sensors, leaf water potential with a pressure chamber, as well as plants and leaf morphological traits at the end of the experiment. Methods and Results are described in detail in the manuscript: Title: Seedlings from marginal and core populations of European beech (Fagus sylvatica L.) respond differently to imposed drought and shade. Authors: Fang Wang, David Israel, José-Alberto Ramírez-Valiente, David Sánchez-Gómez, Ismael Aranda, Pedro J Aphalo, T Matthew Robson. Files added are:"OverallData.xlsx" are the raw leaf level data collected in the experiment for the traits recorded, arranged in spreadsheets according to measurement type. Sheets are: "SoilMoistureRData", "PARData", "GasExchangeFigureData", "LeafObsData", "GrowthData", "LeafTraitsFigureData". "SummaryData.xlsx" are the individual replicate plot level summary data (calculated from the OverallData in R) for use in statistical analyses. Sheets are: "comparison", "GasExchangeSummary", "LeafTraitsSummary". "FMIradiation1hrData.xlsx" and "FMIradiation10minData.xlsx" Downloaded FMI irradiance data for the period of the experiment from Kumpula Meteorological Station (at 1hr and at 10 min interval), organised and arranged in spreadsheets: FMIradiation....xlsx files "Statistical Tables.docx" are summaries of the statistical tables calculated from the experimental data. "Statistics.zip" contains individual excel files showing the statistical analyses, least squared means, and pairwise comparisons for each analysed trait, plus the statistical code used to run these analyses. One file put trait- these files are summarised in "Statistical Tables.docx" "Plasticity Index.docx" show the results of calculated plasticity index for each of the traits measured, and details of how this calculation was performed.