Key plant traits affecting growth performance can differ among and within species, influencing competitive plant community dynamics. We determined the intra-specific variability of germination base temperature among 13 arable weed species and the seedlings’ early post-emergence relative growth rate among 21 species in climate chamber and green house experiments. Intra-specific variability was quantified with two seed populations (originating from contrasting climate in Germany & France) for the germination base temperature of 6 species and for the early growth rate of 16 species. Inter-specific variability for both traits was always higher than intra-specific variability. Within a given species, we found that germination base temperatures were higher in seeds stemming from colder climate populations. Seedling relative growth rates did not differ between seed populations. Models simulating weed growth should reflect these differences in germination traits among populations, especially when they are used for weed community assembly studies in a local to regional extent.

Please see the published article for materials and methods of the experiments.

The file contains the raw data used in the analyses and for producing the figures in manuscript and supplementary material. "Fig1_temperatures" contains daily measurements of air and soil temperatures from Dijon-Epoisses (France) and Rostock-Warnemünde(Germany). "Table3_Basetemperature_counts" contains all counts of germinated seeds during germination experiments, together with timing of the observations (given as time since start of the experiment). "RelativeGrowth_perPot" contains all information on the regressions fitted on leaf area measurements vs. thermal time since emergence for each plant in the experiment. The two tables relating to "Fig5" contain the typical date ranges of crop management measures  as well as typical emergence periods of important weeds in the regions of Rostock and Dijon. For more detailed information see the published article.