Data for: Greater thermal plasticity toward heterogeneous range-edge environments of three <em>Hypericum</em> species

Intraspecific variation in phenotypic plasticity can affect the ability of populations, and thus species, to respond to environmental changes. However, the prevalence and drivers of such variation are not well known. Most proposed explanations for intraspecific variation in phenotypic plasticity involve mechanisms associated with a population’s position within the species’ geographic range or the environmental heterogeneity experienced by the population. To assess the effect of these two drivers, and their potential interaction, we use a combination of germination and greenhouse experiments to measure thermal phenotypic plasticity in traits ranging from germination probability to flower abundance in populations of three Hypericum species sampled across their European ranges. We then relate thermal plasticity to each population's position within the species’ range and to the environmental heterogeneity of the sampling site. Our results revealed that, while average thermal plasticity in s..., Study populations We acquired seeds of the three species from different parts of their native ranges, totaling 8 H. montanum, 18 H. perforatum, and 12 H. maculatum populations (after filtering as described in Section 2.5), either by collecting them in the field or acquiring seed accessions from European seed banks (Fig. 1, Table S1). The seeds were primarily collected between 2017-2021, with one H. perforatum population collected in 2007 and one H. montanum population collected in 1998. The seed material from seed banks and our field collections was collected according to ENSCONET guidelines (generally originating from at least 50 individuals; ENSCONET, 2009). For the self-collected material, seeds were sampled per mother plant, and an equal number of seeds from each mother were pooled for each temperature treatment. Germination experiments The seeds were cleaned from debris with an aspirator (Agriculex DB-1, column seed cleaner CB115009) before sowing. For each population, we sowed a m..., # Data for: Greater thermal plasticity toward heterogeneous range-edge environments of three *Hypericum* species Dataset DOI: [10.5061/dryad.r2280gbs0](https://doi.org/10.5061/dryad.r2280gbs0) ## Description of the data and file structure We studied the drivers of variation in thermal plasticity among the European populations of three *Hypericum* species. First, we quantified thermal plasticity in several traits ranging from germination to flower abundance using a combination of germination and greenhouse experiments. Then, we related the degree of this thermal plasticity to each population's position within range and the environmental heterogeneity of the sampling site. Any NA represents missing data. ### Files and variables Koivusaari_et_al.zip contains the following folders/filesCodeodHereere you find the code for the analysis and figures. * Step 1: Prepare germination experiment data * Step 2: Prepare greenhouse experiment data * Step 3: Model trait responses to temperature ..., ,