https://doi.org/10.5061/dryad.xsj3tx9ps

The dataset contains flowering and seed production data from two greenhouse generations monitoring the phenology of Lactuca serriola collected before and after 44 years of climate change along a steep precipitation gradient in Israel. Seed production data is also available for the second greenhouse generation. 

• Evolution_of_flowering_phenology__Lactuca_code_Van_Deurs.Rmd contains the code for analysis and visualization of all main results and key figures and results from the germination trial study. 
• lac_first_gen_r.csv contains data from the first greenhouse generation which was conducted to remove maternal effects.
  • Generation: Time period when seeds were collected from the field (either 1976 or 2020)
  • Population: Population identifiers for each population (A-U)
  • Population.1: Population identifiers for each population (A-U)
  • Pot: The sample identifier containing the sample cohort, population and sample number for this greenhouse generation
  • Replicate_num: The number of replicates that also germinated from the same mother plant
  • block: The block in which the sample was grown
  • table: The table number on which the sample was grown
  • pots: Sample pot number
  • Germination_date: Date of sowing for the first greenhouse generation
  • time.of.flowering: Date of flowering.Empty values indicate that the individual did not flower in the experiment. 
  • y: Latitude where sample was collected
  • x: Longitude where sample was collected
  • Precipitation.group: The precipitation group to which the population belongs.  
•  lactuca_second_gen_r.csv contains data from the second greenhouse generation which also contains a drought treatment
  • Cohort: Time period when seeds were collected from the field (either 1976 or 2020)
  • Population.1: Population identifiers for each population (A-U)
  • Pot: The sample identifier containing the sample cohort, population and sample number for this greenhouse generation
  • Drought_treatment: 0 indicates control conditions and 1 indicates drought treatment
  • gen.pop: A combination of the cohort and population identifier
  • gen: Cohort (either 1976 or 2020)
  • pop: Population identifiers for each population (A-U)
  • pot_final: The position of the pot in the block (integer) 
  • Germination: Date of germination for the sample. Samples with empty germination data indicate the four samples for which germination date was not recorded. 
  • flowering.date: Date of flowering for the sample. X and NA values indicate samples that did not flower during the experiment. 
  • Seed.weight..g.: Weight of total seeds produced by the sample (g)
  • X50.seed.weight: Weight of 50 seeds from the individual plant (g)
  • Estimated.seed.number: Estimated total number of seeds produced based on seed weight and 50-seed weight
  • seed.number.round: Seed number rounded to the nearest whole seed
  • Block: Block where the sample was grown
  • SC..y: Indicates if the sample had senesced. NA values indicate samples which were clearly senesced at the end of the experiment. Where unclear, the samples were identified and noted whether signs of senescence were observed. 0 indicates the sample had not senesced at the end of the experiment, while 1 indicates the sample was senesced. 
  • y: Latitude where sample was collected
  • x: Longitude where sample was collected
  • Precipitation.group: The precipitation group to which the population belongs.  
  • Treatment: Control or drought treatment as a character. 
• ne_50m_admin_0_countries.zip contains shapefiles from Natural Earth for the study area. 
• ne_50m_admin_0_breakaway_disputed_areas.zip contains shapefiles for the disputed lands. 
• Lactuca_-_All_lactuca_coordinates.csv contains coordinates of the sampled populations
  • Cohort: Time period when seeds were collected from the field (either 1976 or 2020)
  • Population.comparision: Population identifier for the collected samples indicating which samples will be compared. 
  • Access.number: Identification numbers for samples requested from CGN, the Israel Seed Bank, and those given to the samples collected in 2020. 
  • Collection.date:  Date of seed collection if known (dd.mm.yyyy) or (yyyy)
  • Collection.site:  Information on collection site. NA values indicate missing information on collection site. 
  • y: Latitude where sample was collected to the greatest known precision
  • x: Longitude where sample was collected to the greatest known precision
• Germination_trial_1976.csv contains data from the germination trial for seeds grown from the 1976 ancestral line
  • Sample: Plant from which the seed was collected in the second greenhouse generation
  • Treatment: Indicates if the maternal plant was grown under control or drought conditions
  • sown.seeds: Number of seeds from the maternal plant sown in the petri dish 
  • germinated..29.01...30.01: Number of seeds that had germinated by 29.01.2025 or 30.01.2025. Empty values indicate no additional seeds germinated on this day. 
  • germinated..04.02.: Number of seeds that had germinated by 04.02.2025. Empty values indicate no additional seeds germinated on this day. 
  • germinated..10.02.2025.: Number of seeds that had germinated by 10.02.2025. Empty values indicate no additional seeds germinated on this day. 
  • Notes: Notes on the seed germination. Empty values indicate no notes on germination. 
  • Total: Total number of seeds that germinated
  • Percentage: Proportion of seeds out of the number sown that germinated in the trial period 
• Germination_trial_2020.csv contains data from the germination trial for seeds grown from the 2020 ancestral line. 
  • Sample: Plant from which the seed was collected in the second greenhouse generation
  • Treatment: Indicates if the maternal plant was grown under control or drought conditions
  • sown.seeds: Number of seeds from the maternal plant sown in the petri dish 
  • germinated..29.01...30.01: Number of seeds that had germinated by 29.01.2025 or 30.01.2025. Empty values indicate no additional seeds germinated on this day. 
  • germinated..04.02.: Number of seeds that had germinated by 04.02.2025. Empty values indicate no additional seeds germinated on this day. 
  • germinated..10.02.2025.: Number of seeds that had germinated by 10.02.2025. Empty values indicate no additional seeds germinated on this day. 
  • Notes: Notes on the seed germination
  • Total: Total number of seeds that germinated
  • Percentage: Proportion of seeds out of the number sown that germinated in the trial period

External climate raster data

The climate raster files used to generate maps and extract environmental variables are not redistributed in this Dryad dataset because their source licenses are not compatible with Dryad’s CC0 waiver.

WorldClim v2.1 bioclimatic variables

The standard WorldClim v2.1 bioclimatic variables at 2.5 arc-minute resolution, representing the period 1970–2000, were used to generate maps and extract climatic variables. The maps in this study used precipitation of the wettest month, annual precipitation, and annual mean temperature, however a correlation matrix of all variables is also examined in the code.

Source: https://www.worldclim.org/data/worldclim21.html

Historical monthly precipitation data

Historical monthly precipitation data were obtained from WorldClim historical monthly weather data at 2.5 arc-minute resolution. The analyses used the version available at the time of download, downscaled from CRU-TS 4.06 using WorldClim 2.1 for bias correction. The current WorldClim monthly weather page may point to a newer CRU-TS version.

Current WorldClim monthly weather page: https://www.worldclim.org/data/monthlywth.html

Archived CRU-TS 4.06 / WorldClim 2.1 precipitation files used for reproducibility: https://geodata.ucdavis.edu/climate/worldclim/2_1/hist/cts4.06/2.5m/

To reproduce the 1966–1975 precipitation files, download the 1960–1969 and 1970–1979 precipitation archives from the CRU-TS 4.06 / WorldClim 2.1 directory and subset the monthly rasters for 1966–1975. To reproduce the 2010–2019 precipitation files, download the 2010–2019 precipitation archive from the same CRU-TS 4.06 / WorldClim 2.1 directory. Users should place the downloaded raster files in the input directories expected by the analysis scripts. The scripts describe how the monthly precipitation rasters were processed and averaged for the relevant time periods.

Code/Software

Code used for analysis of flowering and seed production trends across the precipitation gradient and temporal cohorts. The included R Markdown includes all packages needed to run the script.