Dataset DOI: 10.5061/dryad.cvdncjtj4

Description of the data and file structure

Summary

This dataset contains modern plant wax n-alkane concentrations and compound-specific stable isotope measurements (δ13C and δ2H) compiled from published studies and newly generated data from temperate Europe.

The dataset was assembled to quantify vegetation-dependent apparent hydrogen isotope fractionation and supports vegetation-corrected hydroclimate reconstructions presented in the manuscript (Supporting Information 2):

"Central Europe hydroclimate since the Younger Dryas inferred from vegetation-corrected sedimentary plant wax δ2H values" (Santos et al., 2026).

The dataset includes site metadata, plant functional type classifications, climate parameters, and isotope measurements used to calculate apparent fractionation factors and vegetation correction models.

Comments

"NA" represents missing or Not Applicable Values. Cells marked "NA" in the analytical columns (e.g., AC–BJ) indicate that the compound was either below the instrumental detection limit, not chromatographically resolved, or not detected in the sample. In columns P, T, U, and V, entries marked as "not applicable" indicate that the variable cannot be meaningfully assigned to that sample.

The archive contains:

- Modern_European_Plant_Wax_data_revised_Santos_et_al.__2026.csv (main file)
- README.md (this file)

General data description:

Contains the full compiled dataset including:

• Study-level metadata
• Site geographic information
• Climate parameters
• Plant taxonomy
• n-alkane concentrations
• δ13C and δ2H measurements
• Derived variables used in vegetation correction calculations

Variable Definitions

• sample_index - This index serves as a unique internal reference and does not contain chronological or other meaning

• study - Author(s) and year of the study(ies), see full references in Santos et al., 2026 main body

• doi - DOI (Digital Object Identifier) of the study source, "NA" indicates no DOI available

• country - Country where the sample was collected

• region - European region as defined as per the United Nations - https://unstats.un.org/unsd/methodology/m49/, last access September 21st, 2025

• koppen_class - Koppen-Geiger climate classification of the site, see manuscript for the reference

• biogeo_reg - Biogeographical region as defined by European Environment Agency: https://www.eea.europa.eu/en/analysis/publications/report_2002_0524_154909, last access September 21st, 2025

• lat / lon - Latitude / Longitude (decimal degrees)

• elev_m - Elevation (meters above sea level), provided by the study or obtained via Google Earth pro based on the provided coordinates or satellite imagery

• ecosystem - Broad description of the ecosystem type (e.g., forest, grassland, marsh), Information based on the study/authors description or satellite imagery

• mean_ann_temp_C - Mean annual temperature (°C), data was either provided by authors in the study or collected from the respective national meteorological services

• ann_prec_mm - Mean annual precipitation (mm), data was either provided by authors in the study or collected from the respective national meteorological services

• sample_type - Type of sample (e.g., leaf wax, soil)

• plant_type - General plant category used in this study: Grasses vs. Woody Plants. Here, herbs are classified as grasses, as grasses are more common in the dataset

• r_1000_gs30 - Relative humidity (%) at 1000 hPa -30-year mean (30yr_growing_season_Apr_to_Aug_means_up_to_observation_year, April-August growing seasons up to and including the observation year). Source: ERA5 reanalysis

• t2m_gs30 - 2m air temperature (K) -30-year mean(30yr_growing_season_Apr_to_Aug_means_up_to_observation_year, April-August growing seasons up to and including the observation year). Source: ERA5 reanalysis

• sp_gs30 - Surface pressure (Pa) -30-year mean (30yr_growing_season_Apr_to_Aug_means_up_to_observation_year, April-August growing seasons up to and including the observation year). Source: ERA5 reanalysis
  PFT | Plant Functional Type a acronym used can be seen below

• common_name - Common name of the plant

• family - Plant family

• sci_name - Species name

• photosyn_path - Photosynthetic pathway (C3, C4)

• environment - Habitat notes (terrestrial, aquatic, etc.). Information based in the study/authors description or satellite imagery

• comments - Additional Information found in the original studies, sample number or if averages were performed. Entries marked as "NA" indicate that no additional comments were recorded for that sample

• sampling_date - Best possible date when samples where collected, formate used when completed yyyy/mm/dd

• ext_method - Extraction method for lipids

• tle_solvent - Solvent used for extraction

• conc_n-C21_ug_g ... conc_n-C33_ug_g - Concentration of n-alkanes (μg/g)

• d13C_n-C25 ... d13C_n-C33 - δ13C values (‰, vs) and SdS

• d2H_n-C25_d ... d2H_n-C33 - δ2H values (%) and SDs

• ann_prc_d2H_OIPC - Annual precipitation δ2H for each site based on OIPC version 3.1: https://wateriso.utah.edu/waterisotopes/pages/data_access/oipc.html, last access September 21st, 2025

• eapp_n-C27 ... eapp_n-C31_OIPC - Apparent fractionation factors for n-alkanes based on ann.prc.d2H.OIPC, see formula used in manuscript main body

• R.C_n-C27 ... R.C_n-C31 - Relative Concentration [ex. R.C_n-C27=(SUM[R.C_n-C27+R.C_n-C29+R.C_n-C31]).

  Plant Functional Type (PFT) Classification

Acronyms used:

• GR = Grass (herbs or non-woody plants)
• WP = Woody Plants (trees and shrubs)
• TD = Tree – Deciduous – Dicot
• TC = Tree – Coniferous – Gymnosperm
• SD = Shrub – Deciduous – Dicot
• SE = Shrub – Evergreen – Dicot
• SC = Shrub – Coniferous – Gymnosperm
• HD = Herb – Dicot

Data Sources

Precipitation isotope data were obtained from the Online Isotopes in Precipitation Calculator (OIPC v3.1).

Growing season climatic variables (e.g., relative humidity, temperature, and surface pressure) were obtained from the ERA5 reanalysis dataset, the fifth generation ECMWF atmospheric reanalysis of the global climate, produced by the Copernicus Climate Change Service (C3S) at the European Centre for Medium-Range Weather Forecasts (ECMWF). For full details and access, see the Copernicus Climate Data Store (CDS).

All other data were compiled from published literature and are fully referenced in associated study (Santos et al., 2026)

Units and Standards

δ13C values are reported relative to VPDB.

δ2H values are reported relative to VSMOW.

All isotope values are expressed in per mil (‰).

n-alkane concentrations are reported in µg/g dry weight.

Notes

This dataset was used to parameterize vegetation-dependent apparent fractionation factors applied to sedimentary plant wax δ2H records of ROT21 sedimentary record (see Santos et al., 2026).

Access information

Other publicly accessible locations of the data:

Part of the data was derived from the following sources:

• Ardenghi et al., 2024; Eensalu et al., 2024; Gamarra & Kahmen, 2015; Hepp et al., 2020; Nelson et al., 2018, 2017; Ortiz et al., 2011; Sachse et al., 2009, 2006; Santos et al., 2022; Schäfer et al., 2016; Srivastava & Wiesenberg, 2018.