DOI: 10.16904/envidat.564
title: 10 years of intra-annual carbon isotopes in tree rings from 3 conifer species

description: The data consists of a collection of environmental data, tree-ring width and intra-annual δ13C measurements of tree rings of three conifer species (Pinus sylvestris, Picea abies, Abies alba), and the R scripts that were used to analyse the data. Data was collected at two pairs of north and south exposed sites in Switzerland, in the Eastern Grisons (Surava North and Surava South) and Central Valais (Buthan and Lens). 
Intra-annual δ13C measurements were obtained using the laser ablation technique, which involved 10 sequential shots per ring. Shot 1 represents the δ13C value at the start of the ring, while Shot 10 corresponds to the δ13C value at the end of the ring's formation. Overall, the datasets consist of 400 profiles and 4000 isotope measurements.
Environmental data was collected at each site over decade, from 2012 to 2023. Key environmental variables include temperature, vapour pressure deficit (VPD), and soil water potential (SWP). Precipitation data was obtained from the EOBS v29.0e dataset (https://www.ecad.eu/download/ensembles/download.php) from the closest grid point. All data was aggregated on an hourly to daily scale.
In addition to environmental data, dendrometer data was used to derive the onset days, beginning of growth for each site (Onset_days.Rds). The data captures the dynamic relationship between environmental factors, such as soil and air moisture, and tree physiological responses, as reflected in δ13C variation. This dataset provides insights into the intra-seasonal interactions between environmental conditions and tree physiology. We provide the scripts for the main analyses performed in the Vitali, V. et al. 2025 article listed below, including the correlation of the isotope intra-annual time series with environmental variables.
This dataset contains all data on which the publication listed below is based.
Please cite this paper together with the citation for the datafile.
description: Resource Title: EnviDat_v1.zip
 Size: 12526311 bytes
 Format: application/x-zip-compressed
 URL: https://www.envidat.ch/dataset/7be610ac-028a-4275-8f3c-ccef7f975c29/resource/b38e6655-7429-4477-a91c-204da196cc8b/download/envidat_v1.zip
 Description: Description of key files
- climate_arranged_day0.Rds – aligned climate data according to the onset day
- climate_raw.Rds – aggregated climate data into hourly estimates
- d13cAtmCorr.Rds – atmospherically corrected shot-level δ13C for each site and tree
- d13c_mean. Rds – atmospherically corrected shot-level δ13C for each site, averaged across individual trees.
- climate_VPD_soil.Rds – processed VPD and SWP data
- climate_smoothed_method_figure.Rds – climate data used for Figure 1
- df_max_day. Rds – calculated maximum day of year for all onset days
- "1 arrange climate according to day0.R" – R script to arrange climate data according to the onset day
- "2 dendroTools analysis and heatmaps.R" – R script to calculate heatmaps of daily correlations
- "3 cross-correaltion analysis.R" – R script to perform the cross-correlation analysis to obtain the maximal correlation coefficient for a range of potential end days
- "4 linear models.R" – R script to fit linear models between δ13C and VPD and SWP