Data from the journal article "Individual versus combined effects of warming, elevated CO2 and drought on grassland water uptake and fine root traits"

This data file contains all data used in the aforementioned article (DOI: 10.1111/pce.15274). The data was obtained in a long-term multifactor global-change experiment (‘ClimGrass’) in a managed (three cuts, fertilized) C3 grassland near the central European Alps in Styria, Austria (47°29′44.6″N, 14°5′54.6″E). Grassland plots were exposed to six treatments: (i) ambient conditions (control; n = 8); (ii) drought (n = 4); (iii) warming (n = 3); (iv) elevated CO2 (n = 3), (v) future conditions (warming and elevated CO2; n = 3); and (vi) drought in future conditions (warming, elevated CO2 and drought; n = 4). The experiment was conducted during the growing seasons of 2017, 2019, and 2020. The aim was to determine how warming, elevated CO2 and drought individually and interactively affected root water uptake (RWU, calculated from soil water dynamics) as well as the corresponding mass and key traits (specific root length (SRL); specific root area (SRA); mean diameter) of newly produced fine roots (extracted using ingrowth cores) and biomass allocation (fine-root-to-shoot production ratios; R/S ratios). Treatment effects on RWU were studied across varying conditions of soil water content (SWC) and vapour pressure deficit (VPD), referred to as dryness conditions. Fine root characteristics were compared to the maximum hourly in-situ RWU observed. 

The following data is contained in this file (processed as described in the journal article and, importantly, in the supplementary information):- data_SWC: SWC and precipitation, used to calculate RWU (resolution: hourly; figures: 1)- data_RWU_daily: RWU for the main rooting horizon, fractions of total RWU across depth (resolution: daily; figures: 1, 2, 3)- data_RWU_hourly: RWU for the main rooting horizon, SWC, VPD (resolution: hourly; figures: 1, 4, 5)- data_FineRoots: Mass, traits (SRL, SRA, diameter) and maximum hourly RWU of newly produced fine roots across depth, R/S ratios (resolution: three samplings per growing season; figures: 6, 7)

The metadata.xlsx file summarizes the contents of these datasets, including units and descriptions of the variables.

Note below: the name of the project funded by the Austrian Academy of Sciences is ClimGrassHydro.