The climatic water content is calculated as previously described [1, 2] using the average number of consecutive dry days obtained from precipitation timeseries (MSWEP [3]), potential evapotranspiration [4] (based on WorldClim [5]) and soil information (SoilGrids [6]). The maps are generated at 0.1° resolution with a global extent of -180 to 180 °E and -60 to 90 °N. References [1] Bickel, Samuel, Xi Chen, Andreas Papritz, and Dani Or. “A Hierarchy of Environmental Covariates Control the Global Biogeography of Soil Bacterial Richness.” Scientific Reports 9, no. 1 (August 20, 2019): 1–10. https://doi.org/10.1038/s41598-019-48571-w. [2] Bickel, Samuel, and Dani Or. “Soil Bacterial Diversity Mediated by Microscale Aqueous-Phase Processes across Biomes.” Nature Communications 11, no. 1 (January 8, 2020): 1–9. https://doi.org/10.1038/s41467-019-13966-w. [3] Beck, Hylke E., Eric F. Wood, Ming Pan, Colby K. Fisher, Diego G. Miralles, Albert I. J. M. van Dijk, Tim R. McVicar, and Robert F. Adler. “MSWEP V2 Global 3-Hourly 0.1° Precipitation: Methodology and Quantitative Assessment.” Bulletin of the American Meteorological Society 100, no. 3 (March 2019): 473–500. https://doi.org/10.1175/BAMS-D-17-0138.1. [4] Jensen, M. E., and H. R. Haise. “Estimating Evapotranspiration from Solar Radiation.” Proceedings of the American Society of Civil Engineers, Journal of the Irrigation and Drainage Division 89, no. 0023 (1963): 15–41. [5] Fick, Stephen E., and Robert J. Hijmans. “WorldClim 2: New 1-Km Spatial Resolution Climate Surfaces for Global Land Areas: New Climate Surfaces for Global Land Areas.” International Journal of Climatology 37, no. 12 (October 2017): 4302–15. https://doi.org/10.1002/joc.5086. [6] Hengl, Tomislav, Jorge Mendes de Jesus, Gerard B. M. Heuvelink, Maria Ruiperez Gonzalez, Milan Kilibarda, Aleksandar Blagotić, Wei Shangguan, et al. “SoilGrids250m: Global Gridded Soil Information Based on Machine Learning.” PLOS ONE 12, no. 2 (February 16, 2017): e0169748. https://doi.org/10.1371/journal.pone.0169748.