TreeGOER Climatic Moisture Index Zone Distributions: Observations for 48,129 tree species across 7 Global Climatic Moisture Index Zones Derived via the FAO Penman-Monteith Reference Evapotranspiration (ET0) and the Modified Hargreaves-Thornton Equations

TreeGOER (Tree Globally Observed Environmental Ranges) is a database that documents the environmental ranges (minimum, maximum, median, mean and 5%, 25%, 75% and 95% quantiles) for 48,129 tree species and for 51 environmental variables, including 38 bioclimatic variables, 8 soil variables and 3 topographic variables. TreeGOER is available from the following Zenodo archives: https://doi.org/10.5281/zenodo.7922927. The TreeGOER ranges were calculated after cleaning occurrence records and standardizing species names with the WorldFlora R package to World Flora Online or the World Checklist of Vascular Plants for a global GBIF occurrence download of 44,267,164 occurrences (GBIF.org 2021 GBIF Occurrence Download https://doi.org/10.15468/dl.77gcvq). The process of compilation of TreeGOER with 30 arc-seconds global grid layers, two examples of BIOCLIM applications that investigated the effects of climate change on global tree diversity patterns and R scripts to repeat these analyses have been described by Kindt, R. (2023). TreeGOER: A database with globally observed environmental ranges for 48,129 tree species. Global Change Biology 29: 6303–6318. https://onlinelibrary.wiley.com/doi/10.1111/gcb.16914. This Zenodo archive documents the occurrence of the same previously compiled and cleaned observations for the TreeGOER across global raster layers (https://zenodo.org/records/21808912) that document the distribution of Climatic Moisture Index zones derived by two different methods of calculating Potential Evapotranspiration: The Global Aridity Index and Potential Evapotranspiration (ET0) Database (here: GAIPED) uses the FAO Penman-Monteith Reference Evapotranspiration (ET0) equation. Methods for developing version 3.0 of the GAIPED database are detailed by Zomer et al. (2022). Version 3.1 (July 2025) of GAIPED was used where a critical update was made. Envirem applies the modified Hargreaves-Thornton equations that were previously used to generate version 1.0 of GAIPED. These two layers can be downloaded from this Zenodo archive, also including distribution maps: Kindt, R. (2026). Global Climatic Moisture Index Zones Derived via the FAO Penman-Monteith Reference Evapotranspiration (ET0) and the Modified Hargreaves-Thornton Equations (Version version 2026.08) [Dataset]. Zenodo. https://doi.org/10.5281/zenodo.21808912 For each of the 48,129 tree species, the distribution is given for: Envirem: the number of observations in CMI zones derived via Envirem GAIPED: the number of observations in CMI zones derived via GAIPED Static: the number of observations that are in the same CMI zone derived via Envirem and GAIPED Code Zone Definition C1 Hyper-arid CMI < −0.95 C2 Arid −0.95 ≤ CMI < −0.8 C3 Semi-arid −0.8 ≤ CMI < −0.5 C4 Dry subhumid −0.5 ≤ CMI < −0.35 C5 Humid −0.35 ≤ CMI < 0 C6 Very humid 0 ≤ CMI < 0.5 C7 Extremely humid CMI ≥ 0.5 C-1 (NA) The CMI zone could not be determined C-0 (ANY) Number of observations with disagreement in zonation between Envirem and GAIPED Calculations to create this archive were done in the R 4.5.1 environment, using the terra package (Hijmans 2025, version 1.8-70) to extract the zone for each observation (the same package was used previously to create the raster layers that define the CMI zones). References Zomer, R.J.; Xu, J.; Trabucco, A. 2022. Version 3 of the Global Aridity Index and Potential Evapotranspiration Database. Scientific Data 9, 409. https://www.nature.com/articles/s41597-022-01493-1 Title, P. O., & Bemmels, J. B. (2018). ENVIREM: An expanded set of bioclimatic and topographic variables increases flexibility and improves performance of ecological niche modeling. Ecography, 41(2), 291–307. https://doi.org/10.1111/ecog.02880 Fick, S. E., & Hijmans, R. J. (2017). WorldClim 2: New 1‐km spatial resolution climate surfaces for global land areas. International Journal of Climatology, 37(12), 4302–4315. https://doi.org/10.1002/joc.5086 Kindt, R. (2023). TreeGOER: A database with globally observed environmental ranges for 48,129 tree species. Global Change Biology, 00, 1–16. https://onlinelibrary.wiley.com/doi/10.1111/gcb.16914 . Kindt, R. (2024). TreeGOER: Tree Globally Observed Environmental Ranges (2024.07) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.13132613 Hijmans, R. (2025). terra: Spatial Data Analysis. R package version 1.8-70, https://CRAN.R-project.org/package=terra . Kindt, R. (2026). Global Climatic Moisture Index Zones Derived via the FAO Penman-Monteith Reference Evapotranspiration (ET0) and the Modified Hargreaves-Thornton Equations (Version version 2026.08) [Dataset]. Zenodo. https://doi.org/10.5281/zenodo.21808912 The development of this archive was supported by Norway’s International Climate and Forest Initiative through the Royal Norwegian Embassy in Ethiopia to the Provision of Adequate Tree Seed Portfolio project in Ethiopia, by the Green Climate Fund through the IUCN-led Transforming the Eastern Province of Rwanda through Adaptation project and through the Readiness proposal on Climate Appropriate Portfolios of Tree Diversity for Burkina Faso, by the Bezos Earth Fund to the Bezos Quality Tree Seed for Africa in Kenya and Rwanda project and by the German International Climate Initiative (IKI) to the regional tree seed programme on The Right Tree for the Right Place for the Right Purpose in Africa.