2.4 Environmental data
Site location data (latitude and longitude) were extracted from source publications. All climatic variables and soil properties were extracted from databases using the function ‘extract’ in R 4.1.3 (R Core Team, 2022) package RASTER (Hijmans et al ., 2015) (Table S1). We included 18 variables from WorldClim: mean annual temperature (MAT), seasonality of temperature (Ts), the highest and lowest temperatures of the warmest and coldest month (Tmax, Tmin), mean temperature of the wettest and driest (Twet, Tdry) and warmest and coldest (Twarm, Tcold) quarters, mean annual precipitation (MAP), seasonality of precipitation (Ps), the monthly precipitation of the warmest and coldest month (Pmax, Pmin), precipitation of the wettest and driest (Pwet, Pdry) and warmest and coldest (Pwarm, Pcold) quarters, mean diurnal range (MDR), and isothermality (ISO). We extracted potential evapotranspiration (PET) and aridity index (AI = MAP/PET) using global potential evapotranspiration (Global-PET) and aridity index (Global-Aridity) data sets (http://www.cgiar-csi.org). We also extracted potential hydrogen content of the soil (pH), total soil nitrogen concentration (SN), and total soil phosphorus concentration (SP) from the SoilGrid (https://www.isric.org/explore/soilgrids).