Table 1.
Bioclimatic and soil variables used in the study (Hutchinson et al., 2009; Kriticos et al., 2014; Hengl et al., 2017).
| Variable number | Variable |
|---|---|
| Bio01 | Annual mean temperature (°C) |
| Bio02 | Mean diurnal temperature range [mean(period max–min)] (°C) |
| Bio03 | Isothermality (Bio02/Bio07) |
| Bio04 | Weekly temperature seasonality (C of V) |
| Bio05 | Maximum temperature of the warmest week (°C) |
| Bio06 | Minimum temperature of the coldest week (°C) |
| Bio07 | Annual temperature range (Bio05–Bio06) (°C) |
| Bio08 | Mean temperature of the wettest quarter (°C) |
| Bio09 | Mean temperature of the driest quarter (°C) |
| Bio10 | Mean temperature of the warmest quarter (°C) |
| Bio11 | Mean temperature of the coldest quarter (°C) |
| Bio12 | Total annual precipitation (mm) |
| Bio13 | Precipitation of the wettest week (mm) |
| Bio14 | Precipitation of the driest week (mm) |
| Bio15 | Weekly precipitation seasonality (C of V) |
| Bio16 | Precipitation of the wettest quarter (mm) |
| Bio17 | Precipitation of the driest quarter (mm) |
| Bio18 | Precipitation of the warmest quarter (mm) |
| Bio19 | Precipitation of the coldest quarter (mm) |
| Bio20 | Annual mean radiation (W m-2) |
| Bio21 | Highest weekly radiation (W m-2) |
| Bio22 | Lowest weekly radiation (W m-2) |
| Bio23 | Annual mean moisture index |
| Bio24 | Highest weekly moisture index |
| Bio25 | Lowest weekly moisture index |
| Bio26 | Weekly moisture index seasonality (C of V) |
| Bio27 | Mean moisture index of the wettest quarter |
| Bio28 | Mean moisture index of the driest quarter |
| Bio29 | Mean moisture index of the warmest quarter |
| Soil 1 | Depth to bedrock (R horizon) up to 200 (cm) |
| Soil 2 | Absolute depth to bedrock (cm) |
| Soil 3–Soil 6 | Bulk density (fine earth) (kg/m3) |
| Soil 7–Soil 10 | Clay content [0–2 μm mass fraction (%)] |
| Soil 11–Soil 14 | Coarse fragments volumetric fraction (%) |
| Soil 15–Soil 18 | Silt content [2–50 μm mass fraction (%)] |
| Soil 19–Soil 22 | Sand content [50–2,000 μm mass fraction in (%)] |
| Soil 23–Soil 26 | Cation exchange capacity of soil (cmolc/kg) |
| Soil 27–Soil 30 | Soil organic carbon content (fine earth fraction) (g/kg) |
| Soil 31–Soil 34 | Soil pH × 10 in H2O |
| Soil 35–Soil 38 | Soil pH × 110 in KCl |
The soil variables 3–38 describe the soil conditions at the following four respective soil layers: 0–15, 15–30, 30–60, and 60–100 cm.