Table 2.
Environmental variables used or not used in the model.
| Variable Type | Code (Unit) | Description | Variables Used in Modeling | ||
|---|---|---|---|---|---|
| E. sinica | E. intermedia | E. equisetina | |||
| Climatic variables | bio1 (°C) | Annual mean air temperature | √ | √ | √ |
| bio2 (°C) | Mean diurnal temperature range (max. temp–min. temp) | √ | √ | ||
| bio3 | Isothermality | √ | √ | √ | |
| bio4 (°C) | Temperature seasonality | √ | |||
| bio5 (°C) | Max temperature of warmest month | ||||
| bio6 (°C) | Min temperature of coldest month | ||||
| bio7 (°C) | Temperature annual range | √ | √ | ||
| bio8 (°C) | Mean temperature of wettest quarter | √ | |||
| bio9 (°C) | Mean temperature of driest quarter | ||||
| bio10 (°C) | Mean temperature of warmest quarter | ||||
| bio11 (°C) | Mean temperature of coldest quarter | ||||
| bio12 (mm) | Annual precipitation | √ | √ | √ | |
| bio13 (mm) | Precipitation of wettest month | ||||
| bio14 (mm) | Precipitation of driest month | √ | √ | ||
| bio15 (mm) | Coefficient of variation of precipitation | √ | √ | √ | |
| bio16 (mm) | Precipitation of wettest quarter | ||||
| bio17 (mm) | Precipitation of the driest quarter | √ | |||
| bio18 (mm) | Precipitation of warmest quarter | ||||
| bio19 (mm) | Precipitation of coldest quarter | ||||
| Srad (kJ· m−2·d−1) | Solar radiation | √ | √ | √ | |
| Vapr (hPa) | Vapor pressure | √ | √ | √ | |
| Soil variables | soil | Soil type | √ | √ | √ |
| clay1 | Topsoil Clay Fraction (0–30 cm) | √ | √ | ||
| clay2 | Subsoil Clay Fraction (30–100 cm) | √ | √ | ||
| sand1 | Topsoil Sand Fraction (0–30 cm) | √ | √ | √ | |
| sand2 | Subsoil Sand Fraction (30–100 cm) | ||||
| sq1 | Nutrient availability | √ | √ | √ | |
| sq2 | Nutrient retention capacity | ||||
| sq3 | Rooting conditions | √ | √ | √ | |
| sq4 | Oxygen availability to roots | √ | |||
| sq5 | Excess salts | √ | √ | √ | |
| sq6 | Toxicity | ||||
| sq7 | Workability (constraining field management) | ||||
| Topographical variables | Ele (m) | Elevation above sea level | √ | √ | √ |
| Slop (%) | Slope | √ | √ | √ | |
| asp (degrees) | Aspect | √ | √ | √ | |
“√” represents environment variables that are used during model execution.