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Table 2 Environmental variables considered potential predictors for the distribution and productivity models

From: Predicting current and future suitable habitat and productivity for Atlantic populations of maritime pine (Pinus pinaster Aiton) in Spain

Type Abbreviation Description Unit Source
Terrain SLP Slope based on a digital elevation model % PNOA Lidar
ASP Aspect based on a digital elevation model °
CU Curvature  
PLC Plan curvature  
PRC Profile curvature  
TSI Terrain shape index  
WI Wetness index  
DHN Euclidean distance to nearest hydrographic network (m m
Climate BIO1 Annual mean temperature °C WorldClim
BIO2 Mean diurnal range (Mean of monthly (max temp - min temp)) °C
BIO3 Isothermality (BIO2/ BIO7) (*100) %
BIO4 Temperature seasonality (standard deviation *100) %
BIO5 Max temperature of warmest month °C
BIO6 Min temperature of coldest month °C
BIO7 Temperature annual range (BIO5- BIO6) °C
BIO8 Mean temperature of wettest quarter °C
BIO9 Mean temperature of driest quarter °C
BIO10 Mean temperature of warmest quarter °C
BIO11 Mean temperature of coldest quarter °C
BIO12 Annual precipitation mm
BIO13 Precipitation of wettest month mm
BIO14 Precipitation of driest month mm
BIO15 Precipitation seasonality (coef. of variation) %
BIO16 Precipitation of wettest quarter mm
BIO17 Precipitation of driest quarter mm
BIO18 Precipitation of warmest quarter mm
BIO19 Precipitation of coldest quarter mm
Sr_ss Solar radiation in summer solstice kJ m2 year−1 PNOA Lidar
Sr_eq Solar radiation in equinox kJ m2 year−1
Sr_ws Solar radiation in winter solstice kJ m2 year−1
Soil SC Soil organic carbon content mG/ha SoilGrids250
pH_H2O Soil pH in H2O solution  
pH_KCl Soil pH in KCl solution  
BD Bulk density of fine earth fraction (< 2 mm) kg m−3
CLAY Percentage of clay in soil Weight %
SAND Percentage of sand in soil Weight %
SILT Percentage of silt in soil Weight %
CF Coarse fragments Volumetric %
CEC Cation-exchange capacity cmol + kg−1
DB Absolute depth to bedrock cm
DB200 Depth to bedrock (R horizon) up to 200 cm cm
R Probability of occurrence of R horizon within 200 cm %
SC_fef Soil organic carbon content (fine earth fraction) g
Geo_units Geochronological units   SGM
Geo_lit_units Lithological units  
LIT_dco Hydrogeology   SSM
LIT_dlo Lithostratigraphy  
LIT_per Lithostratigraphy permeability  
WRB-FULL Full soil code of the Soil typological units from the World Reference Base (WRB) for soil resources   ESDB
WRB-LEV1 Soil reference group of the soil typological units from the World Reference Base (WRB) for Soil Resources  
  1. SGM Spanish geological map (1:1000,000), SSM Spanish stratigraphic map (1:200,000), ESDB European soil database v2.0 (1:1000,000)