Skip to main content

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)