Table 1 Contribution of environmental variables used for modelling the potential distribution of S. regelii and S. sewerzowii

bio7

Temperature Annual Range (BIO5-BIO6), °C

60

0.4

bio8

Mean Temperature of Wettest Quarter, °C

0.3

0.9

bio17

Precipitation of Driest Quarter, mm

1.6

14.6

bio19

Precipitation of Coldest Quarter, mm

9.3

35.1

elev

Elevation, m

-

3.7

srl

Average solar radiation in a quarter with lowest solar radiation, W/m2

0.2

30.7

srh

Average solar radiation in a quarter with highest solar radiation, W/m2

22.1

-

cec

Cation Exchange Capacity of soil, cmolc/kg

2

0

ocs

Soil organic carbon stock, t/ha

1.2

0.2

pH

pH index measured in water solution

0.7

0.1

crf

Volumetric percentage of coarse fragments (> 2 mm), %

2.6

5.6

snd

Weight percentage of sand particles (0.05–2 mm), %

-

8.7