Table 4 Variance importance of the climatic, stand, soil and topographic variables as well as the total, residual and percentage of the deviance explained by the boosted regression trees by forest type. In bold, the group of variables with the greatest variance importance

Whole data set

40

13

30

17

2.41

1.49

38

Subalpine and oromediterranean conifers

52

13

21

13

1.73

1.12

35

Mediterranean conifers

51

6

24

19

2.38

1.50

37

Macaronesian conifers

35

19

28

19

1.16

0.70

40

Deciduous broadleaves

36

21

31

12

1.87

1.16

38

Evergreen broadleaves

38

10

33

19

2.01

1.26

37

Macaronesian broadleaves

49

14

25

12

2.26

1.00

56

Mixed stands of conifers and broadleaves

32

10

34

24

2.30

1.22

47

Open woodlands

28

22

36

13

2.60

1.43

45

Productive plantations

38

14

37

12

1.69

1.12

34

Unclassified

36

12

35

17

2.63

1.66

37