Table 4 Number of countries that record standing tree quality parameters, which can be used to assess stem quality, in the field or use the parameters for stem quality assessment or for generating assortments

Parameter

N

%^a

N

%^b

N

%^c

Tree status (dead, alive)

28

100

17

94

10

91

Tree dbh

28

100

18

100

11

100

Tree height

28

100

14

78

10

91

Stem damage

22

79

16

89

8

73

Tree break

21

75

15

83

8

73

Base of living crown

19

68

10

56

5

45

Stem damage source

18

64

13

72

5

45

Abiotic damage

18

64

13

72

4

36

Forking

18

64

13

72

7

64

Base of crown

18

64

9

50

5

45

Biotic damage

17

61

13

72

4

36

Splitting due to frost

17

61

12

67

7

64

Rottening

16

57

13

72

8

73

Splitting due to lightening

14

50

12

67

7

64

Stem cavity

13

46

11

61

6

55

Curvature

12

43

12

67

8

73

Straightness

12

43

12

67

8

73

Presence of fruiting body

10

36

10

56

6

55

Branching

10

36

10

56

5

45

Size of branches

8

29

9

50

5

45

Artificial removal of branches

8

29

4

22

1

9

Branching density

7

25

11

61

5

45

Upper diameter

7

25

4

22

6

55

Other

6

21

6

33

4

36

Bark thickness

5

18

4

22

4

36

Crown projection or diameter

4

14

2

11

3

27

Staining of discolouration on bark

3

11

6

33

2

18

Base of dead crown

3

11

3

17

2

18

Stem taper

3

11

6

33

4

36

Branch angle

2

7

2

11

1

9