Form 5a - ICP Forests

Note: The assessment of the social class of a tree is in some cases difficult. Suppressed
trees should not be equated with dying trees as, in a mixed-age stand, they represent
future generations of trees. Classification on steep slopes presents a problem as even
relatively short trees may receive direct light from above. In such cases, classification
should be based on the relative heights of the trees.
(23) Crown shading D_SHADING
(Chapter 2)
Crown shading is assessed on a six-point scale as follows:
1 crown significantly affected (shading or physical interactions) on one side
2 crown significantly affected (shading or physical interactions) on two sides
3 crown significantly affected (shading or physical interactions) on three sides
4 crown significantly affected (shading or physical interactions) on four sides
5 crown open-grown or with no evidence of shading effects
6 suppressed trees
(24) Visibility D_VISIBILITY
(Chapter 2)
The following codes should be used for the assessable crown:
1 Whole crown is visible
2 Crown only partially visible
3 Crown only visible with backlighting (i.e. in outline)
4 Crown not visible
Note: Class 3 is distinguished from Class 4, as some parameters can still be assessed
when only back-lighting is present.
(25) Defoliation D_DEFOLIATION
(Chapter 2)
Defoliation is assessed in 5% steps. These classes are 0, 5 (>0-5%), 10 (>5-10%) and so
on. A tree with between >95% and 100% defoliation, which is still alive, is scored as 99.
The score 100 is reserved for dead trees (EC Regulation). Trees should be reported in
these 5% classes and not in aggregated groupings.
Code
defoliation score
0 0%
5 >0-5%
10 >5-10%
15 >10-15%
20 >15-20%
25 >20-25%
30 >25-30%
35 >30-35%
40 >35-40%
45 >40-45%
50 >45-50%
55 >50-55%
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