470 
Photo 1. Computer classification of a severely damaged 
spruce-fir stand near Bad Peterstal, 300 m altitude. 
For better presentation spruce was not divided in 
different damage classes. 
red: 
spruce 
green: 
fir healthy 
yellow: 
fir damaged 
blue: 
fir severely damaged 
orange: 
aeciduos trees 
white: 
roads, glades 
black: 
shadow 
Photo 2. Digital crown map for checking the classi 
fication. 
Same colours like Picture 1 only 
violett: spruce damaged 
red: spruce severely damaged 
Picture 1. Results of forest damage classification using ground check, 
CIR-Photointerpretation and multispectral scanner data 
frcm different altitudes 
□ S0/S1 healthy 
52 damaged 
53 severely damaged 
In table 4 examples of the analysis of a classifica 
tion are given for differently damaged firs. 
Table 3. Classification of forest damage classes used 
throughout Germany 
SO-1 
52 
53 
54 
less than 25% needleloss 
26 to 60% needleloss 
more than 60% needleloss 
dead 
(healthy - sickly) 
(damaged) 
(severe damaged) 
Table 4. Example for differently damaged firs (tree 
#1 to #3 damage class S2, tree #4 to #6 darhage class 
S3). Results are given in percent of classified pixels 
per tree crown. 
Stand A Stand B 
tree 
SO-1 
S2 
S3 
misclassi- 
average damage 
100 
number 
fied 
class rating 
1 
60 
23 
17 
0 
1,5 
90 
2 
57 
23 
16 
4 
1,8 
80 
3 
44 
19 
16 
21 
1,6 
4 
18 
19 
39 
24 
2,3 
c 70 
5 
23 
24 
37 
16 
2,1 
8 60 
6 
26 
31 
23 
20 
2,0 
From this altitude a damaged tree crown contains up 
to 100 pixels which can belong to any given damage 
class. For example a fir with approximately 50% 
needleloss will be classified as healthy in the top 
of the crown where it seems to be green and healthy, 
the lower branches which show some needleloss and 
discoloration, will be classified as sick and the part 
of the crown which is defoliated, will be classified 
as severely damaged or dead. The degree of misclassi- 
fied pixels will also increase with the damage degree 
because more shadow, soil or ground vegetation re 
flects through the defoliated crown and increases the 
mixed signatures. The situation is the same when other 
species are evaluated. 
£ 20 
m 
i 
i 
Stand A: Old spruce stand mixed with fir; severely damaged 
with low density 
Stand B: Old spruce stand severly damaged and partly snow 
breakage 
Stand C: Young spruce stand with snow breakage 
Stand D: Yeung spruce stand