planting, because they 
1ce of the bare spaces. 
taken up again. 
planning clearances, 
». When making visits 
n, and this is of great 
nditions to be studied. 
the areas under their 
try purposes and are 
ys such as to locate 
2 
Je 
‘oo old for the dif- 
nd at the time of 
' before a general 
historical interest. 
recently, and the 
therefore not vet 
t not, if possible, 
| ten years old, are 
1 trees of different 
vood of the Medi- 
ising variation of 
29 
U. S. A.: 
This is an economic study. For a going lumber company that has its 
own plane an annual flight is made and obliques taken to bring cut over 
areas up to date. For a national inventory some pictures are used that are 
12 years old. 
Question No. 10: 
Has terrestrial photogrammetry been used (examination of stem-form or 
increment )? 
Austria: 
Terrestrial photogrammetry is not used to examine stem- or crown-form. 
Finland: 
Terrestrial stereoscopic photographing of stands was recently tried in 
Finland, but the methods have thus far not been added to the technique 
of taking aerial pictures. 
Germany: 
Ground photogrammetry is used for protection against erosion damages 
in large areas and to measure timber-volume (single scientific work). 
Italy and Sweden 
have answered this question in the negative. 
U. S. A: 
»No. Photos are not good enough for this as yet.» 
Question No. 11: 
Investigation and research regarding forest photogrammetry. Organiza- 
tion. Financial questions. 
Finland: 
The lack of grants of money for the purpose has made it necessary 
to put the technique of aerial photographing directly into practice without 
detailed examination. The only exceptions are the examination- and 
training-works mentioned above. 
Germany: 
Founding of an organization for collaboration in forestry photogram- 
metry at the Technical Centre of German forestry in Hamburg (Techni- 
sche Zentralstelle der deutschen Forstwirtschaft).