COMMISSION VII: INTERPRETATION OF VEGETATION 
pulp and paper companies is increasing every 
year. 
JUGOSLAVIA 
As a result of the great importance of ap- 
plying aerial photography in Jugoslavian 
forestry, special arrangements are made at 
the Geodetic Department of the University in 
Zagreb for a short course in fundamental 
photogrammetry and photo interpretation 
techniques. These courses are mostly given 
during summer time. The object is to give 
specialists who are interested in the applica- 
tions of aerial photography, the opportunity 
to obtain a better training in its use in forestry 
and for, agricultural purposes. In addition, 
special courses are given for students of the 
Agricultural Department of the University in 
fundamental photogrammetry. 
Furthermore it is known that in this coun- 
try a beginning has already been made in the 
practical application of aerial photography 
to forestry, for instance the construction of 
forest maps, the identification of different 
forest types, differentiation according to site 
classes, the study of problems in plant soci- 
ology and for the area determination of arable 
land in the Karst regions. 
The photographic scale used for these pur- 
poses varies between 1:10,000 and 1:15,000. 
If such scales are not available other scales 
(1:20,000) are used. All photographs are 
made with panchromatic film; interpretation 
results are not always satisfactory. 
THE NETHERLANDS 
Training possibilities. As in preceding 
years a special course was given at the ITC 
in Delft dealing with the application of aerial 
photographs in forestry. In recent years, ın 
addition to indoor-training, importance was 
attached to giving the students the oppor 
tunity to carry out field work. The forest re- 
gions selected for this purpose were situated 
in Austria and Switzerland. In the coming 
year a forest area in Germany will be selected. 
During the field work the student has the op 
portunity to check his interpretation work 
done in the office and to collect all further in 
formation necessary for compiling a forest 
type map of the region. The final results are 
afterwards worked out as a report to be sub- 
mitted at the end of the course. 
The scale of the aerial photographs used 
for this purpose varies between 1:20,000 and 
1:10,000. Provisional results obtained so far 
indicate that large-scale photography (say 
scale 1:10,000) is preferable to smaller scales. 
Particularly when the local forest contains 
numerous stand-types, as is mostly found in 
Switzerland, large-scale photographs proved 
to be very necessary. If no large-scale pho- 
tography was available, enlargements also 
gave satisfactory results. During the field 
check there is the opportunity to make com- 
parative tests of interpretation results ob- 
tained from different scales and film-filter 
combinations. Also the result of different 
printing methods can be ascertained. 
Different methods of map compilation are 
afterwards used in the office. Transfer of de- 
tail from the photographs to the map is 
mostly done by Sketchmaster. The instru- 
ment constructed by Zeiss is normally pre- 
ferred above other types such as Abrams and 
Fairchild. The use of the Sketchmaster 1s 
specially recommended when detailed and 
reliable forest maps are available, and further 
when the local differences in the elevation are 
relatively small. In pronounced mountainous 
regions the Radial Line Plotter proved to be 
the most suitable instrument. 
Forest management planning. Aerial photo- 
graphs are used by the State Forest Service 
for the compilation and periodical revision of 
management plans. Aerial photographs used 
for this purpose have scales varying between 
1:20,000 and 1:10,000. Photographs are 
mainly used as a guide to identifying and 
delineating stand differences. During this 
work, which is mainly executed in the field, 
other data such as occasional forest roads and 
drainage ditches are also indicated on the 
photographs. This information is afterwards 
transferred to the map by means of a projec- 
tion instrument. 
National Forest Inventory. To obain basic 
information regarding general forest condi- 
tions over the whole country, a general forest 
inventory has been started, based upon the 
study of aerial photographs. In addition to 
information on the condition of the forests, 
data are collected dealing with waste land. 
The scale of the photographs used for this 
purpose is 1:20,000. Upon these photographs 
stand boundaries are delineated and are 
afterwards tranferred to the topographical 
map 1:25,000. Mapping results are after- 
wards checked in the field and at the same 
time volumes are determined. 
Preservation of natural vegetation and wild- 
life. Nowadays in this country aerial photo- 
graphs are also used with much success to ob- 
tain more profound information on the living 
conditions of rare plants and animals. Their 
particular environment is usually known and 
if this can be detected on the aerial photo- 
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