PHOTOGRAMMETRIC ENGINEERING
tained so far proved to be not too successful
as the cork trees usually occur mixed with
Mediterranean Pine and scrub vegetation, and
a more detailed delineation of type differences
proved to be difficult. Perhaps the relatively
small photo-scale of 1:25,000 was a handicap
in this respect and possibly better results
would be obtained with photographs made on
a larger scale.
WEST-GERMANY
In connection with previous reports the
following data can be given. During the
period 1956-1959 the area covered by aerial
photographs for forestry work only can be
specified as follows:
Bavaria 3.420 sq. km
Baden-W ürttemberg 9.630 sq. km
Hessen 280 sq. km
Rhineland Pfalz 100 sq. km
North-Rhine Westphalia 78 sq. km
Lower Saxon 610 sq. km
Total 14.118 sq. km
Also used was other photographic material
not taken solely for forestry purposes, so that
a total of about 17,000 sq. km were worked
out during this period by aerial photographs,
or approx. one-fourth of the total forest area
of West-Germany. The reason for this rela-
tively high percentage can be explained by the
fact that aerial photography is at present con-
sidered essential for the periodic revision of
management planning, which is made every
10 or 20 years.
Only 3095 of the work was done without
using aerial photography, particularly when
the percentage of forest cover was too low or
when no photographic material was available.
[t was possible with the use of air photographs
to reduce the terrestrial measurements of
new type boundaries to 109; of the area
which otherwise would have been necessary.
Therefore the extra cost in making aerial
photographs was in most cases compensated
by the saving in time and money which would
have been necessary for terrestrial surveys.
The scale of the photographs was normally
1:10,000; in addition smaller scale photogra-
phy was used, for instance 1:20,000 and
1:30,000. For the latter wide-angle cameras
are mostly used. Type of camera usually used
for forestry purposes was Zeiss 21/18 and
11.5/18 and Eagle IX. Panchromatic film was
mainly used in combination with special
filters. More experience with different film-
filter combinations seems to be desirable.
Some tests with colour films were made.
10
The compilation of forest maps was mostly
achieved by transferring the type boundaries
to existing cadastral maps by using a projec-
tion instrument. In mountainous areas a
more complicated instrument, such as the
Stereotop is normally used. Also under such
circumstances it was possible to make maps
on a 1:5000 scale with an acceptable accuracy
In some cases in the flat regions new maps had
to be prepared, particularly when no accurate
cadastral maps were available. Under such
circumstances mostly first-order instruments
were used such as the Stereoplanigraph and
the Wild A.8
JAPAN
[n 1952 the Japanese Government was
again allowed to use its own aircraft for mak-
ing aerial photographs. A rapid development
in aerial survey can be observed since that
time; this has contributed to the rapid devel-
opment of its application to Japanese for-
estry.
As a result the Forest Service issued in
1058 a revision for the survey methods in
State Forests. This revision was based mainly
on the introduction of modern air survey and
sampling methods in order to achieve better
management. The program entailed photo-
graphing a total area of 1} million ha of the
State Forest per year. The photographic scale
varies between 1:32,000 and 1:35,000 in the
northern part of the country, and from
1:20,000 to 1:25,000 in the South.
The main uses of the aerial photographs
are as follows:
1. For map construction of forest areas and
occasional revisions in the location of
compartment and sub-compartment
boundaries.
2. To determine timber volume based upon
stratified sampling.
3. Construction of aerial volume tables for
the main species.
4. For road location, determination of ex
ploitation classes and for recreation pur-
poses.
5. For practical use on the spot by the local
Forest Service.
The original negatives are kept by Forest
Headquarters. Photo prints are distributed to
the different Planning Sections and to the
local Forest Service.
In the private forests 3 million ha of forest
area are mapped every year. This work is
done partly with new photographs and partly
by old ones taken by the US Air Force before
1952. The utilization of air photos by private