PHOTOGRAMMETRIC ENGINEERING 
Etronic printer improves interpretation. 
The results of these studies can be expected 
to be published very soon. 
Comparable studies were also made at the 
Pacific Northwest Forest Experiment Station 
in Oregon. Research work was there carried 
out to ascertain the value of large-scale pan- 
chromatic and color photography for forest 
inventory purposes. Special objectives were: 
to determine the range of photo-scales that 
can be taken with currently available 
equipment; 
to determine the effect of photo-scale on 
the accuracy of species determination 
and the measurement of tree height, 
crown density and tree count; 
to determine whether any such increase in 
interpretation accuracy is sufficient to 
pay for the cost of the photography on a 
sample basis; 
to compare the accuracy of color and pan- 
chromatic photos for species identifica- 
tion and tree height measurement. 
Besides this the research work dealing with 
applying aerial photographs in the identi- 
fication of insect infestations has been con- 
tinued. This research work was carried out at 
the Forest Insect Beltsville, 
Maryland, and at the Pacific Northwest Sta- 
tion in Oregon. At the latter special attention 
was given to infestations in the following tree 
species: Ponderosa Pine, and 
Engelmann Spruce, being the predominant 
tree species in the forests of the Pacific 
Northwest region. The results obtained at 
both research stations can be found in pub- 
Laboratories at 
Douglas fir 
lications published recently. 
Finally special reference can be made to a 
publication to be issued by the Intermoun- 
tain Forest and Range Experiment Station in 
Utah. This will be published in the form of a 
Training Manual for Photo Interpreters. In 
this Manual a number of typical examples of 
forest interpretation problems are developed, 
which could be of interest for practical photo 
interpretation in general, but which are also 
important for certain training institutes deal- 
ing with interpretation problems. 
ARGENTINE 
In close cooperation with the Geographic 
Department of the Army and the Topo- 
graphic Institute, the Forestry Department 
of this country started with a survey of a 
total area of 966.400 ha, which was distri- 
buted as follows: in the province of Misiones 
217.400 ha, in Chaco 260.000 ha and in 
Formosa 489.000 ha. 
14 
The photographic material such as the 
original photographs, photographic coordi- 
nates, flight indices and in some cases even 
stereograms were provided by the Institutes 
mentioned above. Photographic scale varied 
between 1:15,000 and 1:20,000. The forest 
vegetation to be found in the areas photo- 
graphed was classified as heterogeneous, 
further as ''disetáneas'', and virgin forest of a 
sub-tropical type. As a result of the great 
variety in the broad-leaved species the major- 
ity could not be identified on the photo- 
graphs. Research to improve interpretation 
had to be abandoned due to lack of special- 
ized technical staff. 
Nevertheless a broader application of aerial 
photography resulted in a break-down of the 
main vegetation types, the location of these 
types and the relation between forested and 
non-forested areas. In the Province of Chaco 
and Formosa particularly this technique 
proved worthwhile as in those regions the 
forest vegetation is distributed over isolated 
areas. À total survey combined with a forest 
inventory of these forests by pure terrestrial 
methods could only be carried out at a much 
greater expenditure in time and money. 
There can therefore be no doubt of the 
practical value of aerial photography in forest 
survey work in a country such as the Argen- 
tine. It also provides a valuable basis for the 
location of the terrestrial sample plots neces- 
sary for the estimation of timber volume. 
However, it should be realized that the forest 
service does not have at its disposal at the 
moment a permanent team of trained photo- 
interpreters who could devote their time ex- 
clusively to the study of the vegetation by 
aerial photography. Under the annual pro- 
gramme, limited 
mapped, but the results justify an expansion 
in the future. 
areas only have been 
BRAZIL 
The forest inventory mission in the Ama- 
zon which started work in 1954 continued the 
reconnaissance surveys on the basis of tri- 
metrogon 1:40,000 aerial photographs taken 
during the war. In 1959 the fifth area, situ- 
Caete and Mara- 
cacume, and a total of 16.7 
million ha was surveyed. As in the past, the 
ated between the rivers 
was finished 
objective of the surveys was to obtain basic 
data on the composition of the forests, to get 
a clear idea on the accessibility of the for- 
usual, planimetric 
were drawn on the 
est areas. As 
1:200,000 
available aerial photographs; 
maps ol 
basis of the 
this was pos- 
sible as the country was flat; field sampling 
was carried out in the dry land forests so far