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imately 61,400 km 2 . The first aim was to arrive at a broad classification of the forest with 
a minimum of field work in order to guide the forest inventory in a proper way. Five 
general types could be distinguished and their distribution was indicated on working maps 
in scale 1 : 50,000. In flat terrain these maps were made by slotted templet compilation 
and by way of a sketchmaster. The Zeiss Stereotope was used in mountainous terrain, 
where uncontrolled formline maps (interval 100 m) were prepared. A forest quality map 
in scale 1 : 100,000 was subsequently compiled from the information obtained. 
Forest sampling in flat and low hilly areas was carried out as a strip survey, whereas 
sample plots were selected if mountainous conifer stands were concerned. Finally, forest 
type maps in scale 1 : 20,000 were made of the parts considered for timber felling or road 
building in the near future. This aerial photographic approach proved its utility in the 
circumstances prevailing in the island. 
Although Surinam is an autonomous part of the Kingdom of the Netherlands, we 
include its work related to natural resources inventory in this report. 
The country is now completely covered by aerial photographs in scale 1 : 20,000 (north 
ern areas) and 1 : 40,000. The photos serve for the compilation of base maps in scale 
1 : 40,000 and 1 : 100,000 and they are furthermore used for interpretation purposes by 
soil experts, foresters and geologists. 
The photo-geological approach, prior to the field work, is common practice with the Geo- 
logisch-Mijnbouwkundige Dienst. One of its staff members, O’Herne, is specialized in the 
subject. A considerable amount of rapid scanning has been carried out in the beginning in 
relation to the proper planning of the airborne magnetometer survey carried out by the 
Canadian Aerial Survey Corp. Presently the result of this magnetometer survey is combined 
with photogeological and field evidence for obtaining the best results in the geological 
survey and the mineral exploration of the country. 
The use of aerial photographs in soil survey initiated by Van der Eyk and Van der Voorde 
is now common practice and is carried out by all soil surveyors working in this country. 
The Forestry Service is primarily interested in vegetation mapping for the selection of the 
areas most suitable for forest exploitation. Detailed ground surveys of these areas are sub 
sequently carried out. Detailed mapping from the air of Babun trees in the swamps proved 
possible from the 1 : 10,000 scale photographs. This was particularly important because of 
the difficulties associated with field work in these swamps. The field check is usually carried 
out as a strip survey. 264,000 ha have been explored in this way in ten years’ time.