535 
METHODS OF INTERPRETATION OF AERIAL PHOTOGRAPHS 
IN FOREST INVENTORY AND MANAGEMENT IN THE USSR 
V.I. Sukhih, S.G. Sinitsin 
Ministry of Forestry, "Lesprojekt" 
Moscow, USSR 
The forest is the most important component of the biosphere. 
It is extremely significant for the national economy as well as for biological 
and social aspects. 
It is necessary to have data of forest resources for the proper 
operational management of forestry, for the planning of forest yield and for 
forecasting purposes. In the USSR the determination of forest resources and 
condition is the role of Forest Inventory and Management. 
Soviet practising foresters have accomplished much as far as 
forest inventory and forest mapping are concerned. They have estimated the 
whole stock of forest of the country, which occupies an area of over 1200 
millions of hectares. The annual amount of work in forest inventory and 
management at present is 45 millions of hectares and is to be increased up to 
50 millions hectares, thanks to the application of survey and aerial data, 
which are the technical base of modern forest inventory and management. 
The basis of estimation interpretation is the analytical method, 
which is based on the intensive analysis of all the factors affecting 'the 
character of the image of forest cover, as well as upon the knowledge of bio 
logical characteristics of the overhead cover and the structure of the over 
head cover. 
One of the first and important tasks is the division of the 
forest stock into homogeneous forest compartments, the total area of which 
varies from about 0,1 hectares to dozens of hectares. Without the use of 
aerial photographs the severance cutting of sites is needed every 125-500 
meters depending on the category of forest inventory. The use of surveying 
materials permits one to refuse all the severance cutting or reduce its 
extent by three times and in this way, contours of most of estimation forest 
compartments can be determined on the base of aerial photographs interpreted 
in the laboratory and partially in the forest. 
The accuracy of boundaries of forest compartments is of great 
practical and economical importance, especially in the areas of intensive 
forestry, where forest compartments are rather small. For example, when the 
size of the forest compartment is about 1 hectare, a 20-meter error in 
determination of boundaries causes a ± 40 percent error in determination of 
the area. 
Thanks to the difference in color tones of imagery of some types