the comprehensive inventory of a forest and the compilation of a technical description (valuation survey and map) of stands of timber, and the determination of the stands’ age, the reserves (quantity) of timber, and the growth and volume of individual trees and parts of trees.
Forest valuation concerns itself primarily with large forest tracts, divided into sectors. It makes use of both aerial and ground techniques. In aerial valuation, aerial photography is used; the photographs are subsequently interpreted and employed as sketch maps. Ground valuation is based either on visual estimation or on tree counts and various survey indexes, with the help of any of several instruments or devices. The two methods are usually used in combination. In the valuation of large numbers of trees, the trees are classified in terms of their various parts, which have various uses in the national economy. Special tables help determine the volumes of trees and parts of trees.
In the USSR, forest valuation is carried out at regular intervals as part of forest management, namely, by teams sent out by the Lesproekt All-Union Aerial Photography Forest Management Association. It is also carried out when a site is assigned to cutting, namely, by forestry sections and state forestry establishments. The information gained from forest valuation is the basis on which timber is inventoried, organizational plans are drawn up, and forestry is carried on.
Since whole tree trunks and parts of trees are similar to stereometric bodies, the laws and rules of stereometry are used to determine the volume of felled tree trunks and parts of trees. Forest valuation, a scientific discipline that emerged in the 18th century when forests and forest products became items of commerce, seeks the most accurate methods of measurement. Its objectives include the improvement of measurement techniques and methods; the study and development of methods for the determination of the volume of trees, cut wood, and the reserves of individual stands and forest tracts; and the qualitative and quantitative assessment of trees and whole stands of trees. Further progress in forest valuation involves the replacement of visual estimation by more accurate measures.
Forest valuation has been the basis for many disciplines in forestry. It has increasingly made use of mathematical methods (variational statistics), new weight (volume) tables, and various ancillary standards, such as guides and instruction manuals. Commercial tables have been developed, which are used to establish, by means of average indicators, the output of individual forest products; the methods for determination of the accuracy of forest valuation have been improved. Space photography and combined aerial-ground methods for the study of the earth’s natural resources—including its forests—have opened broad new possibilities for forest valuation.
REFERENCEAnuchin, N. P. Lesnaia taksatsiia, 3rd ed. Moscow, 1971.
N. P. ANUCHIN