| УДК |
Аннотация: The subject is introduced with a reference to the employment of forest inventories in Canadafor the collection of important data on the forest resources, including information for use in forest management. It is stated that from an operational point of view the most important development in forest inventories in Canada during recent years has been the Federal-Provincial Forestry Agreements entered into initially in 1951. The special value of aerial photography, and advances made in its use in forestry, are emphasized. An indication of the dependence of forest inventories on surveying and mapping and of the construction and use of forest maps is provided. Photointerpretation for forestry purposes, including the determination of tree heights and the density of the forest stand, and recognition of tree species, is mentioned. In this connection the possibilities for special aerial photography are recognized. The approach to forest inventories through stratification and sampling is referred to, as are various sampling methods. Also stand volume tables and tree volume tables, based on variables ascertainable from the aerial photographs, are mentioned. Reference is made to current investigations in the use of large-scale aerial photographs for sampling purposes.
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