عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Renewal volume of felled trees and separation of industrial and cordwood volumes are necessary in order to achieve real harvest rate and royalty interest. Therefore, various methods have been proposed for renewal volume of felled trees, namely traditional or one hundred percent method, regression method, statistical method, and 3p renewal volume method. The present paper aimed at introduction and determination of various methods for renewal volume of felled trees. In one hundred percent method, industrial volume of all trees is measured in a rather accurate manner; also, cordwood volume through an estimative calculation by a renewal volume expert. In regression method, 10% of felled trees are randomly selected and industrial and cordwood volumes are accurately measured; then, the relationship between standing wood volume and industrial and cordwood volumes are estimated and referred to other trees. In statistical method, trees are divided into four groups (i.e. beech, hornbeam, oak, and other species) and a diameter is assigned for each level which is mean industrial wood for each tree. Furthermore, a regression equation is defined for each group. In 3p renewal volume method, field operation is performed through accurate measurement of volume of industrial and cordwood trunks of the sample felled trees following selection of sample trees selected from tagged trees. The derived coefficients are referred to all felled trees. It was concluded that the 3p method owns more advantages than other methods.