Stand Age

one of the basic valuational criteria which characterize a stand. Stands are divided into classes according to their age. For coniferous and hardleaved deciduous stands grown from seeds, 20-year age classes have been determined; for undergrowth and softleaved deciduous stands grown from seeds, ten-year age classes; and for species of brushwood, five-year age classes. A stand in which the ages of the trees vary within the limits of a single class is considered to be of the same age, whereas if the ages fall within several classes, the stand is considered to be of different ages. The ages of trees are determined by the number of annual layers (rings), as seen on the stumps of sample trees which have been cut down or on a cylinder of wood which is removed from the trunk of a growing tree by a special borer. Another method of determining the age of trees is by external criteria, such as the color of the needles, the form of the crown, and the color and structure of the bark.