Nondestructive Sampling Applications of the Tele-Relaskop in Forest Inventory

The Tele-Relaskop dendrometer permits accurate upper stem measurements of diameter and height on standing trees for volume and form computations without destructive sampling. Its 8 x magnification and system of scales and relative measurement units facilitates measurements from any convenient distance. Horizontal and vertical percentages of the horizontal distance from the instrument to the tree axis are converted to defined units of measure during computations. Practical applications of the Tele-Relaskop are in growth and yield studies, CFI measurements, traditional volume equation construction, and inventory computations where numerical evaluation of tree form and/or volume is desired. Applications involving computations beyond stem diameters at calculated heights require a microcomputer and specialized software containing analytical techniques for the numerical description of tree form, one of which is a polynomial taper model. These software systems are available to link Tele-Relaskop procedures to traditional inventory processing. Single-tree taper equations are used to calculate tree volume to user-defined merchantability limits, and the volumes are fitted to a combined variable regression model to produce volume equations for use in inventory computations. Coefficients from the volume equations and multiple-tree, species-average taper equations can be used by inventory processors to compute gross tree volumes. Taper coefficients can also be used to compute scaling diameters of variable log length segments within inventory sample trees. South. J. Appl. For. 21(2):75-83.