Timber may be sold as stumpage (trees before they are cut) or as harvested products (sawlogs, veneer logs, or pulpwood). If trees are sold as harvested products, the sale is customarily based upon measured volume. Trees marketed as stumpage may be sold by boundary, a measured estimate of stand volume, or individual tree measurements.

Standing-tree and log volumes can be measured using a scale stick designed to fit Virginia timber conditions. With it you can measure the diameter of a tree, the number of 16-foot logs or the length of pulpwood in a tree, and the diameter and length of sawlogs. Tables printed on the stick provide for varying board-foot volumes for standing trees and for sawlogs of varying lengths.

Precision Farming. Modern agricultural management practices are changing from assuming homogenous fields to attempting to address field variability by dividing the field into smaller zones and managing these zones separately. Precision farming can be defined as the gathering of information dealing with spatial and temporal variation within a field and then using that information to manage inputs and practices (Precision Farming: A Comprehensive Approach, Virginia Cooperative Extension (VCE) publication 442-500). Precision farming is made possible by linking computers, on-the-go sensors, Global Positioning Systems (GPS), and other devices. This publication discusses GPS principles and the technology that makes it possible.