Trees that are too small or too poor in quality to be sold for sawlogs are often sold for pulpwood. Ultimately, these trees are chipped or ground up to manufacture products such as paper, hardboard, and various types of structural board.
Minimum DBH for pulpwood trees is 5 inches. Minimum DIB is the larger of either 4 inches or 50 percent of tree DBH. (The minimum DIB for a pulpwood tree with a DBH of 12 inches, therefore, is 6 inches.) In the Lake States pulpwood commonly is cut to 100-inch lengths.
The basic unit for estimating pulpwood volume in trees is the cord. A standard cord is a closely stacked pile of logs containing 128 cubic feet of wood, bark, and air spaces between logs. A cord frequently is described as a stack of wood 8 feet long, 4 feet high, and 4 feet wide (Figure 2-5). The solid wood content (excluding bark and air space) of a cord varies from about 65 to 95 cubic feet depending on the diameter, roughness, and crookedness of the pieces. An accepted average value in the Lake States is 79 cubic feet of wood per cord.
Pulpwood also can be purchased by the ton. Different tree species have different wood densities. A 12-inch diameter red oak log will weigh much more than a 12-inch diameter aspen log because the oak log is much denser. For example, one cord of aspen weighs 2.4 tons, while one cord of red oak weighs 2.85 tons. Weight also varies depending on the season of the year because of the changing moisture content of logs.