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Silvicultural treatments for immature central hardwood stands include precommercial and commercial thinnings, lateral branch pruning, fertilization, cull tree deadening, and vine removal. The specifics of these treatments are discussed elsewhere in these Notes. This Note discusses some basic concepts in the selection and application of silvicultural treatments for central hardwoods.

Sapling stands are those in which codominant trees average less than 5 inches d.b.h. Silvicultural treatments in sapling stands can be summed up in two words: CROP TREES. Any silvicultural treatment must help crop trees if the investment in sapling stands is going to pay off. Just cutting "bad" or "undesirable" trees does not insure that crop trees will be helped (see Note 6.04 Response of Sapling Stands to Cultural Treatments).

Foresters generally consider central hardwood stands mature when they are 80 to 100 years old or have reached a specified rotation age. However, by the time stands are 50 to 60 years old and in the large pole/small sawtimber size, they have generally slowed in height growth, their annual basal area growth has leveled off, and except for size, they have many of the characteristics of older stands. Although most central hardwoods are long lived and some can be grown on very long rotations, they generally reach economic maturity at the recommended rotation ages in table 1. At these ages...

Forest stands are managed to achieve some combination of desired products or values. These products or values may include income and tangible benefits from timber production or fees for hunting rights and other recreational activities. The values may be intangible, such as the enjoyment of seeing wildlife or flowering plants, or the simple satisfaction of knowing that there is an area undisturbed by human activities.

The central hardwood area is highly regarded both in this country and abroad for the high quality timber grown on both public and private lands. Buyers of standing timber and logs for lumber and veneer often look to this region first to meet their needs for raw materials. And these buyers have traditionally paid a lot more for quality timber than the usual market price for ordinary trees and logs. As worldwide supplies of quality timber continue to shrink, the demand for quality central hardwoods will grow. A strong potential demand coupled with rapidly growing young stands throughout the...

Short-rotation plantations offer several advantages over longer, more traditional rotations. They enhance the natural productivity of better sites and of tree species with rapid juvenile growth. Returns on investment are realized in a shorter period and the risk of loss is reduced compared with long term investments. Production of wood and fiber can be maximized by intensifying cultural treatments near a processing site, lessening transportation costs.

Over the last 20 years computers have become an efficient tool to estimate growth and yield. Computerized yield estimates vary from simple approximation or interpolation of traditional normal yield tables to highly sophisticated programs that simulate the growth and yield of each individual tree.

Although hardwoods comprise the bulk of the volume in the central hardwood forest, pines are locally important in the oak-pine association, pine types, and plantations. The two principal pine species are shortleaf pine and eastern white pine. Shortleaf occurs primarily in the southern parts of the central hardwood forest: white pine is found in the northern and eastern parts of the region.

A mixed stand is defined as one in which no single species comprises more than 80 percent of the stocking. The growth estimation methods described below can be used not only in mixed stands but in almost any stand, regardless of species composition, age structure, or size structure. The methods described are necessary to accommodate the complex species mixtures and irregular size distributions characteristic of many central hardwood stands. These same methods can also be used in pure or even-aged stands, although they will not always be best for those stands.

Growth and yield of plantation grown black walnut depends upon the site productivity and management practices such as vegetation control and thinning. Growth and yield information for all the various combinations of sites and management practices is not available; however, there is some information from unmanaged plantations which provides reasonable estimates. The following graphs relate directly to plantations established with site preparation and weed control the first 2 or 3 years, but no additional management.