Forestry as an Returns from timber raising are realized perhaps once or twice in a lifetime, hardly more often at best. The amount of capital required is large. In the practice of private forestry certain carry ing charges like taxes, interest, and protection costs must be met annually, while the return on the investment must be deferred. There fore, only long-lived agencies, such as the State and corporations and large capitalists, are able to engage in it with any certainty of profit. Furthermore, where capital and interest are mixed together in an investment, as is the case with an investment in forestry, the pressure of competition or the necessity of meeting fixed charges leads very readily to forced exploita tion of the timber — in other words, to the uneconomic anticipation of the harvest. The element of time and the consequent temptation to private owners to turn from scientific man agement to mere exploitation makes it easier for the State than for even large capitalists to practice forestry. When the forests are owned by the public, the infrequent returns are of no disadvantage, while taxes and interest charges do not have to be met; and as a result of the assurance of stable ownership systems of man agement beneficial to the forest but requiring long periods of time may be undertaken with the certainty of success.
Technical In order to utilize the present forest most economically and profit ably and at the same time to provide for a new growth which will produce timber and other forest products in the future, the science of forestry concerns itself with both forest man agement and forest production. Forest pro duction comprises silviculture, forest protec tion, and forest utilization; forest management, the mensuration and valuation of forests, work ing plans, and forest policy.
The practical aims of silviculture are to se cure quick reproduction after the removal of timber, to reproduce valuable species rather than those which are less marketable, to secure a large yield, to produce timber trees of good quality, and to secure the most rapid growth compatible with good stands and good quality. More broadly, silviculture has to do with the improvement of forest stands and with their establishment by natural reproduction or by artificial seeding and planting. Various so- called silvicultural systems which are adapted for use under certain conditions, are made use of for the accomplishment of these aims. These are known as the selection system, clear cutting systems, the shelterwood system, and the coppice system. In practice these are combined and modified in various ways. Forest protec tion is concerned with the protection of the forest against fires, animals, insects and fungi, and all other detrimental influences. In Amer
ica protection against forest fires is the most important, although such pests as various kinds of beetles, white pine blister rust, chestnut blight, and mistletoe are common and have to be fought and guarded against. Forest utiliza tion deals with the best methods of utilizing all classes of forest products. This involves put ting different classes of material to the use for which they are best fitted, determining the proper season for cutting and logging, and the methods of transportation from the forest to the mill and from the mill to market. Utiliza tion takes into account not only the timber but all the by-products, such as pasturage, tanbark, extract wood, firewood, naval stores, etc. For the calculation of the material standing on a given area, the yield to be expected, and the value of single trees or whole stands, methods of forest mensuration are employed based on the determination of the dimensions, age, vol ume, the increment of trees and forests. These also serve as a basis for calculating the effect of different methods of treatment of the forest. Forest valuation aims to determine the value of the growing stock in the forest and the value of the forest soil. It is based, of course, on the knowledge derived from silviculture and men suration; and is usually expressed as expecta tion value (the present value of all returns ex pected less the present value of all expenses which will be necessary to obtain those re turns), cost value, or sale value. These expressions are applied to the forest-soil, the growing stock, and the rental of a forest prop erty. Forest management accomplishes the ob jects of forestry by means of forest working plans, which are based upon all other knowl edge which has been gathered regarding the forest. The character of the working plan de pends upon the object for which the forest is to be managed, so that the working plans for forests with different objects would be entirely different. The working plan takes special cognizance of the fact that for every tree or forest there may be three different kinds of increment; that is, volume, quality, and price increment. It usually includes a detailed de scription of the stand, the topography and cli mate, cost of logging, fire hazard and means of protection, the market for the product, the unit divisions of the forest, known technically as compartments, the length of the rotation, the objects of the silvicultural system, the treatment of the different species, and the general object of the forest management. Detailed description of the means to be used in handling the forest such as maps, organization, etc., are also necessary.