TABLE 2.-Yield of well-stocked slash-pine stands per acre in the form of crossties, pulpwood, and fuel wood.1

! This is a preliminary table, based on insufficient measurements to make the figures final. The range of figures shows the different yields on different qualities of land.

YIELD OF SAW TIMBER.

The market is taking lumber cut from smaller and smaller sized timber. This is particularly true in the South. Increasing amounts of slash pine for both local use and shipment are being sawed each year from small turpentined trees from 25 to 40 years of age.

Table 3 summarizes the approximate amounts of saw timber per acre, in terms of board feet, that can be cut from slash-pine stands of different ages, growing in well-stocked stands of approximately even-aged trees. For example, a slash-pine stand about 30 years old, of good density, taking all trees measuring 10 inches and over in diameter at breast height, when closely sawed may be expected to yield from 2,300 on poorer land up to 13,600 board feet on better situations. If all trees measuring 8 inches and over in diameter are sawed up, the yield should be somewhere between 5,500 and 16,000 board feet. This represents an average yearly production, considering the 10-inch diameter limit, of about 260 board feet per acre, and 360 board feet for trees 8 inches and over. For the average sizes of the trees and number per acre for the corresponding ages, reference should be made to Table 1.

TABLE 3.-Amount of saw timber in board feet grown in slash-pine stands that are even aged and well stocked with trees.1

1 See attached sheet for footnote.

The yield in lumber when closely and carefully sawed down to a top diameter inside bark of 3.5 inches. By the Doyle rule small logs scale from one-third to one-half less than the amount that can be cut in careful and close sawing.

The future yields of present stands, if left to grow for 5, 10, 15, or more years, can be predicted by referring to the yields for the corresponding ages in Table 3.

This table is for stands having approximately the proper number of trees fairly evenly spaced on the ground. The amount of lumber shown by mill scale is that which can be sawed out by using the trees down to small diameters and utilizing the material in the logs by careful sawing (with an ordinary circular saw) rather than by the old-time rough-and-ready, wasteful methods. The difference between the mill scale and the scale by the Doyle rule is striking. For example, an acre of 25-year-old slash pine well stocked on the ground, if carefully sawed, taking all trees measuring 10 inches and over in diameter (breast high), would yield on medium land up to 10,000 board feet. The very low scale of the Doyle rule, which unfortunately prevails in common use, is shown by the fact that measuring by that rule the logs from all trees in the same stand, 7 inches and over in diameter and on the same grade of location, would scale only up to 4,710 feet.

The following essential facts concerning a few of the stands actually measured will serve as an illustration of what yields may be expected from well-stocked slash-pine stands, such as are locally considered to be "dense" stands.

(1) A 21-year-old stand, consisting of 384 trees per acre, averaging 8 inches in diameter at breastheight and 56 feet in height, contained 45 cords of wood with the bark on, or 34 cords of peeled wood. If all trees measuring 10 inches and over in diameter were cut, the stand would saw out about 6,400 board feet; or if all trees 8 inches and over were taken, it would saw about 10,300 board feet. By the Doyle log rule, however, all trees measuring 7 inches and up in diameter would scale only 3,700 board feet.

(2) A 25-year-old stand, with 274 trees per acre, averaging 63 feet in height and 9 inches in diameter, contained 47 cords of wood with the bark, or 37 cords of peeled wood. The trees 10 inches and over in diameter would saw out, down to small top diameters, about 10,700 board feet per acre; or about 13,500 feet would be obtained if trees 8 inches and up in diameter were taken. If the logs in the trees measuring 7 inches and over in diameter were scaled by the Doyle rule, there would be only 5,800 board feet per acre.

(3) A 26-year-old stand, with 754 trees per acre, would cut 64 cords of wood with the bark, or 47 cords of peeled wood. There would be a total of only 1,300 board feet if trees measuring 10 inches and up were taken, or 8,000 feet from all trees 8 inches and over in diameter. The Doyle rule showed only 1,360 board feet.

(4) A 30-year-old stand, with 114 trees per acre, averaging 11 inches in diameter and 69 feet high, contained 31 cords with the bark, or 25 cords of peeled wood. There would be 9,672 board feet per acre of saw timber in the trees 10 inches and over in diameter, or 10,700 board feet in the trees 8 inches and over in diameter. If scaled by the Doyle rule, the stand had only 5,700 board feet.

(5) A 51-year-old stand, which consisted of 220 trees per acre, averaging 70 feet in height and 9.4 inches in diameter, contained 57 cords of wood with the bark, or 44 cords of peeled wood. The stand would cut out 10,100 board feet from all trees 10 inches and over in diameter, or 14,600 feet from trees measuring 8 inches and over. The Doyle rule gave only 5,900 feet of saw timber.

TURPENTINE AND ROSIN PRODUCTION.

Slash pine produces large quantities of rosin, or gum, of high quality. In this respect it excels all other native pines.

The gum of slash pine, when freshly exuded, is limpid, and about the color of light-yellow honey. As compared with longleaf or "hill" pine, its nearest competitor, it yields a higher percentage of turpentine and a relatively smaller amount of rosin of a higher grade. Beginning to run a little later in the spring than longleaf, probably because of the colder situation in low ground, slash pine keeps up a heavy flow until late in the season, considerably past the time when longleaf becomes dry-faced; furthermore, it does not produce "scrape," as does longleaf. It is not uncommon to hear it said that slash pine is more apt to die from turpentining than its associate, longleaf pine. Observations make it almost certain that the basis for this statement is the almost universal custom of more heavily cupping slash pine because of its very free production of crude gum, with its high content of spirits of turpentine, and the desire to obtain the maximum amount.

It is difficult for private owners and operators to break away from the custom of cupping very small trees and overcupping large ones. In their desire for immediate returns they sacrifice heavily in income, or "kill the goose that lays the golden egg." A case is known where slash-pine trees were cupped at 8 years old and the same trees back-cupped 7 years later. Frequently all trees down to 7 inches in diameter are cupped, two cups hung on trees down to 9 or 10 inches, and three cups hung on trees 13 inches and over by the laborers who are paid on the basis of each 1,000 cups hung, or of each "crop" of 10,000 cups. Very close working is wasteful practice, except for the purpose of clearing up land or thinning heavy stands. (Fig. 12.) With the faces ranging in width from 7 to 11 inches, the bars (portions of bark and wood left between the faces) are reduced to widths from 1 to 3 inches, which are entirely too narrow to permit of the trees functioning properly.

The flow of gum appears to be generally in proportion to the size of the trees and the size of the face, up to the point where the tree is faced too severely. Practical men in the turpentine industry are heard repeatedly expressing the opinion that a large percentage of the smaller-sized trees now bled are too small to pay for the cost of

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operation. The almost complete loss by wind and fire of small trees during or after severe turpentine operations is another potent economic reason for adopting conservative methods. (Fig. 13.)

IMPROVED METHODS OF TURPENTINING.

The ultimate aim in the conservative handling of slash-pine stands is to make them continuously productive and capable of supporting a permanent and self-sustaining industry. The continuous operation of turpentine forests has been practiced for many years in France and is regarded by well-informed persons as possible and practicable in this country.

FIG. 12.-Slash pine in central Georgia ready for thinning by turpentining. The trees are 20 years old, from 5 to 10 inches in diameter and 45 to 55 feet tall. There are 474 trees of the larger sizes an acre and 922 trees an acre of all sizes.

The cupping method, instead of the wasteful boxing of trees, has become generally used by the more progressive operators, but unfortunately it is not yet prevailingly adopted. Light chipping is a step toward improved methods for securing increased yield and lessening destruction of timber. Another step in the right direction for conservative operating consists in restricting the cupping of young trees of sizes below certain minimum diameter limits, and greatly lengthening the period of operation on the individual tree and forest by proper regard for the laws of tree life, including the production of resin by the tree. A successful farmer in south Georgia, in a recent lease of turpentine rights on his timber, made the following restrictions which are probably typical of what the more conservative owners regard as the best practice with their timber:

No tree shall be bled measuring below 10 inches at 2 feet from the ground; 1 cup to be allowed on trees from 10 to 14 inches, inclusive; and 2 cups on trees 15 inches and over in diameter.

A summary of practices that are more generally recognized to be advisable as a means of getting the most revenue out of their timber, consistent with conditions of labor and market, includes the following:

(1) The cup-and-gutter system should be exclusively used. The advantages of the cup-and-gutter system over that of boxing are that (a) the yield of turpentine is considerably greater and the quality of the rosin better; (b) the loss and damage from fire is greatly lessened through the elimination of the deep cut (box) into the tree;

FIG. 13.-Early loss of small slash pine timber from deep chipping. If cupped only on one side these small trees are nearly half way cut through, making them easy prey for wind of only moderate force.

and (c) less injury being done to the tree, it is enabled to maintain its vigor and is less liable to be wind-thrown. One count, following a windstorm on two adjacent tracts, showed that 13 boxed trees were blown down to 4 cupped trees; also that 37 of the boxed trees died to only 17 of the cupped trees.

(2) No trees under 10 inches in diameter (breast high) should be tapped.

(3) Two faces should be allowed on trees measuring 14 inches and over in diameter at breast-height.

(4) Not more than two faces should be allowed on any tree.

(5) The faces on trees 12 to 15 inches in diameter should not exceed 12 inches in width; and those on trees above 16 inches in diameter should not exceed 14 inches in width.