Wood and Forest Part 43

In order to obtain this result, certain forest conditions have to be preserved. What these conditions are, we have already noticed (see Chap. V, The Forest Organism). They are partly topographical and climatic and partly historical. They include such factors as, soil, moisture, temperature, and light, the forest cover, the forest floor, the density and mixture of growth, all conditions of forest growth.

It is only as the forester preserves these conditions, or to put it otherwise, it is only as he obeys the laws of the forest organism that he can preserve the forest. For a long period of our national history, we Americans were compelled to conform our life and inst.i.tutions to the presence of the primeval forest, but by long observation of what happens naturally in the forest, there have been developed in Europe and in America certain ways of handling it so as to make it our servant and not our master.

These ways are called silvicultural systems. They are all based on the nature of the forest itself, and they succeed only because they are modifications of what takes place naturally in the woods.

As we have seen above (p. 220) trees reproduce themselves either by sprouts or by seeds. This fact gives rise to two general methods of reproduction, called the coppice systems and the seed systems.

[Ill.u.s.tration: Fig. 123. Chestnut Coppice. _U. S. Forest Service._]

_Coppice_, Fig. 123. In the simpler form of this system, the forest is divided into a certain number of parts, say thirty, and one part is cut down each year. New sprouts at once start up, which will mature a year later than those in the part cut the previous year. Where the trees of each part are thirty years old at cutting, thirty years is called the "rotation period." The coppice is said to be managed on a thirty-year rotation. The system is widely used in eastern United States, for fuel, posts, charcoal, railway ties, and other small stuff, as well as for tan-bark. This system is modified by maintaining an overwood composed of seedling trees or selected sprouts above a stand of sprouts. This is called the Reserve Sprout method and is used with admirable results by the French.

_Seed Forests._ In contrast with coppice forests, those raised from seeds produce the best cla.s.s of timber, such as is used for saw logs.

[Ill.u.s.tration: Fig. 124. Seeding from the Side. White Pine. New Hamps.h.i.+re. _U. S. Forest Service._]

_Seeding from the side_, Fig. 124. Many forests naturally spread at their borders from the scattering of their seeds. "Old field pine" is so called from its tendency to spread in this way on old fields. This natural "Seeding from the Side" has given rise to the "Group System,"

in which an area of ripe trees is cut off and the trees alongside are depended upon to reproduce new ones on the cut-over area. The openings are gradually enlarged until all the old timber is cut out, and the young growth has taken its place. In its best form there is a definite "rotation period," say eighty years. This system is simple, safe, and very useful, especially for small openings in woodlots. A modification of this is the "Strip System," in which long narrow openings, say seventy-five yards wide, are cut out and gradually widened. The strips are cut in the proper direction so that the prevailing winds will cross them, both for the sake of avoiding windfalls and to help scatter the seed. Where the soil is very dry, the strips may run east and west to protect the seedlings from the sun.

[Ill.u.s.tration: Fig. 125. Virgin Forest, Trees of All Ages. Jackson Co., North Carolina. _U.S. Forest Service._]

_Selection Forests._ The typical virgin forest, Fig. 125, is one in which trees of all ages are closely intermingled, and it may be either "mixed" or "pure." If a farmer had a woodlot of this character and every year went over it with the ax, cutting out such trees as he needed for his purpose, and also trees whose removal would improve the woods, but taking care not to cut out each year more than the amount of the average growth, he would be using the "Selection System." This system is the best way of keeping a forest dense and of preserving one which is difficult to start afresh, as on a mountain slope; it is practicable where the woods are small or under a high state of care, as in Europe, where this system has been in use for seven centuries.

But the cost of road maintenance and of logging is high and it is therefore impracticable in most lumber regions in the United States, except for woods of especial value, like black walnut.

_Localized Selection._ If instead of the whole forest being treated in this way every year, it were divided up into perhaps twenty parts, and from each part there were taken out each year as much lumber as would equal the annual growth of the whole forest, such a system would be called "Localized Selection." The cost of logging would be greatly reduced and if care were taken to leave standing some seed trees and to cut no trees below a determined size, as twelve inches, the forest would maintain itself in good condition. This system has been applied with great success in certain private forests in the Adirondacks.

_Regular Seed Forest or High Forest._ In the system already mentioned above of seeding from the side, the trees near the cut areas are depended upon to seed these areas. Moreover, no especial pains are taken to preserve the forest floor and the forest cover. But all trees do not bear seeds annually, nor do their seedlings thrive under such conditions. In other words, in some forests especial pains must be taken to secure reproduction, and the forest conditions must be maintained with special reference to the growing crop. For this purpose, the cuttings take place thru a series of years, sometimes lasting even twenty years. These reproduction cuttings have reference, now to a stimulus to the seed trees, now to the preparation of the seed bed, now to the encouragement of the seedlings. Then later, the old crop is gradually cut away. Later still, in twenty or thirty years, the new forest is thinned, and when it reaches maturity, perhaps in one hundred or two hundred years, the process is repeated.

This is called the "Regular Seed Forest." It produces very valuable timber, and has been used for a long time in Switzerland, especially for beech and balsam.

The system is complicated and therefore unsafe in ignorant hands, and the logging is expensive.

_Two-storied Seed Forest._ A modification of the system of Regular Seed Forest is the planting of another and a tolerant species of tree under older intolerant trees to make a cover for the soil, to prevent the growth of gra.s.s and weeds, and to improve the quality of the upper growth.[2]

An ill.u.s.tration of a natural two-storied seed forest is shown in Fig.

126.

[Ill.u.s.tration: No. 126. Two-storied Seed Forest. Fir under Beech, Germany. _U. S. Forest Service._]

_Planting._ The planting of forest trees is a comparatively unimportant part of modern forestry. It is a mistaken idea, not uncommon, that the usual way of reproducing forests is to plant trees.

It is true that in the pineries of North Germany and in the spruce forests of Saxony, it is common to cut clean and then replant, but it is absurd to conclude, as some have done, that forestry consists of planting a tree every time one is cut. Even if planting were the best method, many more than one tree would have to be planted for each one cut, in order to maintain the forest. So far as America is concerned, not for a long time will planting be much used for reproduction.

The greater portion of American woodlands is in the condition of culled forests, that is, forests from which the merchantable trees have been cut, leaving the younger individuals, as well as all trees belonging to unmarketable species. Even on the areas where the lumbermen have made a clean cut of the original timber, new trees will come up of themselves from seeds blown from the surrounding forests or falling from occasional individuals left standing. (Bruncken, p. 133.)

The usefulness of planting in America is mainly for reclaiming treeless regions, as in the west, and where timber is high priced.

The area of planted timber in the Middle West aggregates many hundred thousand acres, once waste land, now converted into useful woods.[3]

Planting has been made possible in the far west by extensive irrigation systems, and farther east by the lessening of prairie fires, which once set the limit to tree growth in the prairie states.

In many parts of Illinois, southern Wisconsin and other prairie States, there is much more forest land than there was twenty-five years ago.

What planting can do, may be seen on some worn out pastures in New England, Fig. 127. With the western movement of agriculture, the abandoned farms of New England are to some extent becoming re-forested, both naturally and by planting, as with white pine, which grows even on sandy soil. Between 1820 and 1880, there was a period of enthusiastic white-pine planting in New England, and tho the interest died on account of the cheap transportation of western lumber, those early plantations prove that white pine can be planted at a profit even on sand barrens. Once worn out and useless pastures are now worth $150 an acre and produce yearly a net income of $3 or more an acre.

[Ill.u.s.tration: Fig. 127. Planted White Pine, Fifty Years Old, Bridgewater, Ma.s.s. _U. S. Forest Service._]

IMPROVEMENT.

Besides utilization and preservation, the third main object of forestry is the improvement of the forest. It is not an uncommon mistake to suppose that the virgin forest is the best forest for human purposes. It is a comparatively new idea, especially in America, that a forest can be improved; that is, that better trees can be raised than those which grow naturally. Lumbermen commonly say, "You never can raise a second growth of white pine as good as the first growth."

As if this "first growth" were not itself the successsor of thousands of other generations! There is even a legend that white pine will not grow in its old habitat. Says Bruncken,

Many people probably imagine that a primeval wood, "by nature's own hand planted," cannot be surpa.s.sed in the number and size of its trees, and consequently in the amount of wood to be derived from it. But the very opposite is true. No wild forest can ever equal a cultivated one in productiveness. To hope that it will, is very much as if a farmer were to expect a full harvest from the grain that may spring up spontaneously in his fields without his sowing. A tract of wild forest in the first place does not contain so many trees as might grow thereon, but only so many as may have survived the struggle for life with their own and other species of plants occupying the locality. Many of the trees so surviving never attain their best development, being suppressed, overshadowed, and hindered by stronger neighbors. Finally much of the s.p.a.ce that might be occupied by valuable timber may be given up to trees having little or no market value. The rule is universal that the amount and value of material that can be taken from an area of wild forest remains far behind what the same land may bear if properly treated by the forester. It is certain, therefore, that in the future, when most American forests shall be in a high state of cultivation, the annual output of forests will, from a much restricted area, exceed everything known at the present day. (Bruncken, _North American Forests and Forestry_, pp. 134-135.)

It is probable that the virgin forest produces but a t.i.the of the useful material which it is capable of producing. (Fernow, p. 98.)

Mr. Burbank has demonstrated that trees can be bred for any particular quality,--for largeness, strength, shape, amount of pitch, tannin, sugar and the like, and for rapidity of growth; in fact that any desirable attribute of a tree may be developed simply by breeding and selecting. He has created walnut trees, by crossing common varieties, that have grown six times as much in thirteen years as their ancestors did in twenty-eight years, preserving at the same time, the strength, hardness and texture of their forebears. The grain of the wood has been made more beautiful at the same time. The trees are fine for fuel and splendidly adapted to furniture manufacture.

(Harwood, _The New Earth_, p. 179.)

Nature provides in the forest merely those varieties that will survive. Man, by interfering in Nature's processes but obeying her laws, raises what he wants. Nature says: those trees that survive are fit and does not care whether the trees be straight or crooked, branched or clear. Man says: those trees shall survive which are fit for human uses. Man raises better grains and fruits and vegetables than Nature, unaided, can, and, in Europe, better trees for lumber. In America there has been such an abundance of trees good enough for our purposes that we have simply gone out and gathered them, just as a savage goes out to gather berries and nuts. Some day our descendants will smile at our treatment of forests much as we smile at root-digging savages, unless, indeed, we so far destroy the forests that they will be more angered than amused. In Europe and j.a.pan, the original supply of trees having been exhausted, forests have been cultivated for centuries with the purpose of raising crops larger in quant.i.ty and better in quality.

There are various methods used in forest improvement. Improvement cuttings, as the name implies, are cuttings made to improve the quality of the forest, whether by thinning out poor species of trees, unsound trees, trees crowding more valuable ones, or trees called "wolves"; that is, trees unduly overshadowing others. Improvement cuttings are often necessary as a preliminary step before any silvicultural system can be applied. Indeed, many of the silvicultural systems involve steady improvement of the forest.

The pruning of branches is a method of improvement, carrying on the natural method by which trees in a forest clean themselves of their branches.

Seeds of valuable species are often sowed, when the conditions are proper, in order to introduce a valuable species, just as brooks and ponds are stocked with fine fish. In general it may be said that improvement methods are only in their infancy, especially in America.

[Footnote 1: A concise and interesting statement of the relation of the forest to rain and floods is to be found in Pinchot: _Primer of Forestry_, Bulletin No. 24, Part II, Chap.

III.]

[Footnote 2: For an interesting account of an application of this method, see Ward, p. 35.]

[Footnote 3: To encourage such forest extension, the Forest Service is doing much by the publication of bulletins recommending methods and trees suited to special regions, as, e.g., on Forest Planting in Illinois, in the Sand Hill Region of Nebraska, on Coal Lands in Western Pennsylvania, in Western Kansas, in Oklahoma and adjacent regions, etc.]

THE USE OF THE FOREST.

REFERENCES:[A]

I Utilization.

Pinchot, _Primer_, II, pp. 14-18, 38-48.

Bruncken, pp. 121-131, _For. Bull._ No. 61.

(1) Protective.

Pinchot, _Primer_, II, pp. 66-73.

Craft, _Agric. Yr. Bk._, 1905, pp. 636-641, (Map. p. 639.) Toumey, _Agric. Yr. Bk._, 1903, p. 279.

Bruncken, pp. 166-173.

_For. and Irrig._, pa.s.sim.

Shaler, I, pp. 485-489.