Practical Forestry in the Pacific Northwest Part 6

SEED SUPPLY

It has been shown in a previous chapter that the owner of deforested land who desires to secure a second crop may find it necessary or cheaper to adopt artificial measures wholly or in part instead of depending upon natural reproduction. These measures may be of two kinds--direct seeding, in which the seed is sown where the trees are to stand permanently, and the planting of trees grown in nurseries.

Whether artificial reforestation is accomplished by means of sowing seed or planting trees, the first requisite is a supply of tree seed of the desired species and of good quality. Unfortunately for the timber owner who wishes to enter upon extensive seeding operations, the business of collecting and preparing forest tree seed for market has received but little attention from old-established seed firms, and it is not always possible to purchase the species and quant.i.ty desired. Moreover, the prices charged are often excessive.

In the Pacific Northwest, however, the demand for seed of Douglas fir and Sitka spruce has led to the establishment of a considerable trade in these species, and at reasonable prices, so that where these species are to be used, or only small quant.i.ties of other species, the timber owner will probably find it to his advantage to purchase the seed rather than to attempt collecting it himself.

Douglas fir seed is quoted at $1.40 to $2.00 per pound and Sitka spruce seed at $2.25 to $3.00.

In purchasing seed it is common practice to specify that it shall be of the new crop, because tree seed kept in ordinary storage loses its vitality materially. When properly stored in air-tight receptacles, however, as is now done by some seed dealers, it will retain its germinative power for several years with only slight depreciation. Moreover, fresh seed, if improperly treated, may be of very poor quality, so that the age of the seed is of little value in the determination of its worth and the only sure method of ascertaining this is by means of germination or cutting tests.

The latter method is the quickest and most simple and consists of cutting open a number of the seeds and ascertaining the per cent whose kernel is sound, plump and moist. Seed of good average quality should contain not more than 25-30 per cent of infertile seed.

When seed cannot be purchased, it is necessary to collect. Since no species of coniferous trees bear abundant crops of seed each year and often several seasons will elapse between good crops, it is necessary to gather sufficient seed when the supply is abundant to provide for succeeding years when the crop is apt to be a failure.

The seed ripens in the fall, usually during August or September, and the cones should be collected at that time. Pines require two years in which to mature the seed; that is, the cones are not fully formed and the seed ripe until the second fall after the fertilization of the flowers in the spring. Most of the other important conifers ripen their seed in the fall of the same season. Shortly after the seed is ripe, the cones open and allow it to disseminate, consequently they must be gathered before this occurs.

The cones are gathered either by climbing the trees and cutting them off from the branches, by picking from the tops of felled trees, or by robbing squirrels' h.o.a.rds. Where squirrels are abundant in the forest, the last method is the cheapest. Climbing trees is practiced only where the trees are small. When this method is employed, the workmen should be equipped with linemen's belts and climbers. Picking from felled trees is readily carried on except where dense underbrush interferes, as is the case in the ordinary Douglas fir forest.

Trees growing in the open, with large crowns extending down the greater part of the bole, bear cones more abundantly than trees in dense forests, and for this reason collecting from scattered open growths can be done more cheaply than on logging areas. Often large quant.i.ties of cones can be purchased from settlers who will collect and deliver them at central points at a stipulated price.

When this method is employed, however, frequent examination of the cones should be made to ascertain that they contain the full number of seed, for often opened cones from which a part or all of the seed has been disseminated will be offered for sale. Insect larvae also often destroy a large proportion of the seed, particularly when the crop is light and care should be taken that the cones purchased are not infested. The prices paid for cones vary from 25 cents to 50 cents per sack for the larger cones, like yellow and white pine, and 50 cents to $1.00 for Douglas fir and spruce, depending upon the abundance of the crop.

After the cones are gathered the seed must be extracted and cleaned.

Where climatic conditions in the fall of the year will permit air-drying, the cones may be spread out on sheets or blankets where they will be exposed to the sun and wind. Under this treatment they will open in from 3 to 6 days, depending upon the weather and the species. Where bad weather will interfere with air-drying, the cones must be dried undercover by artificial heat. This is the method usually employed by professional seed collectors, and where large quant.i.ties of cones are to be treated each year special dry houses are constructed and fitted with elaborate drying apparatus.

The work can be done most cheaply with such an establishment, but for the ordinary timber owner who expects to collect seed only occasionally, a makes.h.i.+ft dry-house which will answer the purpose can be fitted up inexpensively in any unused building. The essential features are shelves or trays 4 feet wide arranged around the walls of the room, one above the other and separated about 8 inches apart, and a heating stove placed in the center of the room. The shelves may be made of burlap stretched tight, or, better still, of wire screening of 1-1/2 inch or 3/4-inch mesh.

After being subjected to a temperature not exceeding 110 Fahr.

for from 24 to 48 hours, the cones will open, allowing the seed to fall out when shaken or pounded. The seed when separated from the cones is then mixed with a coa.r.s.e gravel in about the proportion of 4 to 1 and churned to remove the wings. Finally, all foreign matter is removed by screening and hollow seed blown out by pa.s.sing it through an ordinary fanning mill.

SEEDING VERSUS PLANTING

The selection of the method of reforestation to employ, whether direct seeding or planting, depends primarily upon the character of the area to be restocked. Direct seeding is usually considerably cheaper when the results are satisfactory, but only on the more favorable sites where moisture and soil conditions are right is there any a.s.surance of success. Even in such cases partial or total destruction of the seed often results from birds and rodents. In exposed situations where the soil is shallow, or where because of climatic conditions soil dries out several inches deep during the growing season, the seed may not germinate at all, or the young seedlings may be killed before they have time to send their roots down to the permanent moisture level. In such situations, planting is the only reliable method. If the plant material is of the proper kind and the work well done, satisfactory results are almost certain to follow. Direct seeding is a much more rapid method than planting, and where extensive areas are to be restocked within a short period and seed is abundant, the work can be completed quickly. On the other hand, this method is wasteful of seed because a large proportion fails to germinate and the young seedlings often succ.u.mb to adverse conditions, so that where seed is scarce or its cost high, planting is the more practical method.

Because planting is the most reliable method it has been the one most largely employed in extensive operations, both here and in most European counties, but thorough tests are now being made of direct seeding and under proper conditions it promises to be fairly satisfactory. The Douglas fir region west of the Cascade Mountains offers the most favorable conditions for direct seeding and except on badly exposed south slopes, or where the growth of brush is exceedingly dense, it is believed this method will prove a satisfactory one for the timber owner to employ.

In the yellow pine regions conditions are not so satisfactory for direct seeding, since this tree occurs largely in a region of deficient rainfall. However, natural reproduction is abundant throughout many portions of this type, and it is probable that direct seeding will prove fairly successful if the proper methods are employed and if forest conditions have not been too greatly disturbed. That some method of successfully employing direct seeding with yellow pine be found is greatly to be desired, since yellow pine seedlings do not withstand transplanting well, but there is need for careful experimentation before extensive seeding operations in this type by private timber owners would be justifiable.

Western white pine, it is believed, will be easy to reproduce in most of its native situations by direct seeding, though the greater scarcity of its seed and the fact that it will be more subject to destruction by birds and rodents because of its larger size may make planting the more practical method.

Trees for planting can either be purchased from commercial nurserymen or grown in nurseries established for that purpose near the planting site. When only a few thousand trees are needed it is cheaper to purchase them, but when extensive operations are contemplated, covering hundreds of acres in which millions of trees will be needed, it is far preferable for the owner to grow the trees in his own nursery. Some initial outlay for the establishment of the nursery will be necessary and a practical nurseryman should be employed, but the saving in the cost of the trees will fully compensate for these.

One, two and three year old trees, the latter once transplanted, are usually employed in planting, the older trees being used for the less favorable sites. In planting they are placed in rows equidistant apart, the s.p.a.cing varying from 4 to 12 feet, with a general average of about 6 feet. The work may be done either in the fall after growth has ceased or in the spring before growth commences.

The cost of planting, of course, will vary greatly with the age of the trees, the number planted per acre and the accessibility and character of the planting site. With young trees and wide s.p.a.cing, the cost may be as low as $6.00 per acre, while in more unfavorable situations where older plants are used and planting is more laborious it may be as high as $16.00. A fair average, however, for those areas which a timber owner would be most likely to plant up is about $8.00 to $10.00 per acre.

In direct seeding, several different methods may be employed, such as broadcasting over the entire area with or without previous preparation of the soil, sowing in strips, or sowing in seed spots; but observation and experiment have shown that it is necessary for seed such as Douglas fir, yellow pine and western white pine to come in close contact with the mineral soil in order that it may germinate and the seedlings live; consequently only those methods should be used which will accomplish this. Where the area has been burned over previous to sowing and the mineral soil laid bare, broadcast seeding may be employed. Where the ground will permit the use of a harrow good results are obtainable by scarifying the soil in strips about 10 feet apart and sowing the seed in these strips. On unburned areas covered with a dense growth of fern, salal, moss, gra.s.s, or other plants, this covering must be removed by the seed spot method. This consists in removing the ground cover with a grub hoe or mattock in spots of varying diameter (6 inches to 3 feet) and of various distances apart (6 to 15 feet), and sowing the seed in these spots. The advantages of this method are that a minimum amount of seed is used; the ground can be prepared and the seed covered to whatever extent is desirable, and the soil pressed down. This method is believed to be the one best suited to the greatest variety of sites.

The amount of seed used per acre will, of course, vary with the species and the method used, and the quality of the seed. The following table indicates the approximate quant.i.ty of seed of good average quality required per acre for three different methods, the average cost when collected in fairly large quant.i.ties, and the number of seed per pound:

No. pounds required per acre.

No. seed Cost per Broadcast, Seedspots Species. per lb. pound. entire area. Strips. 6' apart.

Douglas fir 42,000 $1.50 2 - 3 1/2 - 1 1/2 - 3/4 Yellow pine 8,000 .50 10 - 12 2 - 2-1/2 1-1/2 - 2 Western white pine 14,000 .75 6 - 8 1-1/2 - 1-3/4 1 - 1-1/2

The total cost, too, will vary widely, not only because of the different quant.i.ties of seed used but also because of the great extent to which the methods are varied to suit the conditions occurring upon the area. Simple broadcasting without any preparation or treatment of the soil will not exceed 20 cents to 25 cents per acre for labor; harrowing and sowing in strips, 85 cents to $1.10 per acre, and sowing in seedspots, $2.00 to $5.00 per acre. Upon this basis the total cost per acre will approximate the figures given in the table below:

Broadcast over Seedspots, Species. entire area. Strips. 6' apart.

Douglas fir $3.20-4.75 $1.00-2.60 $2.75-6.00 Yellow pine 5.20-6.25 1.85-2.35 2.75-6.00 Western white pine 4.70-6.25 2.00-2.40 2.75-6.00

RATE OF GROWTH AND PROBABLE RETURNS

Of all factors in calculating the financial possibilities of second forest crops, the growth to be expected is the easiest to determine with fair accuracy. Future stumpage value, tax burden and fire risk are all subject to uncertain influences, but the approximate yield of a given species under given natural conditions will be the same in the future that it is now. To predict it requires only study of existing stands without being misled by the influence of conditions which will not be repeated.

On the other hand, an immense amount of misinformation is circulated because of superficial observation. Enthusiasts discovering individual trees which have made prodigious growth, or even fairly extensive stands on fertile soil with heavy rainfall, will compute sawlog yields at 40 or 50 years which are much too optimistic for general application. Others, remembering some stand they have seen in unfavorable localities, or noting shade-suppressed trees which will not be paralleled after the virgin forest is removed, are unduly discouraged. It is most essential that yield tables be made by trained observers who know how to reach the true average, and that the figures either actually come from the region to which they are to be applied or are accompanied by a systematic a.n.a.lysis of climatic and other conditions which permits intelligent comparison.

In calculating another yield on cut-over land, the system for an even-aged new growth, such as will follow clean cutting of Douglas fir, for example, is quite different from that necessary if the cutting amounts only to selection of the merchantable trees and leaves a fair stand of smaller ones. In the latter case, yield tables based on average acreage production are of little use because so much depends upon the character of the stand which remains on the tract in question. Here the basis must be the rate of growth of the average individual tree. An estimate by the number in each present diameter cla.s.s may be made of the trees which will escape logging, showing, let us say for example, about five trees of each diameter from 6 to 12 inches, or thirty-five in all which are over 6 inches. If the growth study indicates that in 20 years there will have been added 6 inches in diameter we can estimate a crop of five trees each of cla.s.ses extending from 12 to 18 inches. Actually the process will not be so simple, for the different aged trees will not grow with equal rapidity, and several other factors must be reckoned with, but the general principle is to apply rate of growth knowledge to the material on hand, and study of this material is essential.

For predicting even-aged crops resulting from entire restocking, the acquisition of necessary basic information is as difficult, or more so, but its application is far simpler. That the ground will be fully stocked by natural or artificial means must be a.s.sumed, but we can also a.s.sume that the result will be influenced only by normal locality conditions and not by accidental condition of the present forest. Therefore we use a yield table and not a growth table. This can be made by actual measurement of existing second growth stands of different ages, which proves not only the growth rate but also the number of trees which the natural shade-thinning process results in at different periods of the forest life. The chief danger of inaccuracy in such information lies in basing it on insufficient measurements or in applying it where soil or moisture conditions are greatly different. The latter error can be guarded against, however, by use of growth figures taken in conjunction with it. For example, if a yield table showing 25,000 feet to the acre at 50 years from seed is accompanied by one showing that the average stand it represents is 125 high at 50 years and its average 50-year-tree is 14 inches in diameter, little investigation is necessary to determine whether in any given locality the growth falls far above or below that.

An attempt to reproduce here any considerable number of growth and yield tables would be of doubtful use without more s.p.a.ce than is allowed to explain how they are made and used. There are many technicalities, both mathematical and silvicultural, and unfortunately most of the available figures for the Northwest, obtained by the Forest Service, have not been generalized enough for wide popular value. This is particularly true of yield tables which necessarily require a.s.suming standards of merchantability. While the best western white pine table a.s.sumes that by the time a new crop is cut 7-inch white pine will be salable, the best fir table was worked upon a 12-inch diameter basis. Obviously this would show an unfairly greater yield of a pine forest containing trees between 7 and 12 inches and be very misleading in calculating financial results at the same age and stumpage rates; yet without the original data there is no way of reducing both tables to the same basis. As an example, however, to indicate how the financial possibilities of second growth can be arrived at if a systematic study is made, let us take the Douglas fir figures referred to.

DOUGLAS FIR

These are exceedingly reliable. Measurements were taken by the Forest Service of practically pure fir on about 400 areas in thirty-five different age stands from 10 to 140 years old, ranging along the western Cascade foothills from the Canadian line to central Oregon.

Since reforestation investment is likely to be confined mainly to the more promising opportunities, only such growth was measured as gave an average representation of the better cla.s.s of the two should all the general territory covered be graded in two quality cla.s.ses of all around ability to produce forests. On the other hand, care was taken not to represent the maximum of the better cla.s.s, data being taken only from permanent forest land and not from rich potential agricultural land which might show unfairly rapid forest growth. The average areas were actually measured and the number, age, form, diameter growth, height growth, board foot contents, etc., of all the trees on them were accurately determined.

Trees 12 inches in diameter 4-1/2 feet from the ground were considered merchantable, and it was a.s.sumed they could be used to 8 inches in the top. From this data were prepared tables and diagrams showing the average development of trees and stands under fairly favorable conditions in the region west of the Cascades.

This gave the following yield per acre:

Age of Stand. Feet, B. M. Age of Stand. Feet, B. M.

40 12,400 90 70,200 50 28,000 100 79,800 60 41,000 110 90,300 70 51,700 120 101,500 80 61,100 130 113,000

Let us see how these figures can be used in answering the primary question of the prospective timber-grower: "Will it pay to hold my cut-over land for a second crop?"

Obviously no certain answer can be printed here, not only because no uniform stumpage prices or carrying charges can be predicted but also because individuals may differ as to what profit is necessary to make the investment "pay," so it will be necessary to a.n.a.lyze the situation so each may select the premises which suit his own case and judgment. The investment made by the holder of cut-over land is of two kinds; that represented by the land which otherwise he might sell, putting the proceeds at work in some other business, and the annual carrying charges which otherwise he might also invest differently. The sum obtainable by investing the money available by sale after logging, adding to it yearly the sum required for fire prevention and taxes, and compounding both at a satisfactory interest for the entire period, is practically the cost of holding the tract for any given number of years. By calculating this cost upon a basis of one acre, and dividing it by the yield board measure which the same period will produce, the cost per thousand feet of growing a second crop is arrived at.

Against this may be set the gross return from the same expected yield at any given stumpage rate. The yield at the end of a 50-year investment will not be that of a 50-year forest, however, for although the carrying cost begins at once, the new forest requires a few years to become established. No exact figure can be set for this, for some seed will sprout the first year and some blank s.p.a.ces may persist several years, but in the tables to follow five years has been allowed for an average. Consequently, instead of calculating on a 28 M yield as the return at the end of 50 years, as indicated in the yield table on the preceding page, the 45-year yield of 20-1/2 M is used, and similarly for the other periods of 60, 70 and 80 years. These four rotations only will be considered here, for in less than 50 years second growth will probably be too small to be cut at the highest profit, while after 80 years the investment compounds so heavily as to make it improbable that increasing stumpage values will compensate.

Three interest rates have been used in the first table to follow: 4, 5 and 6 per cent, compound. Forest calculations at lower rates are often seen, but it is not believed that less than 5 per cent will be satisfactory to private owners and many will insist on 6 per cent. The fair standard is what the owner can make in other business today, and since he can reinvest his income in the same business, it is reasonable to figure at a compound rate. A few examples are given to show how similar calculations may be made with any set of investment and stumpage factors which appeal to individual judgment. The second table, prepared from the first, shows at a glance the price that must be received for Douglas fir to make it pay either 5 or 6 per cent compound interest under a range of sixty different conditions of original investment and annual cost.

It should be borne in mind that, although present land value is made a charge, the value of the land at the time of harvest is not considered. This value is certain to increase greatly in the long periods involved. Taxation charges will be against it as well as against the timber. Indeed much land is now held without any regard to possible second growth. It should be a.s.sumed therefore that any profit in forest investment shown will be _increased_ by the sum obtainable for the land at the end of the same period.

Cost per M of growing Cost per M of growing Douglas fir resulting Douglas fir resulting from every $1 per acre from every 1 cent per acre originally invested. of annual carrying charge.

--------At the end of--------- --------At the end of--------- 50 60 70 80 50 60 70 80 Years. Years. Years. Years. Years. Years. Years. Years.

At 4% $ .35 $ .30 $ .33 $ .41 $ .074 $ .068 $ .078 $ .098 At 5% .56 .53 .65 .88 .102 .101 .126 .172 At 6% .90 .94 1.27 1.87 .142 .152 .208 .309

Example 1: With land worth $2.50 an acre at present, and an estimated carrying charge of 3 cents a year for protection and 20 cents per taxes, what stumpage price for a 50-year crop will pay 5 per cent compound interest? 6 per cent?

5% 6% 2-1/2 X .56 = $1.40 2-1/2 X .90 = $2.25 23 X .102 = 2.35 23 X .142 = 3.27 ----- ----- $3.75 $5.52

Example 2: With land worth $5 an acre at present, and stumpage estimated to reach $7.00 in 60 years, what is the maximum annual carrying charge per acre which can be paid during this period and permit a 5 per cent return? A 6 per cent return?