Part 8

In the development of the shelterwood system there was at first, under the lead of Hartig, a tendency to open up rather sharply, taking out about three-fourths of the existing stand, but gradually he became convinced that this was too much, and finally reduced the first removal to only about one-third of the stand. This was the origin of his nickname of _Dunkelman_. In spite of the fact that it was claimed that Cotta took the opposite view (for which he was called _Lichtman_), he, too, grew to favor a dark position, and, as he progressed, leaned more and more towards more careful opening up. Hartig originally recognized only three different fellings: the cutting for seed; the cutting for light; and the removal cutting. By and by, a second cut was made during the seed year, and the number of fellings to secure gradual removal were increased, so that, by 1801, this system seems to have been pretty nearly perfected to its modern conditions. The best exposition of this _Femelschlagbetrieb_ (shelterwood system), as then developed, is to be found in Karl Heyer’s Handbook, 1854.

The method was unfortunately extended by Burgsdorf (1787) to the Northern pineries with a seventy year period of rotation. Within ten years, however, he recognized its inappropriateness, and modified it by instructions to leave only six to twelve seed trees per acre. His successor, Kropff, reduced the number of seed trees to four or five, which were to be removed within two or three years. In spite of the development of this more rational method, the practitioners under Hartig’s approval, held mainly to a dark position even for pine, much in the manner of a selection forest, which produced a poor growth of oppressed seedlings, retarding for a long time the development of the pineries.

In spruce or fir, either a pure selection forest or a strip system was employed. Attempts at a shelterwood system were made, but experience with the wind danger soon taught the lesson that this was not a proper method with shallow-rooted species. Even Hartig preferred for spruce clearing and planting, and this is still the most favored method with that species. For the deep-rooted and shade-enduring fir the shelterwood method with a long regeneration period was thoroughly established in the Black Forest, and in Württemberg by 1818.

Natural regeneration being the main method of reproduction until the beginning of the 19th century, _artificial_ means, as is evident from the forest ordinances of Prussia and Bavaria (1812 and 1814), were usually applied only to repair fail-places, or to plant up wastes. In this artificial reforestation, with the exception of the planting of oak in pastures, sowing was almost entirely resorted to because it could be done cheaper and easier, but as the sowings were mostly made on unprepared soil and with very large amounts of seed (30 to 60 pounds per acre, now only 7 to 10 pounds), the results were not satisfactory, either because the seed did not find favorable conditions for germinating, or when germinated the stand was too dense.

Planting, if done at all, was done only with wildlings dug from the woods, and usually, following the practice of the planting of oak in pastures, with saplings: the plant material was too large for success. Nurseries, except for oak, were not known, even to Cotta in 1817; and Heyer, having to plant up several thousand acres, still relied on wildlings, two to three years old, which he took up with a ball of earth by means of his “hole spade,” a circular spade re-invented by him and much praised by others. Hartig, in 1833, still advised the use of four to five year old pine wildlings, root-pruned, but, eventually, having met with poor success, for which he was much discredited, came to the conclusion that un-pruned two-year-old plants were preferable.

The credit of having radically changed these practices belongs to Pfeil, who, entirely reversing his position, advocated for pine forest a system of clearing followed by sowing, or by planting of wildlings with a ball of earth. Then, suggesting that possibly planting without this precaution could be attempted, and pointing out the necessity of securing a satisfactory root system, he recommended, about 1830, the use of one-year-old seedlings grown in carefully prepared seed beds. While for securing these, he relied upon the simple preparation of the soil by spading, _Biermans_ added the use of a fertilizer in the shape of the ashes of burned sod. The method of growing pine seedlings and planting them when one to three years old was further developed by _Butlar_ (1845), who introduced the practice of dense sowing in the seed beds. He also invented an ingenious planting iron or dibble, a half cone of iron, which was thrown by the planter with great precision, first to make a hole and then to close it. This was improved by the addition of a long handle into the superior, well-known and much used _Wartenberg_ planting dibble. At the same time (1840), _Manteuffel_ devised the method known by his name of planting in mounds, which is especially applicable on wet soils.

It was not until 1840 that transplanting of yearling pines with naked roots became general. The widespread application of this latter system resulted in abandoning to a large extent mixed growth, and led to the establishment of pure pine forests, introducing thereby most intensively all the dangers incident to a clearing system and pure forest which are avoided by the mixed forest, namely, insects, frost and drought.

A practice of planting spruce in bunches, originally twelve to twenty plants in a bunch, had been in existence since 1780. This practice increased until 1850, and is still in use in the Harz mountains and in eastern Prussia, although the bunches have been reduced so as to contain only from three to five plants, the object of the bunching being to make sure that one or the other of the plants should live. Much discussion as to the merits of this method took place between the old masters, Cotta favoring the small bunches upon the basis of a successful plantation of his own, Hartig and Pfeil opposing it, but finally weakening. Since 1850, however, the practice of setting out single plants has become more general.

A reaction from the indiscriminate application of the shelterwood method to the hardwoods and of the clearing method to the pine set in during the last quarter of the 19th century under the lead of Burkhardt and Gayer. These advocated return to mixed forest and to natural regeneration with long periods, approaching a selection forest. Gayer especially, professor of silviculture at Munich, became the foremost apostle of this school. Yet even to this day, the principles of silvicultural treatment under the many different conditions remain unsettled. On the whole however, with the financial question assiduously brought forward, the clearing system has made most progress, and the selection system has nearly vanished, being replaced by the group method and the shelterwood system.

A number of special forms of silvicultural management applicable under special conditions have been locally developed, without, however, gaining much ground and being mainly of historical value. Among these may be mentioned _Seebach’s Modified Beech Forest_, which consists in opening up a beech stand so as to secure regeneration, merely to form a soil cover, leaving enough of the old stand on the ground to close up in thirty or forty years. By this treatment the large increment due to open position is secured without endangering the soil. Similarly the _Storied_ or _Two-aged High forest_, was applied to the management of oak forest in mixture with beech. In a few localities also, on limited areas, a combination of forest and farming (_Waldfeldbau_) has been continued and elaborated, besides the more general use of coppice and coppice with standards.

According to the statistics for 1900 the following distribution of the acreage under different silvicultural methods prevailed throughout the empire:

Deciduous Coniferous Per cent. Per cent. Total Forest 32.5 67.5 High Forest 18.4 60.1 Selection Forest 2.3 7.4 Coppice 6.8 -- Coppice with standards 5. --

Coniferous forest, of which 68% is pine and 30% spruce, prevails in Eastern and Middle Germany, deciduous forest, of which 20% is oak, the balance principally beech, in the West and South.

Coppice and coppice with standards are mostly in private hands as well as the coniferous selection forest, the State forests being almost entirely high forest, i.e., seed forest, other than under selection method.

_Methods of Improving the Crop._ The credit of having first systematically formulated the practice of thinnings under the name of _Durchforstung_ (for the first thinning), _Durchplenterung_ (for the later thinnings), belongs to Hartig, although the practice of such thinnings had been known and applied here and there before his time. He confined himself mainly to the removal of the undesirable species, dead and dying, suppressed and damaged trees, being especially emphatic in his advice not to interrupt the crown cover. Excepting the early weeding or improvement cuttings, these thinnings were not to begin until the fiftieth to seventieth year in the broadleaved forest, but in conifers in the twentieth to thirtieth year.

The first attempt to explain on a biological basis the process and effect of thinning was made by Späth in a special contribution (1802). Cotta, in his Silviculture, although at first agreeing with Hartig, later in his third edition (1821) changes his mind, and improves both upon the biological explanation of Späth and the practice of Hartig, pointing out that the latter came too late with his assistance, that the struggle between the individuals should be anticipated, and the thinning repeated as soon as the branches begin to die; but he also recognizes the practical difficulty of the application of this cultural measure on account of the expense. Curiously enough, he recommends severer thinnings for fuel-wood production than for timber forests.

Pfeil accentuates the necessity of treating different sites and species differently in the practice of thinnings. Hundeshagen accentuates the financial result and the fact that the culmination of the average yield is secured earlier by frequent thinnings. Heyer formulates the “golden rule:” “Early, often, moderate,” but insists that first thinning should not be made until the cost of the operation can be covered by the sale of the material. Propositions to base the philosophy and the results of thinning on experimental grounds rather than on mere opinion were made as early as 1825 to 1828, and again from 1839 to 1846, at various meetings of forestry associations, until, in 1860, Brunswick and Saxony inaugurated the first more extensive experiments in thinnings. The two representatives of forest finance, Koenig and Pressler, pointed out, in 1842 to 1859, the great significance of thinnings in a finance management as one of the most important silvicultural operations for securing the highest yield.

In spite of the advanced development of the theory of thinning, the practice has largely lagged behind, because of the impracticability of introducing intensive management. Only lately, owing to improvement in prices and the possibility of marketing the inferior material profitably enough to justify the expenditure, has it become possible to secure more generally the advantages of the cultural effect. Within the last thirty or forty years, great activity has been developed among the experiment stations in securing a true basis for the practice of thinning.

New ideas were introduced through French influence and by others independently in the latter part of the eighties, when the distinction between the final harvest crop (Fr. élite, le haut) and the nurse crop (le bas) was introduced.[4]

[4] The conception of such subdivision and the English nomenclature was independently first employed by the writer in his Report for 1887, as Chief of Forestry Division, when discussing planting plans for the prairies.

The physiological reasons for the practice of thinning upon experimental basis, were advanced by the botanists Goeppert and R. Hartig, and among foresters, the names of Kraft, Lorey, Haug, Borggreve, Wagener, and others are intimately connected with the very active discussion of the subject lately going on in the magazines. Thinnings have become such an important part of the income of forest administrations (25 to 40% of the total yield) that the prominence given to the subject is well justified, and a more modern conception of the advantages of thinnings and especially of severer thinnings is gaining ground.

The proposition, now much ventilated, of severe opening up near the end of the rotation, in order to secure an accelerated increment (_Lichtungshiebe_) is, however, much older; Hossfeld, in 1824, and Jäger in 1850, advocated this measure for financial reasons, while Koenig and Pressler anticipated the development of an individual tree management by pruning, and differentiation of final harvest and nurse crop, a method which is working itself out at the present time.

5. _Methods of Forest Organization._

As stated before, to Hartig and Cotta belongs the credit of having applied systematically on a large scale methods of forest organization for sustained yield; Hartig having been active in Prussia since 1811, and Cotta beginning to organize the Saxon forests in the same year. The method employed by Hartig, the so-called volume allotment, had been already formulated and its foundation laid by Kregting and others (although Hartig seems to have claimed the invention). But it was reserved to Hartig to build up this method in its detail, and to formulate clearly and precisely its application, as well as to improve the practice of forest survey, calculation of increment, and the making of yield tables. His method involved a survey, a subdivision, a construction of yield tables and the formulation of working plans, in which the principle according to which the forest was to be managed during the whole rotation was laid down for each district. The rotation was determined, divided into periods, finally of twenty years, and the periodic volume yield represented by all stands was distributed through all the periods of the rotation in such a manner as to make the periodic felling budgets approximately equal; or, since the tendency to increased wood consumption was recognized, an increase of the felling budget toward the end of the rotation was considered desirable.

Cotta based his system of forest organization upon a method described by a Bavarian, Schilcher (1796); it relied primarily upon area rather than volume division. This method was later on (1817), called by him _Flaechenfachwerk_ (area allotment). It divides the rotation into periods and allots areas for each periodic felling budget. But before this time, in 1804, Cotta had himself formulated a method of his own, which combined the area and volume method, the volume being the main basis and the area being merely used as a check. While Hartig dogmatically and persistently carried out his difficult scheme, Cotta was open-minded enough to improve his method of regulation, and by 1820, in his _Anweisung zur Forst-Einrichtung und -Abschaetzung_, he comes to his final position of basing the sustained yield entirely on the area allotment, using the estimate of volume simply to secure an approximately uniform felling budget. He laid particular stress on orderly procedure in the subdivision and progress of the fellings. He did not prepare an elaborate working plan binding for the entire rotation, but merely prescribed the principles of the general management, and, after 1816, he confined the formulating of felling and planting plans only to the next decade.

A similar method, making a closer combination of volume and area allotment, now known as the combined allotment, in which the area forms the main basis for distributing the felling budgets, was prescribed by Klipstein in 1833. This, also, confines the working plan to the first period of the rotation and for this period alone makes a rather careful statement of the expected volume budget; a new budget is then to be determined at the beginning of the next period. This idea of confining the budget determination to a comparatively short period is now generally accepted, the future receiving only summary consideration.

These methods of organization were the ones generally applied in practice, and are still with some modifications in practical use. About 1820, however, new theories were advanced which led to the formulation of methods based upon the idea of the _normal forest_. The conception of a normal forest, with a normal stock, distributed in normal age classes, so as to insure a sustained yield management, was evolved, in 1788, by an obscure anonymous official in the Tax-collector’s office of Austria, designed for assessing woods managed for sustained yield. This fertile idea, which is still the basis of forest organization in Austria, and explains better than any other method the principles involved in forest organization, did not find entrance into forestry literature in all its detail until 1811 when André compared this so-called _Cameraltaxe_ with Hartig’s method of regulation. We find, however, that, simultaneously with the Austrian invention of this method, Paulsen (1787) proposed to determine the felling budget as a relation between normal stock and normal yield, and in his yield tables (the first of the kind, 1795), he gives the proportion of increment to normal stock in percentic relation, so that the felling budget may be either expressed as a fraction of the stock or as a per cent.; in beech forests, for instance, he determines the felling budget as 3.3% on best sites, 2.5% on medium, and 1.8% on poor sites.

Probably stimulated by André’s description, _Huber_ (1812) developed a method and formula which may be considered the foundation of the later development by Carl Heyer (Felling budget = I + ((Sa - Sn)/e)).

Based upon the normal forest idea, a number of methods were elaborated which, because of their employing a mathematical formula for the determination of the felling budget, are known as _formula methods_; they are, indeed modified rational volume divisions.

Hundeshagen has the merit of having first clearly explained the basis of these methods, and himself developed a formula, of the correctness of which he was so convinced as to designate his method as “the rational” one. Two other formulæ were brought into the world by Koenig (1838-1851), but the credit of the most complete elaboration both of the principles of the normal forest idea and of its practical application belongs to Carl Heyer. The principles of his method are briefly: First determine upon the period of regulation during which the abnormal forest is to be brought nearer to normal conditions; the length of this period to be determined with due regard to the financial requirements or ability of the owner and to the conditions of the forest. The actual stock on hand is then determined and the total increment, based on the average increment at felling age of each stand, which will take place during this period, is added. Deducting from this total what has been calculated as the proper normal stock requisite for a sustained yield management, the balance is available for felling budgets which may be utilized in annual or periodic instalments during the period of regulation. A working plan is provided which takes care of securing an orderly progress of fellings and proper location of age classes, to be revised every ten years.

Although this is undoubtedly the most rational method yet devised, it has remained largely unused, and is found in somewhat modified application only in Austria and Baden.

An entirely new principle in the theory of forest organization was introduced, when the aim of forest management was formulated to be the highest soil rent. According to this requirement the proper harvest time of any stand, or even of any tree, was to be determined by the so-called index per cent., that is, a calculation which determines whether a stand or a tree is still producing at a proper predetermined rate, or is declining. The advocates of this principle were especially _Pressler_ (professor of mathematics at Tharandt, 1840 to 1843) and _G. Heyer_, son of Carl Heyer, who based his method on his father’s formula, merely introducing values for volumes. _Judeich_, director of the Tharandt school, also developed in the sixties a method, based upon financial theory, which is to attain the highest rate per cent. on the capital invested in forest production. On the basis of survey and subdivision of working blocks composing a felling series, and with a rotation determined by financial calculations with interest accounts, he makes a periodic area division for determining the felling budget in general, and in addition employs the index per cent., as explained, for determining in each allotted stand the more exact time for its harvest.

While these men pleaded for a strict finance calculation, such as is properly applied to any business making financial results the main issue, the defenders of the old regime, which sought the object of forest management mainly in highest material or value production, advanced as their financial program the attainment of the highest forest rent as opposed to the highest soil rent. They neglected and derided the complicated interest calculations which have to take into consideration uncertain future developments, and were satisfied with producing a satisfactory balance, a surplus of income over expenses, no matter what interest rate on the capital involved in soil and forest growth that might represent.

At the present time these financial propositions are still mainly under heated discussion.

In actual practice, the various state forest administrations, with the exception of the Saxon one, continue to rely upon the older methods in regulating the management of their forest properties without reference to financial theories. This is largely due to momentum of the practical existence and application of these methods in earlier times and the difficulty and impracticability of a change. Just now, however, several of the State administrations are preparing to radically revise their working plans.

In Prussia, the instructions for working plans of 1819 formulated by Hartig were improved upon by his successor, Oberlandforstmeister _von Reuss_ (1836), and these instructions formed the basis of the work of forest regulation until the end of the 19th century. It is a periodic area allotment with only a summary check by volume. The working plan is only to secure a rational location and gradation of age classes; the calculations of yields and specific rules of management are lately confined to the first period and are revised every six years.

In Saxony, Cotta’s area method was systematically developed, and, as the larger part of Saxon forests is coniferous, mainly spruce, the proper location of age classes forms a special consideration for the progress of fellings. The determination of volume and increment was left to summary estimates, and the area division became entirely superior. The original idea of Cotta that orderly procedure in the management is of more importance than the actual determination and equalization of yield still pervades the Saxon practice. Since 1860, an attempt has been made to calculate the rotation and determine the felling budget on the principle of the soil rent, at least as a corrective of the annual budget, and in general to lean towards Judeich’s stand management.

In Bavaria, after various changes, a complete allotment method of area and volume had come into vogue, in 1819; but, at the present writing (1911) an entirely new and modern re-organization has been begun, in which most modern ideas and especially much freedom of movement, even to deviation from the principle of sustained yield, is allowed.

In Württemberg, where, in 1818 to 1822, a pure volume allotment had been introduced, in 1862 to 1863 the combined allotment method was begun, the felling budget being determined in a general way for the next two or three periods, and more precisely for the first decade, without attempting more than approximate equality.

In 1898, new instructions were issued, which abandon the allotment method and restrict the yield regulation to designating felling areas for the first period.