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The Work and Influence of C.D.F.REVENTLOW

in Danish Forestry


In 1784 when C. D, F. REVENTLOW, as head of the Exchequer, was able to influence decisively the legislation made by the absolute monarch the forests of Denmark were, to a very large extent, in a miserable condition. This was the result of centuries of inconsiderate fellings, failure of regen≠eration and cxcessive grazing by cattle.

Soon after the establishment of the absolute monarchy in 1660, attempts were made to form a definite forest policy but this had little positive result.

The first royal decree regarding the treatment of the forests dates from 1670. It begins with the following admonition: .Inasmuch as it has come to Our knowledge that the forests of Denmark, Our Kingdom, perceptibly decrease and deteriorate, due to unlawful and unwarrantable fellings and to the great negligence hitherto shown on all sides, for hardly any person has shown eagerness or desire to renew the forests by planting or propagation, We, in order to preserve and save from complete destruction one of the greatest glories which, thanks to God and Nature, has been bestowed upon Our Kingdom, have graciously presumed to draw up and formulate the following Forest Ordinance for Our Kingdom of Denmark..

A general writ prohibiting the clearance of forest land was issued in 1681, with a threat of loss of right of possession if the writ were violated.

Further royal forest decrees were issued in 1687, 1710, and 1733. A special decree on the planting of young forests was issued in 1696. In 1720 a French forester was appointed to introduce rational regeneration in the Royal Forests. The results were almost negative, mainly because the super≠vising staff of that time consisted chiefly of hunting men without proper knowledge of forestry.

Some initiative towards silviculture in the Royal Forests was taken in 1763 by bringing the Brunswick forester, JOHANN GEORG v. LANGEN (1699.1776) to Denmark to make management plans for the Royal Forests in North Zealand, according to the principles in use in many German states. In a few years the forests were surveyed and divided into so-called .annual coups.. Extensive clear fellings were made followed by reforestat≠ion by sowing or planting. Many tree species not native to Danish forests were used including the common European conifers, Norway Spruce, Silver Fir, Scots Pine, and European Larch. These specics have later taken an important place in Danish forestry.

VON LANGEN.S activities, which eventually became of such great value to Danish forestry, were not at the time appreciated by the government because of the expense his plans caused the Royal Exchequer. XVhcn VON LANGEN died in 1776 all his plans were suspended.

At the same time however, forestry in privately owned forests came under the influence of the new German principles incorporated in the high forest system. For this the Hanoverian forester, GEORG WILHELM BR‹EL (I 752-1829) is largely responsible. In 1777 BR‹EL † was sent to Denmark by Count HARDENBERG, later Prussian Lord Chancellor, to work out management plans for the forests on the Hardenberg estates. The main estate Harden-berg was adjacent to C. D. F. REVENTLOW.S estates on Lolland and RE≠VENTLOW became acquainted with BR‹EL. The first result was the en≠gagement of BR‹EL to make working plans according to the high forest system for REVENTLOW.S forests on the Pederstrup and Christianssæde estates; and next to establish a lifelong co-operation and friendship between REVENTLOW and BR‹EL.

The man responsible for operations in the Royal Forests was Forest Conservator D. N. v. WARNSTEDT (1729.18O2). He advocated, as may be seen from a decree of 1781 regarding the management of the Royal Forests, the principles of regular fellings or high forest system but with considerable modification of the VON LANGEN annual coups. Large stretches should by no means be laid bare by clear cutting, natural regeneration of beech and oak should be favoured, and only limited plantings of exotic tree species should be made. VON WARNSTEDT also made a plan for the enclosure of the Royal Forests whereby these were released from all rights of felling and grazing belonging to the peasants and the forests were enclosed by raising of solid dikes. This change occurred during the years 1781-4788.

In the preface to his .Treatise on Forestry. REVENTLOW expresses his gratitude that, through BR‹EL, he became acquainted with the new ideas which were prevalent in the kading forestry circles of Germany. BR‹EL was a true adherent of G. L. HARTIG (1764.1837) and of the latter.s manage≠ment plans and silvicultural principles, using long rotations and light thinnings at long intervals.

During his travels abroad REVENTLOW had become acquainted with forestry in France and England and he greatly valued the writings of DUHAMEL DU MONCEAU and JOHN EVELYN. Of these two authors he makes a note on page xxii of the introduction to his private copy of EVELYN.S .Silva.: .Let he who wishes to study silviculture read Evelyn and Duhamel. With philosophic wisdom they both reaped knowledge from well judged experiences. They possess more real knowledge than is to be found in all the later complicated forest systems, which more greatly enrich the authors and their booksellers than the readers.. In REVENTLOW.S copy of .Silva. there are many marginal notes in his own handwriting.

REVENTLOW conceded that economic advantages might be gained from the German regular high forest system, but only when it was combined with frequent thinnings. To verify this hypothesis he began in 1793 in his own forests to fell old oaks and beeches and to record, not only the outer di≠mensions of the stem but also the course of the annual rings in cross sections at the butt and at increasing heights from the butt. He caused similar stem analyses to be made in the Royal Forests on Zealand and in Slesvig during the following years. In this way he collected data which, by the scientific standards of that time, was unique in making possible the calculation of the annual increment of a single tree and its dependence on the age of the tree, its size and its distances from the surrounding trees12.

REVENTLOW.S self-confident attitude towards the best known writers on forestry of his time is plainly indicated in a letter which he wrote late in his life (1816) to his sister the COUNTESS STOLBERG: .... I may not have read so many books as my colleagues in the science of forestry but I think I have read more deeply in Nature.s own book than most of them ... So long as the English and the French arc unwilling to learn anything from the Germans and vice versa, forestry will remain in a juvenile state and vanity and habit will prevent them all from seeking something superior from abroad. Had I tried to gather my knowledge from Denmark alone I should have been left in the rear; as it is, I flatter myself that I am in the van. ... God has blessed me in this matter by changing me from a blind follower of Cramer, Hartig, Burgsdorf and others into the guide of many who themselves are blind. They will have to follow me whether they will or not .13
REVENTLOW.S investigations on the growth of trees, however, had not the study of natural science as their only scope. The primary object of his investigations was the economics of forestry. On this he writes in a pre≠liminary report of his investigations on tree growth, which he published in 1811: .In the treatment of forests less care should be taken to obtain the greatest possible growth from individual trees than to develop the whole forest so that it will bring its owner the greatest possible economic return ... and bring it to that point where the growth increment of the forests will be so great that the owner can find no advantage in felling the forest as the increment shall be worth more than four percent of the value of the growing trees..

In this REVENTLOW shows himself to be half a century in advance of his time. The thoughts later expressed in M. R. PRESSLER.S (1815.1886) and FR. JUDEICH.S (1828-4894) papers on forest economics, in which the so-called .Bodenreinertragslehre. (the theory of soil rental) is formulated, are already found in REVENTLOW.S conception of the object of forestry.

For a century, in Germany as well as in the countries influenced by Gcrman forestry, there have been discussions and argument about the theory of forest economics and its application to practical forestry. The main reason is that in Germany the traditional technique used in silviculture has been considered infallible. It has been thought incompatible with the laws of nature that trees of a rather advanced age in a closed high forest stand can maintain an annual growth sufficient to give a normal rate of interest on the capital locked up in the standing trees. Thus it was not the silvicultural technique that ncedcd reform but the theory of forest economics which ought to be rejected. And it was rejected.

Contrary to these ideas REVENTLOW by sound reasoning saw the necessity for an analysis and reform of the technique of silviculture to raise production to a level which would satisfy all economic requirements. This led to a scientific study of the interdependence between annual increment and standing volume per unit area.

By the end of the eighteenth century the forests in Denmark were almost everywhere being devastated by uncontrolled cattle grazing and ruthless exploitation. REVENTLOW realized that if the remaining forests were to be saved, a form of silviculture must be introduced which would make forestry pay as a going concern. He believed that the basis for this could be found in the German regular high forest system. Furthermore his investigations on growth of trees clearly indicated that a combination of the German system with heavy, often re≠peated, thinnings would render the high forest system more advantageous and make it possible within a comparatively short rotation to produce trees of satisfactory dimensions for all technical purposes.

His investigations on growth must have been completed about 1800, for REVENTLOW was by then working on his .Treatise on Forestry.. The matter must have been close to his heart, for, in spite of his extensive work in the scrvice of the state he allowed himself time for these studies. In a letter to his oldest son, dated April 3., 1801, written during the attack on Copen≠hagen by the British fleet when a bombardment of the city was in prospcct, he asks his son, in case of his death during the bombardment, to seek among his papers for .my forestry plan.. In the same year on the 22nd of May he lectured as an honorary member of the Royal Danish Academy of Sciences and Letters on .how valuable knowledge of the growth and culti≠vation of trees is obtained and utilized for the correct and most advan≠tageous treatment of the forests so that greater profit may be derived there≠from..

However many years were to pass before REVENTLOW.S .Treatise on Forestry. was ready for the printer, and when it finally, about 1816, was finished he could not afford to have it printed.

For twenty-nine years, from 1784 to 1813, REVENTLOW was one of the leading members of the government. During this period the great agrarian reforms were carried through and in forestry also many new ideas and principles were introduced on his † initiative. In 1785 advanced education in silviculture was established, and in 1788 a start was made in the af≠forestation of the barren heaths of Jutland at government expense. A decree was issued in 1792 to mitigate sand-drift along the Danish coasts and ex≠perimental tree planting on certain sand dune areas was begun. In 1799 it was decided that the great head of game in the Royal Forests should be reduced and silviculture made the primary aim of the Royal Forests. By 1800 an academic forestry course was required in the curriculum of the University of Copenhagen. The year 1804 saw the approval of a working plan for the management of the Royal Forests on the principles of the regular high forest system. In the year 1805 was issued a new Royal Forest Ordinance concerning the separation of land and secondary rights in the forests, the enclosure, and the management of the private forests. This Ordinance was largely drawn up by REVENTLOW himself. He considered it only as a temporary measure to prevent the continued ruthless exploi≠tation of private forests until the forest owners, after the introduction of an improved management of the forests, could be brought to understand that rational forestry is also good business.

The Ordinance of 1805 remained effective until 1937 when it was super≠seded by the present Danish Forestry Act. This Act contains, in reality, no new principles and it is primarily a modern version of the Forest Ordi≠nance of 1805. Thus Danish forest policy continues to rest on REVENTLOW.S fundamental work.

It was not until after 1813, when REVENTLOW had retired as Lord Chancellor, that he was able to concentrate on the final version of his great .Treatise on Forestry.. However, to print so comprehensive a work with the many tables, woodcuts and engraved plates was a costly affair, and because of the serious agricultural crisis which followed the bankruptcy of the state in 1813, REVENTLOW was, in spite of his extensive landed pos≠sessions, a poor man.

By 1816 the copper plates to illustrate the treatise were ready, but REVENTLOW.S finances were then so involved that on his birthday he prayed that .God may grant to mc and mine the daily bread until death..

In 1821 he refers to the economic difficulties of printing the long-com≠pleted forest treatise; nor did he live to see these difficulties overcome.

As late as 1824, at the age of seventy-six, REVENTLOW caused 73 oaks and bceches from young stands in the forests of Christianssæde to be felled anti the stems analyzed. The idea was, presumably, to obtain material to prove the beneficial effects of the heavy thinnings he had made in these stands since about 1800. The report of these investigations is to be found today in the archives of Brahetrolleborg Castle.

In these stands REVENTLOW, himself, marked the trees for some seven thinnings. Today in the Reventlow Museum at Pederstrup may be seen thc marking axe which he used. One side of the blade is shaped like a small hatchet, and the other side is a stamping hammer with the initials G. R. (Grey Reventlow).

In 1826 REVENTLOW proposed in a direct appeal to the King that the treatment used in the Reventlow forests should be submitted to a careful examination by the highest royal forest officials with a view of future man≠agement of the Royal Forests by REVENTLOW.S principles. This proposal was immediately accepted<. However, the final decision was not made until after REVENTLOW.S death in a Resolution of the Exchequer dated July 14., 1829. In this it is stated that the principles of thinning recommended by REVENTLOW may be considered worthy of being followed in the manage-ment of private forests where the question of a profitable return is important. In the Royal Forests, however, where forest management is not a question of obtaining the greatest amount of money but the highest production of wood, those principles should not be recommended. This resolution delayed the introduction of REVENTLOW.S improved management to the Royal Forests for a quarter of a century.18
Nevertheless REVENTLOW.S ideas on forest management were not entirely forgotten. In his own forests and those of his brother on the Brahetrolleborg estate they were respected and followed.

The Brahetrollcborg forests were managed by C. V. OPPERMANN (1784 1861), a very skilful forester. He had been called from Hanover in 1806 to act as forester and he remained in the service of Brahetrolleborg until 1857.

OPPERMANN was a confirmed advocate of REVENTLOW.S principles of forest management. In 1836 he published an important paper on the relation between tree growth and rate of interest.20 Here he proved by increment data and the accounting records from the Brahetrolleborg forests that RE≠VENTLOW.S calculations of the expected returns from an improved forest management were not hypothesis but reality.

One of the first sample plots of oak which OPPERMANN laid out about 1812 in a young oak stand raised by direct sowing in 1785 on old farm land still exists. It is presumably the oldest existing forest sample plot.

It was only after 1879 when REVENTLOWS .Treatise on Forestry. had, at the instance of P. E. M‹LLER, appeared in print that REVENTLOW. S thinning theories were generally accepted in Danish forestry. The Danish method of thinning based on REVENTLOW.S principles has since aroused greater and greater interest both at home and abroad.

The question of the choice of method and grade of thinning is still a central problem in all systematic Ibrest managemeht. The literature on the subject in Danish and in other languages is so extensive that it is not possible here to summarize even the most of the articles dealing of the many articles dealing with the Danish method of thinning
Here should only be cited what A. F. BERGSOE wrote in his compre≠hensive biography of REVENTLOW published in 1837: .It is not only on account of his practical activities and his services to Danish forestry that Reventlow.s name will be remembered with honour in the annals of our forests but also for the very important results of his many years of scientific study, experimentation and investigations in forestry. If indeed his theories will continue to be confirmed, as has been the case in the few places where they have been followed, these theories will form an epoch in the forestry of our own and of all other countries..

This prophecy may truthfully be said to have been fulfilled.