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
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
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
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
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
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
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
It was only after 1879 when REVENTLOWS .Treatise on Forestry. had, at
the instance of P. E. M‹LLER, appeared in print that REVENTLOW.
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
This prophecy may truthfully be said to have been fulfilled.