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Lunar Rhythms In Forestry Traditions – Lunar-Correlated Phenomena In Tree Biology And Wood Properties

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For more than 2000 years, certain forestry practices andrules regarding tree felling have been carried out in observance to Moon cycles. A general review of the differenttypes of rules followed (known in Europe and on other continents and stemming from both written sources andcurrent practitioners) shows that special timber uses are mentioned in relation to a specific felling date whichsupposedly ensures advantageous wood properties. These empirical forestry traditions apply to a range ofwood uses as diverse as building timber, shingles, wooden chimneys, fuel wood, resonance wood for harmonytables of violins, cheese-boxes, barrels and ploughs. In each of these cases, felling at the “right date” isthought to be an important factor to ensure the required properties of the product. Moreover, the rafting of timber used tobe limited to certain days of the Moon cycle, when the water was supposed to carry the wood in the best way. The second part presents scientific studies concerned,on the one hand, with “Moon phases” factor. They deal with elements of tree biology such as germinationand initial growth of tropical trees (where strong and systematic variations and their complicating aspectshave been observed), insect attacks on trees and reversible fluctuations of stem diameters. On the other hand, someworks concentrate on wood properties and the relation between wood and water. They deal with the durabilityof wood, with systematic density variations after kiln-drying and with variations in the compression strength of the corresponding samples.An overview tries to find a common link between empirical practicesand the scientific results.
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LUNAR RHYTHMS IN FORESTRY TRADITIONS
LUNAR-CORRELATED PHENOMENA IN TREE BIOLOGY AND
WOOD PROPERTIES
ERNST ZÜRCHER
Wood Sciences, HG F.21, Department of Forest Sciences, Swiss Federal Institute of Technology
Zurich, ETH-Zentrum, CH-8092 Zürich, Switzerland (E-mail: ernst.zuercher@swood.bfh.ch)
Abstract. For more than 2000 years, certain forestry practices and rules regarding tree felling have
been carried out in observance to Moon cycles. A general review of the different types of rules
followed (known in Europe and on other continents and stemming from both written sources and
current practitioners) shows that special timber uses are mentioned in relation to a specific felling
date which supposedly ensures advantageous wood properties.
These empirical forestry traditions apply to a range of wood uses as diverse as building timber,
shingles, wooden chimneys, fuel wood, resonance wood for harmony tables of violins, cheese-boxes,
barrels and ploughs. In each of these cases, felling at the “right date” is thought to be an important
factor to ensure the required properties of the product. Moreover, the rafting of timber used to be
limited to certain days of the Moon cycle, when the water was supposed to carry the wood in the best
way.
The second part presents scientific studies concerned, on the one hand, with “Moon phases”
factor. They deal with elements of tree biology such as germination and initial growth of tropical trees
(where strong and systematic variations and their complicating aspects have been observed), insect
attacks on trees and reversible fluctuations of stem diameters. On the other hand, some works con-
centrate on wood properties and the relation between wood and water. They deal with the durability
of wood, with systematic density variations after kiln-drying and with variations in the compression
strength of the corresponding samples. An overview tries to find a common link between empirical
practices and the scientific results.
Keywords: Chronobiology, felling date, Moon phases, traditional forestry, tree biology, wood
properties
1. Introduction
The topic presented here is related to the fact that most organic processes and the
structures which result from them have a rhythmic character. In the plant world in
temperate latitudes, it is immediately obvious that the germination, growth, matura-
tion and perennial structure formation in trees are marked by an alternation between
active and resting phases. This alternation is materialized in the morphology of the
shoot or in the architecture of the tree, and on an anatomical level, in the succession
and internal structure of the growth rings.
Earth, Moon and Planets 85–86: 463–478, 2001.
© 2001 Kluwer Academic Publishers. Printed in the Netherlands.
464 ERNST ZÜRCHER
Man, a heterotrophic being has always had to take into account this rhythmical
characteristic of plants, for his subsistence.
When reading works which deal with popular sayings or quote classical au-
thors concerning agricultural practice, or simply speaking to gardeners, farmers
or foresters with an empirical experience based on tradition, one is struck by two
things.
Firstly, in addition to the rhythm of the seasons, lunar rhythms are systematic-
ally mentioned as having an influence on the growth, structures, characteristics or
properties of plants.
Secondly, a number of practices show certain common elements, despite the
geographical distance of the sources; these similarities in the rules formulated
would seem to suggest the existence of possible objective phenomena. For ex-
ample, the general rules governing the felling of trees are in accordance right across
the continents; whether in the alpine arc (Hauser, 1973), in the Near East, in Africa,
India, Ceylon and Brasil, or in Guyana, all these traditions seem to be based on
matching observations (Broendegaard, 1985; other sources: See Zürcher, 2000). It
should be noted that in the past, people had more time and more peace and quiet to
observe: it must even have been of vital importance to them.
These facts and observations certainly had their share of superstitions added
on to them, as soon as the precise and objective observations were forgotten, as
soon as people trusted blindly in traditions, without having any longer access to
an understanding of the phenomena themselves. This appears clearly in certain
sayings which make diametrically opposed assertions about the same subject, as
can be found, for example, in the very complete book by Hauser (1973) about
peasant rules in Switzerland. As for the influence of the Moon, the similarities in
the traditional rules can be resumed thus at a first and empirical level:
“The Moon is strongly connected with water; the full Moon brings more water
to the plant than the new Moon” (Gabriel, 1988). “During the waning Moon, liquids
move towards the roots, the Earth is receptive, it breaths in; during the waxing
Moon, on the other hand, the sap tends to rise, and upward growth and breathing
out predomine” (Paungger and Poppe, 1991).
Pliny already reduced the phenomenon to its most utilitarian aspect. He advised
Roman farmers to pick fruit for market before the full Moon, as it weighed more,
but to pick fruit for their own stores at the new Moon, as it would last better.
Elsewhere, he recommends felling trees at the new Moon (Storl, 1992).
The determination of “the right felling date”, according to ancient traditions or
to oral communications referring to the Moon, corresponds to 3 types of rules:
1. According to the synodic lunar rhythm, linked to the Sun–Moon–Earth re-
lationship; the passage of the new Moon (Sun–Moon conjunction) through
the first quarter to the full Moon (Sun-Moon opposition), then through the
third quarter to return to the initial phase represents the lunation and lasts
29.531 days; traditions speak of “waxing Moon/waning Moon” [German
“zunehmend/abnehmend”]
LUNAR RHYTHMS IN FORESTRY TRADITIONS 465
2. according to the tropical lunar rhythm, related to the Earth–Moon relation-
ship from a geocentric point of view; the Moon’s trajectory takes it higher
in the sky (compared to the Earth’s horizon) for 13 or 14 passages, then the
movement is reversed for the other half of the tropical month, which lasts
for 27.32158 days; traditions speak of “ascending Moon/descending Moon”
[German “aufsteigend/absteigend”]
3. according to the sidereal lunar rhythm, whose periodicity is very close to the
tropical one; this cycle concerns the constellations of the zodiac before which
our satellite passes during a rotation around the Earth, and the cycle lasts
27.32166 days; the highest point of the tropical cycle occurs in the constel-
lations of Gemini, the lowest point in Sagittarius. Traditions mention specific
“signs” [German “Tierkreiszeichen”] or groups from the 12 “signs” as having
a special influence on plants.
At stake here from the scientific point of view is the synodic lunar rhythm; much
less research has been carried out about the role of the two other rhythms in
biological processes.
2. Traditions Still Persisting (see rcher, 2000)
Moon-related rules affecting felling are still used by specialists who work with
wood today. In this article, certain examples taken from practice which are known
to the author at first hand or which come from reputable sources will be quoted,
without an evaluation of the resulting statements. The aim of this short section is to
demonstrate how this supposed level of effectiveness is put into use when working
with wood and in which areas of wood utilization.
2.1. C
ONSTRUCTION WOOD
A rule for felling which stems from France is “bois tendre en cours/bois dur en
décours”, which translated means: soft wood when waxing/hard wood when wan-
ing. The second type of wood is considered as adequate for construction. In the
Western Alps (Oberland/Pays d’En-Haut) a sawmill owner, who is an influential
personage, is advised by an old forester to keep a special assortment of “Moon
wood” for building of traditional chalets. In Austria a successful, internationally-
known family enterprise near Salzburg is worth mentioning. Here, slow-grown
mountain forest trees are felled at new Moon at the lowest point, and, additionally,
during a “warm sign” such as Sagittarius. Building timber of highest quality is
guaranteed. Reports from development work in Bhutan and Mali also mention the
felling of construction wood according to Moon phases. In Mali the rule is “Tu
coupes l’arbre pendant la lune vide” (You fell the tree when the Moon is empty
then the wood is thought to be resistent against termites).
466 ERNST ZÜRCHER
2.2. SHINGLES
In Pays d’En-Haut a young, recognised shingle-layer reports interesting experi-
ences related to Moon phases in connection with differences in discoloration and
durability. In the Black Forest (Schwarzwald), conifers felled during the appropri-
ate Moon phase provide shingles with a durability several times that of those from
trees felled at other times.
2.3. C
HIMNEYS
Originating from the Freiburg Pre-Alps (Teutlingen) and the Neuchâtel Jura (La
Recorne/La Chaux-de-Fonds) there are two old houses with wooden chimneys
which can be visited in Ballenberg/Bern (an open-air museum). According to local
reports, when building such chimneys wood from specific felling dates was used,
which is supposed to result in extremely re-resistant material. Ladders for fire-
rescue services used also to be manufactured from fire-resistant Moon-phase wood.
Larch in particular was often used for these purposes.
2.4. F
IREWOOD
In the Western Jura there is an old tradition which is still carried on today, whereby
wood for fuel should also be felled according to Moon phases. The opposite stated
to construction wood applies to rewood: “Le poinct de la lune est remarquable,
pour en croissant tailler le bois de chauffage, et en décours, celui des bastimens”
(ancient French rule) the phase of the Moon is worthy of notice, in order to fell
wood for fuel when waxing and for building when waning.
2.5. R
ESONANCE WOOD
The most valuable wood creations achieved through craftsmen’s skills may be
seen in the making of musical instruments, such as violins. In the famed alpine
forests near Klosters (Prättigau, Grisons), as also in Pays d’En Haut, some wood
wholesalers and also some instrument-makers wish to be present on the exact date
of felling, in order to guarantee the required quality for harmony tables. Here, not
only the Moon phase is important, but also the sign of the zodiac in which the
Moon is to be found. The wood thus obtained is supposed to dry particularly well
and therefore be especially light, with good acoustic properties.
2.6. C
HEESE PACKAGING BOXES
In the Western Jura certain sawmills are specialised in the production of cheese
packaging boxes for Vacherin cheese; a use of wood which requires a particularly
high level of resistance to fungi for food hygiene reasons. A specialist confirmed
that Moon phases were taken into consideration when felling the spruces and spoke
LUNAR RHYTHMS IN FORESTRY TRADITIONS 467
of “notebooks full of observations”, although he was not prepared to give away his
trade secrets in detail at the drop of a hat.
2.7. W
INE-BARRELS
Certain French coopers also use “Moon phase oakwood” – wood from trees felled
at special dates gives properly fitting and liquid(wine)proof staves. The maintained
difference (compared to “random” wood) may perhaps be analogous to fluctuations
in the porosity of oak wood according to the season of the year, which has been
experimentally established.
2.8. P
LOUGHS
The compliance with cosmic factors when working with wood is not limited to
Central Europe. In Bolivia, the Ketshua Indians (descended from the Incas) still
fell Thago-/Algarrobo-trees (Prosopis ferox) for the making of ploughs during the
first waning Moon after the start of spring (shortly before Easter celebrations). The
difference in aspects of quality such as durability or hardness is thereby taken for
granted.
2.9. W
OOD FLOATAGE
Even the transport of treetrunks along waterways used to be carried out according
to Moon rhythms, because changing trajectories could be observed during trans-
port. In Prättigau the rule was that wood should be floated at the descending Moon
(“nidschigentä”), because then the trunks would stay in the middle of the river.
3. Lunar-Correlated Phenomena in the Biology of the Tree (and the Seed)
The aim of research lies in the critical examination of a possible grain of truth
underlying the above statements and in understanding the phenomena which
could be responsible for the experiences described. Facts must be separated from
superstition.
In this paper, research results concerning trees and wood will be presented in
connection principally to the synodic Moon rhythm.
3.1. D
URABILITY OF OAK TRUNKS
During the reign of Louis XIV a royal forest order was passed stating that the
felling of wood should occur during a waning Moon between the falling of the
leaves and the new growth season (Müller, 1993). Between 1733–1735 this ruling
was critically examined by M. Duhamel du Monceau, General Inspector of the
French Navy and one of the fathers of tree biology, who believed it to be based on
468 ERNST ZÜRCHER
mere superstition. By comparing the decay-resistance of wood felled in the middle
of the waning Moon phase with that of wood felled at the middle of the waxing
Moon phase, he did contradict the existing rule, but at the same time he revealed
an unexpected other Moon-related phenomenon. The result was not merely neutral
regarding Moon phase, but rather “favoured the waxing Moon; a repetition of the
experiment also favoured the waxing Moon” (Knuchel, 1930). It must, however, be
noted that only an extremely small number of trees were included in the experiment
(three trees each, oaks approximately three feet thick) and that the sawn trunk
sections were kept “at different locations”. These two factors strongly question
the scientific correctness and objectivity of this research.
3.2. . . .
AND OF SCOTS PINE WOOD
Over a period of a complete year the decay-resistance of small samples from
standing trees (Pinus sylvestris), exposed to three wood-destroying fungi was es-
tablished. The samples were taken regularly each fortnight from 6 trees, at the
exact point of new Moon and full Moon and submitted to controlled fungi attack
(Wazny and Krajewski, 1984). When considering the level of destruction for the
whole period and the whole experiment, no systematic relation to Moon phases
could be recognised; only a (traditional and scientifically known) seasonal trend
was established.
If, however, the obtained values for destruction by Coniophora puteana,a
brown rot with the highest destruction rates for this experiment, are critically ex-
amined, it can be seen that over a period of four full months systematic fluctuation
was in evidence between full and new Moon (see Zürcher, 2000). A check by the
author of this article using a two-way-variance analysis confirms, on the one hand,
the seasonal trend in the period from the end of July until the end of November.
On the other hand, it also shows that during this period the destruction level for
full Moon samples is significantly lower than for new Moon samples. These Moon
phase fluctuations are not dependent on the general trend seen here (non-significant
interaction). Thus, a general rule could not be confirmed, but a relevant Moon-
chronobiological phenomenon occurs, which could be investigated in more depth
in future research projects.
It would have been more informative to take the samples in the waning and
waxing phases, instead of at full and new Moon exactly. This would have been
more appropriate to the content of the traditional beliefs. In addition, research on
germination and initial growth of trees has emphasised the importance of such
nuances (see following chapter).
3.3. I
NFESTATION BY BARK BEETLES
A confirmation of old rules regarding infestation by insects was obtained in ex-
periments covering a time period of several years with felled Spruce-trees at the
LUNAR RHYTHMS IN FORESTRY TRADITIONS 469
Institute of Forest Protection of the State Forestry Research Organisation Vienna-
Schönbrunn (Jahn, 1982). After a cooler period, the full Moon trees were clearly
favoured over the new Moon trees during initial attacks. Further, these differences
were connected to variations of “biophysical fields”, with a differentiation between
day and night at the level of the cambial chemistry.
3.4. G
ERMINATION AND INITIAL GROWTH
Under tropical conditions, as they were present at an experimental tree nursery
in Rwanda, an ideal situation for the investigation of Moon rhythms is given.
Temperature and daylight duration are more or less constant, and during the dry
period the plants can be watered. Over a period of three years a preliminary exper-
iment, a main experiment (12 sowings with 4 repetitions each) and a control- and
additional experiment were carried out. Sowing took place two days before full
Moon and two days before new Moon (Zürcher, 1992/Figure 1A). For Maesopsis
eminii germination and initial growth show a decided rhythmic character. Speed of
germination, rate of germination, average height and maximum height after four
months are thus systematically related to the timing of sowing in relation to the
Moon phase (better results were obtained when sowing before full Moon). These
results agree with earlier experimental values for annual plants. In this way, an old
rule for sowing, applied to trees, could be tested and confirmed for the first time.
A confirmation was also made known shortly after, through an independent
experiment using the same methodology with (among others) Sclerocarya birrea
(Bagnoud, 1995; Figure 1B).
The timing of sowing shortly before full and new Moon was shown to be rel-
evant: in an additional experiment sowing exactly at full Moon even worse results
were obtained than shortly before new Moon (Zürcher, 1992).
3.5. T
REE TIDES
An interdisciplinary reworking of previously published, long-term tree-
physiological research results has enabled to take the investigation a step further:
the synodic Moon-rhythm at a daily level (gravimetric tide-rhythm) could be
established for trees held under constant conditions (darkness). The already-
known, 24-hour photo- and thermoperiodic modulation of most physiological
processes is therefore embedded in a lunar-periodic, 24.8-hour rhythm which
appears when light and temperature as pacemakers are shielded off (Zürcher et al.,
1998) (Figure 2).
470 ERNST ZÜRCHER
Figure 1. (A) Mean height of Maesopsis eminii at 4 months after the sowing date (Zürcher, 1992).
(B) Mean height of Sclerocarya birrea at 2 months after the sowing date (Bagnoud, 1995). 1/3/5/ etc.:
Sowings 2 days before Full Moon; 2/4/6/ etc.: Sowings 2 days before New Moon.
LUNAR RHYTHMS IN FORESTRY TRADITIONS 471
Figure 2. Reversible diameter variations of two young Norway Spruce trees (Picea abies) under
controlled conditions (permanent darkness/(a) and gravimetric tides for the same period and location
(b) (Zürcher et al., 1998) (©Nature).
4. Research on the Correlation between Felling-Dates and Wood
Characteristics
4.1. D
RYING-BEHAVIOUR AND DENSITY
An overview on the most important studies with regard to the topic ‘felling-date’
(within the year-cycle) and wood- properties published so far gives an insight into
certain correlations between the biology and physics of wood (Gäumann, 1930;
Knuchel, 1930; Burmester, 1978). It becomes evident that a felling of trees in the
winter period is favourable for balanced drying-behaviour and optimal durability
of the wood. At that time of the year, the bre-saturation point (water absorption
through the cell-wall) is at its lowest. In his research, Knuchel paid special attention
472 ERNST ZÜRCHER
Figure 3. Dry density distribution of sapwood samples of Norway Spruce (Picea abies), for the
two groups of felling dates: before full Moon, in ascending period [u]/ before new Moon, in
descending period [g] (Rösch, 1999).
to the fact that the trees were felled during the same Moon-phase within the year
cycle, in order to deliberately exclude this factor. He thus left it to others to prove an
eventual influence of the Moon. Three investigations with regard to an implication
of the Moon phases on wood properties have recently been carried out. In one
of these studies initiated and supervised by the author of this text a total of
30 Norway-spruce trees originating from 6 felling-dates (3 during waxing Moon
and 3 during waning Moon) were divided into sample-series according to the 4
cardinal directions and investigated according to the drying/shrinkage behaviour
and oven-dry density in their final condition (Rösch, 1999). Standardized mater-
ial was taken from the sapwood (the still living, water-conducting outer part of
the stem) as well as from the heartwood (the inner, drier part of the stem). For
the entire sapwood samples after the two felling situations, from the relatively
homogeneous initial material, there resulted for instance the fact that the oven-
dry densities varied essentially: mean value ca. 0.46 g/cm
3
for the “unfavourable”
cases (at waxing Moon/towards full-Moon: “fm”) compared to ca. 0.51 g/cm
3
for
the “favourable” cases (towards new-Moon: “nm”) (Figure 3). For the heartwood
samples, the tendency shown is the same, although to a lesser extent.
The parallel observed between the felling-date-related values of sapwood and
heartwood comes to full effect thanks to the calculation of the relation between
the oven-dry density and the initial density (as “relative oven-dry density” in %),
thus small-scale, material-based initial variations are eliminated. For this criterium,
without exception, the nm-values are relatively higher than the adjacent fm-values,
especially for the fellings 3–6 (statistical analysis in Zürcher and Mandallaz, 2001;
Figure 4A).
LUNAR RHYTHMS IN FORESTRY TRADITIONS 473
Two similarly conceived investigations (Triebel, 1998 with 120 Norway-
spruce trees; Seeling and Herz, 1998 with 60 Norway-spruce trees) could
establish a statistically secured variation in the final oven-dry densities of the outer
sapwood samples in 2/3 of the cases, resp. in the entire trial. It is, therefore, in-
teresting that for December and January, all the new-Moon values for sapwood
are always significantly above the full-Moon values and correspond to the results
of Zurich (Figure 4B). To make the “lunar factor” evident, the seasonal trend can
be eliminated by comparing each of the values 2–5 (for relative density) with the
mean between the previous and the following value. Here again, the amplitude of
the systematic variations is obvious, as well as the similar, but weaker tendency for
the heartwood samples (Figure 4C).
4.2. C
OMPRESSION STRENGTH
For the determination of the compression strength at each of the four cardinal
directions in the sapwood and the heartwood, one each of the defect-free samples
(altogether 8 per tree) were investigated. A very close correlation with the value
distribution of kiln-drying densities for the sapwood as well as for the heartwood,
results. In both cases the systematic differences between fm- and nm-samples of
the fellings 3–6 are obvious. Sapwood as well as heartwood show the most sig-
nificant differences between felling date 4 (nm) and felling date 5 (fm): 17.8%
and 22.6% respectively. For the whole investigation, the nm-average value in
sapwood (47.2 N/mm
2
) surpasses the fm-average value (41.9 N/mm
2
) by 12.6%.
The heartwood’s nm-average value (40.7 N/mm
2
) surpasses the fm-average value
(36.6 N/mm
2
) by 11.2% (Figure 5).
These felling-date-related variations are astonishing at first sight for our cur-
rent knowledge of wood physics and ask for a formulation of further working
hypotheses.
5. Hypotheses
In view of the extremely weak gravitational forces, which came into question as an
explanation for circadian fluctuations, it is relatively unlikely that a direct gravita-
tional effect is responsible for these “tree and trunk tides”. One argument in support
of this view is the fact that other organisms, which move freely in all directions,
can also demonstrate such a “tide rhythm”. Behavioural scientists have established
in their famous “bunker experiment” that the basic physiological rhythm in people
allowed full freedom of movement whilst isolated from daily influences follows
not a 24-hour cycle but rather a 25-hour cycle (Aschoff and Wever, 1962). This
synodic daily rhythm could be connected to faint, constant variations of the Earth’s
magnetic field, possibly due to weak lunar influence. The detailed work Geomag-
netic Biology by Dubrov (1978), from the Soviet Academy of Science, offers more
474 ERNST ZÜRCHER
Figure 4. (A) Relative (oven-dry) density of sapwood and heartwood of Norway Spruce (Picea abies)
after 6 successive lunar-correlated felling dates in Zurich (sapwood: Plain line/heartwood: Dotted
line). (B) Systematic variation of oven-dry density after successive lunar-correlated felling dates in
3 sites and 3 years. Zurich 1998–1999: Plain line/Freiburg i.Br. 1997–1998: Dotted line1/Tharandt
1996–1997: Dotted line2. 1/3/5/7: Fellings before Full Moon; 2/4/6: Fellings before New Moon (after
Zürcher and Mandallaz, 2001; Seeling and Herz, 1998; Triebel, 1998). (C) Comparative relative
density of sapwood and heartwood samples from Zurich, with elimination of the seasonal trend
(based on values of 4A).
LUNAR RHYTHMS IN FORESTRY TRADITIONS 475
Figure 5. Systematic variation of compression strength of sapwood and heartwood of Norway Spruce
(Picea abies) after 6 successive lunar-correlated felling dates in Zurich. 1/3/5: fellings before Full
Moon; 2/4/6: fellings before New Moon (after Zürcher and Mandallaz, 2001).
information. Perhaps the Earth-atmospheric electric field also mentioned therein,
which varies periodically too, could play a role in chronobiological phenomena.
As far as the process which led to the diameter variations measured and to the
systematic variation in drying and shrinkage behaviour is concerned, two possible
explanations have so far been offered:
I. A process affecting membrane activity in living cells is occurring, which dir-
ects the movement of water into the cell wall and back out again into the
cytoplasm, coupled with water displacement via the apoplasts (cell wall system
outside the plasma membranes);
II. the process occurring is that of rhythmic variations in the wood-water relation-
ship (fixing of water in the cell wall). The relationship between the proportion
of free water and the proportion of chemophysically “fixed” water may, due
to the formation of variable supra-molecular organisational units, not be con-
stant. The work of G. Piccardi (Dubrov, 1978; Davis, 1995) focused on such
fluctuations in controlled crystallisation processes in laboratory experiments
covering a period of several years. E. Gäumann (1930), already concluded
from his detailed research that “the cause of the differing resistance to fungi
in spruce and fir woods lies less in a varying level of substances such as car-
bohydrate, nitrogen, phosphoric acid, potash and resin in the wood, but rather
in the differing colloid-chemical behaviour of the cell walls themselves, in
particular that of cellulose and xylan, to a lesser extent of lignin ...”.Forthis
author, such processes are not only confined to the sapwood, but also occur
in the heartwood. “With woods where the water content remains the same
year in, year out, for example as with spruce heartwood, the displacement of
476 ERNST ZÜRCHER
water must take place in a purely micellar way, perhaps in the sense that the
water molecules are stored in an intramicellar way during the formation of
the year ring, whilst being stored in an intermicellar way for the remainder of
the time”. (The crystalline cellulose chains of the microfibrils are considered
as micells, around which the hygroscopic paracrystalline cellulose is accumu-
lated.) Bavendamm (1974), too, takes the view, in his chapter regarding the
influence of the timing of felling on the durability of wood, that this is due
to varying colloid-chemical behaviour of cellulose and hemi-cellulose in the
different seasons of the year. This interpretation was later supported by the
work of Burmester (1978), according to which the moisture saturation point of
the fibres of the (normally considered as “dead”) oak heartwood significantly
varied over the course of the year (with one of the highest peaks occurring in
March).
6. Conclusion
There is so far a certain coherence between these scientific results and the
mentioned felling-date rules:
Lighter (‘full-Moon’-) wood is actually softer (with a lower compression
strength) than heavier (‘new-Moon’-) wood, the latter being more adequate
for construction.
Lighter wood could be somewhat more inflammable due to a higher water loss
and to a better passage of air than dense wood, and produce a better firewood
quality.
Furthermore, it is known that the natural durability in the comparison of species
increases tendentiously with density (Rijsdijk and Laming, 1994). Similarly,
Norway-spruce wood of the lowland regions grows much faster, is lighter and
is more easily attacked by fungi and rot than the wood of mountainous regions.
In this sense, dense “new-Moon-wood” could be more resistant to decay than
lighter “full-Moon-wood”.
Taking these rst available results into account, a specification of the felling-
date rules seems to be appropriate: felling should happen around the winter
solstice taking into account the synodic lunar rhythm, which in turn is then
synchronous with the tropical lunar rhythm (the alleged role of “zodiac signs”
has still to be critically tested).
It should also be mentioned that a “favourable” or “unfavourable” felling date for
wood in the absolute sense does not exist, but rather a more or less adequate relation
between properties and purpose of utilisation. There is “good” wood to be felled at
any date of the winter.
These examples provide us with various points of interest for further, practice-
oriented experiments in the eld of tree- and wood-related chronobiology. The
LUNAR RHYTHMS IN FORESTRY TRADITIONS 477
research results presented indicate a variety of possible benefits when put into
practice:
I. Chronobiological practice in tree nurseries would improve the criteria “eco-
nomy” and “quality”, with regard to future requirements (reforestation in
tropical regions with the aim of balancing CO2 levels);
II. the confirmed rhythmic variations of drying behaviour, density and mechan-
ical properties could lead to savings in energy and time during kiln-drying
processes, and to the formation of high-quality stocks of special woods; fur-
thermore, if linked with a higher durability, there is a potential of using less
wood protection chemicals;
III. it seems plausible that even weekly and daily timing criteria could lead to
specific wood properties.
It is in any case clear that the phenomena are much more complicated than is often
portrayed, and that they overstep many simplified traditional rules.
Without these strange reminders from past cultures we would, however, perhaps
never have conceived of these initial and further leading scientific observations in
this area.
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... This question is not new and has been debated for decades, yet with only limited success in resolution (Lüttge, 2003). In addition, would such tidal triggering help us in understanding the Moon-related traditional practices in forestry and agriculture that have been reported and used for so long across the continents (Zürcher, 2001)? Could such a gravitational Zeitgeber help our understanding of human physiological and behavioural rhythmicity (Erren et al., 2020)? ...
... Evidence exists that such a tidal-like synchronism does occur for di erent cyclic patterns, for example, for wood quality (Zürcher, 2001;Vogt et al., 2002), for the daily variation of tree trunk size (Zürcher et al., 1998;Barlow et al., 2010) and tree stem electrical potential (Barlow, 2012), for root growth Fisahn et al., 2012;Barlow et al., 2013), for chlorophyll uorescence (Fisahn et al., 2015), and for the ultra-weak photon emission (UPE) from seedlings (Moraes et al., 2012;Gallep et al., 2017). Here, revisiting existing data from well-documented studies, we also nd a tidal synchronism for the swimming activity of isopods kept in freerunning conditions (Enright, 1965), and for larvae release in a coral reef, recorded for 6 months after being in controlled, water-tide-free conditions for 16 months (Jokiel et al., 1985). ...
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... Sap flow has been studied as a rhythmic circadian and seasonal phenomenon especially in regard to the metabolism of plants, which is subject to external influences (Zürcher et al., 1998;Zürcher, 2001;Barbeta et al., 2012;Forster, 2014). Sap flow has been studied in many species including various oak subspecies (Ćermák et al., 1982;Granier et al., 1994;Barbeta et al., 2012). ...
... Thus tree xylem flow most probably is not the cause for the rhythmic form change observed. The rhythm of the tides, i.e., the moon's influence, has also been subject of some studies and would be worth looking at, especially since it has generated much controversial discussion (Zürcher et al., 1998;Vesala et al., 2000;Zürcher, 2001;Barlow et al., 2010). Causes of any detected rhythms in sap flow would demand a similar or even synchronous study of sap flow in the host tree and the mistletoe growing on it. ...
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... Moon's movement in an orbit around the earth affects the air currents on the earth, rise and fall of tides, and occurrence of thunderstorms [21]. For many years, farmers and craftsmen have carefully observed the moon phases while conducting certain forestry practices and planting, harvesting or collecting plants and rules are still being followed in accordance to the moon cycles [22]. There are evidences that near new moon, first quarter and after full moon (Super Moon) phases there is rise in the potassium contents of germinated seeds [23], correlations between magnetic variations and climate is more significant [24] and subjects who had slept with head in south direction for 12 weeks had lowest systolic blood pressure, diastolic blood pressure, heart rate and serum cortisol which was found to be statistically significant compared to other directions [25]. ...
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... Lunar rhythms are traditionally used by communities all over the world as a tool to assert the best germination and harvest time. This attention to the phase of the Moon is hailed to promote the best yield of the final product, including both quantity and quality of the harvested food or wood (Kollerstrom and Staudenmaier, 2001;Zürcher, 2001). ...
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... Müzik aleti, peynir kutuları, fıçı, tahta yalıtım maddeleri, baca, saban, pulluk vb. özel imalat gerektiren ürünler için kullanılacak odunun kesiminde ayın dönemlerine dikkat edilmesi gerektiğini bildirmektedir (Zürcher, 2001(Zürcher, ve 2011. Bunun nedenini; ağacın kesildiği zamana bağlı olarak su içeriği değiştiği için kuruma sürecinin değişmesine bağlamakta ve bu durumun da biyolojik etmenlerin arız olmasını etkilediğini belirtmektedir (Zürcher vd., 2010). ...
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The charcoal makers in Navarra, Spain place great store in the importance of pruning trees in the correct moon phase. According to them, beech trees should be cut in a waxing/growing moon. A small group of lapsed beech pollards were cut back close to the bolling in either a waxing (con luna) or waning (sin luna) moon. Growth responses of the trees were studied after four and six growing seasons. Significant differences were found between the growth of trees in each treatment with, for example, branches on sin luna trees producing more new shoots, more clusters of shoots, having longer new shoots on retained branches and more callus. However, a difference between trees in each treatment was also found, with sin luna trees having significantly larger cut branch diameters. Larger stub diameters also resulted in fewer new shoots, shorter new shoots and greater amounts of dieback which makes interpretation of the results difficult in relation to moon phase.
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Premechanized Mediterranean farmers exhibited considerable local and regional variability in tools and practices. Farmers also faced “real” choices, between alternatives with contrasting, but not determinant, costs and benefits. The costs and benefits of such alternatives were routinely understood and frequently acted upon, contrary to widespread dismissal of “traditional” Mediterranean farming as backward, with ignorance, superstition, and conservatism often highlighted as causes. The level of know-how of recent premechanized farmers differed little from that evident in Greco-Roman literary sources, which in turn drew on long oral and practical traditions of knowledge. Bronze Age and Neolithic practitioners perhaps had a poorer scientific understanding of farming than some Greco-Roman writers, but there is no reason to imagine that they had poorer powers of observation, pattern recognition, or decision-making than their classical and recent counterparts.
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The hypothesis, proposed by the late Gunter Klein, that the autonomous nyctinastic movements of bean leaves are related to the tidal force exerted by the Moon was tested. Using data collected by Dr. Klein, a close correspondence was found between the time at which leaves initiated a sudden downward turning movement and the time at which the tidal force changed from either a minimum ('low tide') or a maximum ('high tide'). In many cases the data sets of leaf movements and the changing tidal force gave evidence of correlative patterns of behavior. Evidence was also adduced for a minimal 6.2-h interval, or multiples thereof, between successively executed leaf movements. Data from an earlier study by A Kleinhoonte were also examined and have been found to show even closer correspondences than do Klein's data between bean leaf-movements and changing tidal forces. Thus, Klein's hypothesis of coherence between leaf and Moon is upheld.
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The diameter of tree stems growing under open and controlled conditions undergoes rhythmic fluctuations independent of daily periodic factors such as light, temperature and humidity. We find a strong correlation between these fluctuations and the timing and strength of tides. This correlation suggests that the Moon is influencing the flow of water between different parts of the trees.
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Zur Feststellung der natürlichen Dauerhaftigkeit des Kiefernholzes (Pinus sylvestris L.) wurden im Laufe eines Jahres Untersuchungen durchgeführt. Bohrkerne wurden in zweiwöchentlichen Abständen in genauer Übereinstimmung mit den Terminen des Neumondes und des Vollmondes entnommen. Sie wurden 12 Wochen lang der Einwirkung von Coniophora puteana, Stereum hirsutum und Chaetomium globosum in Reinkulturen ausgesetzt. Jahreszeitliche Änderungen der Dauerhaftigkeit wurden festgestellt: Sie ist in den Wintermonaten erhöht und verringert sich im Frühling. Einflüsse der Mondphasen auf die natürliche Dauerhaftigkeit des untersuchten Holzes ließen sich nicht feststellen. To determine the natural durability of pine wood (Pinus sylvestris L.) several investigations were carried out for all the seasons of a year. With fortnightly intervals drill cores were drawn in exact accordance with the new moon and full moon cycles. The specimens were subjected to the attack by Coniophora puteana, Stereum hirsutum and Chaetomium globosum in pure cultures for 12 weeks. Seasonal changes in durability were observed: it increases during the winter months and diminishes during spring. An influence of moon phases on the natural durability of the wood under investigation could not be ascertained.
Article
Basing on a model postulating that the biophysical power according to moon phase in connection with electrical-magnetical powers influence the vital functions of plants and animals positively or negatively, spruces were felled under same conditions during different moon phases. Than the following attacks of scolytid beetles were observed. These examinations were repeated over several years. For spruces of Waldviertel (Lower Austria) it could be proved that cutting the spruces in March and simultaneous begin of swarming after a cool period, the scolytidsIps typographus, I. amitinus andPityogenes chalcographus preferred full moon trees over new moon trees in distinct manner. This always happened in connection with biophysical fields. The same pictures showed spruces cutted in November, but the differences did not be so distinct. It can be concluded from these results, that organic substances later transformed to luring material are synthetisized in bigger extent to the time of full moon. Pheromones released from penetrated scolytides in the later course of swarming can alter the stated differences of attack at “full moon trees” and “new moon trees”. During summer trees from the former cutted series always showed more dangerous infestations by beetles than the later ones. Quick destruction and synthetisation of organic material through a warm period of 14 days did not let compare the original formed organic material to the time of the two moon-phases by different attacks of scolytid beetles. The results of these investigations are similar to some of common rules, connected with moon phases.
Untersuchungen zumBefallvonFichten-Fangbäumen durch Borkenkäfer imZusam-menhang mit Mondphasen zur Fällungszeit Untersuchungen über den Einfluss der Fällzeitauf dieEigenschaften des Fichten-und Tannenholzes, 1. Teil, Beiheft Nr
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Rhythmicities in the Germination and the Initial Growth of 4 Tree Species of the Soudano-Sahelian Zone. Moon Phase Trial
  • N Bagnoud