Transcript IUFRO Zürich 2014

Can knowledge on plentering be
used to generate a general concept
of forest heterogeneity?
Jean-Philippe Schütz
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Outline
• The plenter system an old empiric way of
practicing sustainable forest use
• The check method a liberation from
mechanistic forestry
• Extension to every tree species
• Free cutting use a way to a fully free
silviculture
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Structure of the classical plenter forest
Couvet section I/9
V7: 505 m3/ha
• The plenter forest
treatment issued
from an old use of
family patrimony
• Maintaining the
farm
• Only the cadet
herit
• Economic value of
large timber
Equilibrium: V7
415m3
G 44 m2
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Floating on the Rhine river
Floating was the best way to haul
timber down to the Dutch
shipyhards
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Geography of the classic plenter forests
• The plenter forest
treatment only in
montainous
regions
• 500‘000 ha
• But a very singular
system
• An other way of
achieving forestry
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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The check-method controversy
• 1860-1880 (F) Gurnaud tentative
of freeing forest management
from clear cutting system
• Check method (Méthode du
contrôle)
• Paradigmatic idea: the real
observed increment should
determine the yield regulation
• Application lead step by stem to
the optimum (experimental
treatment)
A. Gurnaud
1825-1898
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Implementation of the check method
Controle as a method of follow
up the stand developpement
Experimental treatment
Yield shouldn’t be decreted but
constated
Henri Biolley
1858 - 1939
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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The continuous forest controversy
• 1823 (G) Möller idea of
continuous forestry
• Forest as (ecosystem) an
organism
• Continuity of renewal without
generational change
• Favour mixtures
A. Möller
1860-1923
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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The plenter forest controversy
• Fearce debates on the best system (1920-1960)
• Plentering against all others systems with
superficic renewal
• Is plenter forest appliable to every tree
species, particularly intolerant ones and
broadleaved ones ?
• A lot of scientific study: on optimal standing
volume and conditions of maintaining the
system sustainable (recruitment)
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Demographic equilibrium
Log N/ha
1,000.0
100.0
Iteratively modelled
assuming equilibrium
between in-growth and
out-growth
(Schütz, 1975)
10.0
1.0
0.1
10 18 26 34 42 50 58 66 74 82 90
DBH
Here experimental plot
Rougemont (Guffre), Swiss
Prealps, elevation: montain
V7: 413 m3/ha; G: 31.5 m2
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Standing volume equilibrium
Tree
species
V7 (ha) G (ha)
N10
Couvet
Joux Pélichet
Höhronen
Rougemont
Schallenberg
fir spru
414
422
529
393
482
35
38
41
32
41
115
111
134
143
184
Artist’s wood
Doug.
413
32
198
Langula
Beech
253
21
94
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Different form of acheiving irregularity
• Is stem by stem the only way ?
• From a point of view of regeneration
ecology the small gap is better
• A combination between shelterwood and
gaps is one more efficient
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Regeneration of intolerant species in gaps
Intolerant species (Oak) in too
small gaps:
- not styable at edge
- Heliotopic deformation
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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CCF forms
Stem by stem plentering
Group plentering
Mosaic cutting system
Irregular group shelterwood
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Application of plentering to other tree species
Douglas-Fir at Artist’swood
Equilibrium at V7: 340m3
Beech at Langula
V7: 250m3 G
21m2
G 27m2
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Enlarging the concept to all tree species
The plenter principles (1946)
• Utilisation of individual growth
potential
• Every harvest is nurturing
operation
• Continuity of the regeneration
• Free choice of cutting
H. Leibundgut
The free style of silvicultrure 
Dušan Mlinsek
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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The last step: full liberal silviculture
• Using intentionally all cutting form
• Adapted to site and tree species
• Wide range of variation
• But decentral in time and space
This is the best way to promove forest
diversity as habitat
Therefore the best contribution to enhance
biodiversity
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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The End
Thanks for your
comprehension
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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Three dimensional structure triangle
Trajectory of a
plantation in
transformation
Plenter
equilibrium
0
20
40
60
80
small timber
La Joux Pélichet
100
After Meyer, Recknagel,
Stevenson, Bartoo
(1961)
Forest Management
Equilibrium
IUFRO Conference on uneven-aged silviculture June 17th-19th 2014
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