Can knowledge on plentering be used to generate a general concept of forest heterogeneity?...

1

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

IUFRO Conference on uneven-aged silviculture June 17th-19th 2014 2

• 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

Outline


Structure of the classical plenter forest

Equilibrium: V7 415m3

G 44 m2

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


Floating on the Rhine river

Floating was the best way to haul timber down to the Dutch shipyhards


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


• 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)

The check-method controversy

A. Gurnaud 1825-1898


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


• 1823 (G) Möller idea of continuous forestry

• Forest as (ecosystem) an organism

• Continuity of renewal without generational change

• Favour mixtures

The continuous forest controversy

A. Möller 1860-1923


• 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)

The plenter forest controversy


Demographic equilibrium

10

14

18

22

26

30

34

38

42

46

50

54

58

62

66

70

74

78

82

86

90

94

0.1

1.0

10.0

100.0

1,000.0

DBH

Log N/haIteratively modelled assuming equilibrium between in-growth and out-growth

(Schütz, 1975)

Here experimental plot Rougemont (Guffre), Swiss Prealps, elevation: montain

V7: 413 m3/ha; G: 31.5 m2


Standing volume equilibrium

Tree species

V7 (ha) G (ha) N10

CouvetJoux PélichetHöhronenRougemontSchallenberg

fir spru 414422529393482

3538413241

115111134143184

Artist’s wood Doug. 413 32 198

Langula Beech 253 21 94


• 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

Different form of acheiving irregularity


Regeneration of intolerant species in gaps

Intolerant species (Oak) in too small gaps:

- not styable at edge

- Heliotopic deformation


CCF forms

Group plentering

Stem by stem plentering Mosaic cutting system

Irregular group shelterwood


Application of plentering to other tree species

Beech at Langula V7: 250m3 G 21m2

Douglas-Fir at Artist’swood Equilibrium at V7: 340m3

G 27m2


The plenter principles (1946)• Utilisation of individual growth

potential• Every harvest is nurturing

operation• Continuity of the regeneration• Free choice of cutting

Enlarging the concept to all tree species

H. Leibundgut

Dušan Mlinsek

The free style of silvicultrure


• Using intentionally all cutting form• Adapted to site and tree species• Wide range of variation• But decentral in time and spaceThis is the best way to promove forest

diversity as habitatTherefore the best contribution to enhance

biodiversity

The last step: full liberal silviculture


The End

Thanks for your comprehension


Three dimensional structure triangle

0 10 20 30 40 50 60 70 80 90 100

La Joux Pélichet Equilibrium

90

8

0

7

0

6

0

5

0

4

0

3

0

2

0

10

medium

timber

small timber

larg

e tim

ber

90 80 70 60 50 40 30 20

10

Plenter equilibrium

Trajectory of a plantation in transformation

After Meyer, Recknagel, Stevenson, Bartoo (1961) Forest Management

Can knowledge on plentering be used to generate a general concept of forest heterogeneity?...

Documents

Transcript of Can knowledge on plentering be used to generate a general concept of forest heterogeneity?...