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

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

IUFRO Conference on uneven-aged silviculture June 17th-19th Structure of the classical plenter forest Equilibrium: V7 415m 3 G 44 m 2 Couvet section I/9 V7: 505 m 3 /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

IUFRO Conference on uneven-aged silviculture June 17th-19th 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 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 (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

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

IUFRO Conference on uneven-aged silviculture June 17th-19th (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

IUFRO Conference on uneven-aged silviculture June 17th-19th Fearce debates on the best system ( ) 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

IUFRO Conference on uneven-aged silviculture June 17th-19th Demographic equilibriumDBH Log N/ha Iteratively modelled assuming equilibrium between in-growth and out-growth (Schütz, 1975) Here experimental plot Rougemont (Guffre), Swiss Prealps, elevation: montain V 7 : 413 m 3 /ha; G: 31.5 m 2

IUFRO Conference on uneven-aged silviculture June 17th-19th Standing volume equilibrium Tree species V 7 (ha)G (ha)N 10 Couvet Joux Pélichet Höhronen Rougemont Schallenberg fir spru Artist’s woodDoug LangulaBeech

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

IUFRO Conference on uneven-aged silviculture June 17th-19th 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 CCF forms Group plentering Stem by stem plentering Mosaic cutting system Irregular group shelterwood

IUFRO Conference on uneven-aged silviculture June 17th-19th Application of plentering to other tree species Beech at Langula V7: 250m 3 G 21m 2 Douglas-Fir at Artist’swood Equilibrium at V7: 340m 3 G 27m 2

IUFRO Conference on uneven-aged silviculture June 17th-19th 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 

IUFRO Conference on uneven-aged silviculture June 17th-19th 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 The last step: full liberal silviculture

IUFRO Conference on uneven-aged silviculture June 17th-19th The End Thanks for your comprehension

IUFRO Conference on uneven-aged silviculture June 17th-19th Three dimensional structure triangle After Meyer, Recknagel, Stevenson, Bartoo (1961) Forest Management