Silviculture of oak for high-quality wood production

Oak is one of the most valuable noble hardwood species in Europe. The production of high-quality wood is associated with long rotations and high labour costs. The aim of this thesis was to quantify and model the effects of some silvicultural practices, mainly thinning, on crown size, volume growth and stem quality on pedunculate oak (Quercus robur L.), to provide a scientific basis to modify contemporary oak silviculture. The response pattern of specific silvicultural practices was tested in nine long-term thinning experiments and one operational stand located in Northern Europe. Results showed that pruning led to an overall increase in the total production of new epicormic shoots, which decreased with increasing height along the stem and with decreasing stand density. This suggests that early, heavy thinning combined with high pruning at regular intervals may help shorten the rotation length. A set of models for predicting crown radius was presented, based on different levels of predictor variables that offer flexibility in terms of data availability. The models can be used, for example, to calculate the average area potentially available for final crop trees and therefore the potential number of trees at the end of the rotation. Models for individual tree volume were fitted separately for predicting total and stem volume, whilst accounting for thinning practice. Results showed an increase in prediction accuracy in comparison to similar models available in the literature. Stand volume growth was analysed and modelled in relation to age, thinning practice and site. The highest growth was for unthinned stands, decreasing with increasing thinning grade. Volume growth of 50 potential future crop trees ha-1 increased with increasing thinning grade at all ages, demonstrating a positive effect of thinning on the growth of selected crop trees. The results lend support to the concept of crop tree silviculture based on early initiated, heavy thinning for the 'best' trees at regular intervals.

[1]  T. Wesol̸owski,et al.  Timing of bud burst and tree-leaf development in a multispecies temperate forest , 2006 .

[2]  P. Savill.  The Silviculture of Trees Used in British Forestry , 1991 .

[3]  F. Colin,et al.  Epicormic ontogeny on Quercus petraea trunks and thinning effects quantified with the epicormic composition , 2010, Annals of Forest Science.

[4]  Giulia Attocchi.  Effects of pruning and stand density on the productionof new epicormic shoots in young stands of pedunculate oak (Quercus robur L.) , 2013, Annals of Forest Science.

[5]  W. Ward.  Epicormic Branching of Black and White Oaks , 1966 .

[6]  P. Savill,et al.  Genetic determination of vessel area in oak (Quercus robur L and Q petraea Liebl): a characteristic related to the occurrence of stem shakes , 1993 .

[7]  N. Breda,et al.  Epicormic ontogeny in Quercus petraea constrains the highly plausible control of epicormic sprouting by water and carbohydrates. , 2012, Annals of botany.

[8]  P. Savill.  ANATOMICAL CHARACTERS IN THE WOOD OF OAK (j QUERCUS ROBUR L. AND Q.PETRAEA Liebl.) WHICH PREDISPOSE TREES TO SHAKE , 2017 .

[9]  J. P. Skovsgaard,et al.  Forest site productivity : A review of spatial and temporal variability in natural site conditions , 2013 .

[10]  E. Assmann,et al.  The Principles of Forest Yield Study: Studies in the Organic Production, Structure, Increment and Yield of Forest Stands , 2013 .

[11]  J. Dhôte,et al.  Forme de la tige, tarifs de cubage et ventilation de la production en volume chez le Chêne sessile , 2000 .

[12]  R. Harmer.  The Timing of Canopy and Epicormic shoot growth in Quercus robur L. , 1990 .

[13]  Jens Peter Skovsgaard,et al.  Erratum to: Biomass, basic density and biomass expansion factor functions for European beech (Fagus sylvatica L.) in Denmark , 2012, European Journal of Forest Research.

[14]  B. Ulrich,et al.  Temperate deciduous forests , 1992 .

[15]  J. Venet.  Pratique de la pré-désignation des arbres de place , 1968 .

[16]  W. R. Day.  THE OAK MILDEW MICROSPHAERA QUERCINA (SCHW.) BURRILL AND ARMILLARIA MELLEA (VAHL) QUEL. IN RELATION TO THE DYING BACK OF OAK , 1927 .

[17]  R. Harmer,et al.  Production of epicormic shoots on oak (Quercus robur): effects of frequency and time of pruning , 2001 .

[18]  M. Löf,et al.  Reforestation in southern Scandinavia using direct seeding of oak (Quercus robur L.) , 2005 .

[19]  J. P. Skovsgaard,et al.  Crown radius of pedunculate oak (Quercus robur L.) depending on stem size, stand density and site productivity , 2015 .

[20]  T. Zlatanov,et al.  Crown volume in forest stands of pedunculate oak and common hornbeam. , 2009 .

[21]  J. Gibbs,et al.  Biotic and abiotic factors affecting the dying back of pedunculate oak Quercus robur L. , 1997 .

[22]  U. Jönsson.  Phytophthora species and oak decline - can a weak competitor cause significant root damage in a nonsterilized acidic forest soil? , 2004 .

[23]  S. Kirk,et al.  Managing acute oak decline. , 2010 .

[24]  G. Hemery,et al.  Applications of the crown diameter–stem diameter relationship for different species of broadleaved trees , 2005 .

[25]  David J. Mabberley,et al.  The Plant-Book , 1987 .

[26]  G. E. Hemery,et al.  Forest Management and Silvicultural Responses to Projected Climate Change Impacts on European Broadleaved Trees and Forests , 2008 .

[27]  J. P. Skovsgaard,et al.  Recreational preferences depending on thinning practice in young even-aged stands of pedunculate oak (Quercus robur L.): comparing the opinions of forest and landscape experts and the general population of Denmark , 2013 .

[28]  Vivian Kvist Johannsen,et al.  Compatible stem taper and stem volume functions for oak (Quercus robur L and Q petraea (Matt) Liebl) in Denmark , 1997 .

[29]  F. Thomas,et al.  Abiotic and biotic factors and their interactions as causes of oak decline in Central Europe , 2002 .

[30]  T. Cech,et al.  The impact of invasive Phytophthora species on European forests. , 2013 .

[31]  D. Mabberley.  The Plant Book , 1988 .

[32]  C. Moroşanu,et al.  The influence of oak raw timber defects on decorative veneer cutting. , 2011 .

[33]  Fabrice Bonne,et al.  Stem Growth and Epicormic Branch Formation in Understorey Beech Trees (Fagus sylvatica L.) , 2001 .

[34]  P. Brang,et al.  Growth and quality of young oaks (Quercus robur and Quercus petraea) grown in cluster plantings in central Europe: A weighted meta-analysis , 2012 .

[35]  S. Fink.  SOME CASES OF DELAYED OR INDUCED DEVELOPMENT OF AXILLARY BUDS FROM PERSISTING DETACHED MERISTEMS IN CONIFERS , 1984 .

[36]  E. Hochbichler.  Methods of oak silviculture in Austria , 1993 .

[37]  J. P. Skovsgaard,et al.  Precommercial thinning of pedunculate oak: Recreational preferences of the population of Denmark for different thinning practices in young stands , 2009 .

[38]  H. Polge.  Production de Chênes de qualité en France , 1984 .

[39]  H. Kwaśna.  Fungi in the rhizosphere of common oak and its stumps and their possible effect on infection by Armillaria , 2001 .

[40]  F. Colin,et al.  Initial spacing has little influence on transient epicormic shoots in a 20-year-old sessile oak plantation , 2008, Annals of Forest Science.

[41]  J. Krahl-Urban.  Die Eichen : Forstliche Monographie der Traubeneiche und der Stieleiche , 1959 .

[42]  J. Timbal,et al.  An overview of ecology and silviculture of indigenous oaks in France. , 1996 .

[43]  R. Lorne.  Etude quantitative sur les éclaircies dans les peuplement de chêne de qualité , 1959 .

[44]  L. Roussel.  Lumière, gourmands et rejets de souches , 1978 .

[45]  T. Jung,et al.  Involvement of soilborne Phytophthora species in Central European oak decline and the effect of site factors on the disease , 2000 .

[46]  P. Savill,et al.  Short note : genetic control of oak shake; some preliminary results , 1991 .

[47]  T. Wignall,et al.  The Effects of Stand Thinning and Artificial Shading on Epicormic Bud Emergence in Pedunculate Oak (Quercus robur L.) , 1988 .

[48]  Hubert Hasenauer,et al.  A crown ratio model for Austrian forests , 1996 .

[49]  P. Savill,et al.  Tree improvement programs for European oaks: goals and strategies , 1993 .

[50]  G. Kerr.  The effect of heavy or ‘free growth’ thinning on oak (Quercus petraea and Q. robur) , 1996 .

[51]  Koji Shimano.  Analysis of the relationship between DBH and crown projection area using a new model , 2006, Journal of Forest Research.

[52]  J. Webber,et al.  Oak declines: new definitions and new episodes in Britain. , 2009 .

[53]  F. Colin,et al.  Evolution of the epicormic potential on 17-year-old Quercus petraea trees: first results , 2001 .

[54]  H. Spiecker,et al.  Silviculture of high-quality oaks: questions and future research needs , 1993 .

[55]  B. Beinhofer.  Comparing the financial performance of traditionally managed beech and oak stands with roomy established and pruned stands , 2010, European Journal of Forest Research.

[56]  A. Barbati,et al.  Climate change impacts, adaptive capacity, and vulnerability of European forest ecosystems , 2010 .

[57]  G. Hemery,et al.  The New Sylva: A Discourse of Forest and Orchard Trees for the Twenty-First Century , 2014 .

[58]  G. Peterken,et al.  Silviculture of Broadleaved Woodland. , 1984 .

[59]  J. Satchell.  Resistance in oak (Quercus spp.) to defoliation by Tortrix viridana L. in Roudsea Wood National Nature Reserve , 1962 .

[60]  J. S. Jensen.  Provenance Variation in Phenotypic Traits in Quercus robur and Quercus petraea in Danish Provenance Trials , 2000 .

[61]  C. Fleming,et al.  Taxonomy: Species status of hybridizing oaks , 2000, Nature.

[62]  Oscar García,et al.  Evaluating forest Growth Models , 1997 .

[63]  M. R. Saunders,et al.  Epicormic buds in trees: a review of bud establishment, development and dormancy release. , 2012, Tree physiology.

[64]  Henrik Meilby,et al.  Site-specific height growth models for six common tree species in Denmark , 2009 .

[65]  E. Assmann.  Waldertragskunde : organische Produktion, Struktur, Zuwachs und Ertrag von Waldbeständen , 1961 .

[66]  Joan Webber,et al.  A description of the symptoms of Acute Oak Decline in Britain and a comparative review on causes of similar disorders on oak in Europe , 2014 .

[67]  R. Mosandl,et al.  Rationelle Pflege junger Eichenbestände , 2002 .

[68]  F. Colin,et al.  Observation of Quercus petraea epicormics with X-ray CT reveals strong pith-to-bark correlations: Silvicultural and ecological implications , 2012 .

[69]  J. Pajares,et al.  Geometrid outbreak waves travel across Europe. , 2013, The Journal of animal ecology.