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Effects of thinning practice, high pruning and slash management on crop tree and stand growth in young even-aged stands of planted silver birch (Betula pendula Roth) / Jens Peter Skovsgaard in Forests, vol 12 n° 2 (February 2021)
[article]
Titre : Effects of thinning practice, high pruning and slash management on crop tree and stand growth in young even-aged stands of planted silver birch (Betula pendula Roth) Type de document : Article/Communication Auteurs : Jens Peter Skovsgaard, Auteur ; Ulf Johansson, Auteur ; Emma Hölmstrom, Auteur ; Rebecka McCarthy Tune, Auteur ; Clémentine Ols , Auteur ; Giulia Attocchi, Auteur Année de publication : 2021 Projets : ARBRE / AgroParisTech (2007 -), LUE / Université de Lorraine Article en page(s) : n° 225 Note générale : bibliographie
This work was supported by the Swedish forest-owner association Södra and the Swedish national research program Future Forests. C. Ols was funded by the French National Research Agency (ANR-11-LABX-0002-01 and ANR-15-IDEX-04-LUE) during her review and editing of the paper.Langues : Anglais (eng) Descripteur : [Termes IGN] Betula pendula
[Termes IGN] Canada
[Termes IGN] croissance des arbres
[Termes IGN] éclaircie (sylviculture)
[Termes IGN] élagage (sylviculture)
[Termes IGN] étude d'impact
[Termes IGN] forêt équienne
[Termes IGN] Suède
[Termes IGN] volume en bois
[Vedettes matières IGN] SylvicultureRésumé : (auteur) The objective was to quantify the influence of thinning, high pruning and slash management on crop tree and stand growth in young even-aged stands of planted silver birch (Betula pendula Roth). This study was based on two field experiments, aged six and eleven years at initiation and re-measured after six and eight years, respectively. Treatments included the unthinned control, moderate thinning mainly from below (removing 28–33% of standing volume), point thinning to favor 300 trees per ha and with no thinning elsewhere in the plot (removing 16–25%), and heavy thinning leaving 600 evenly distributed potential future crop trees per ha (removing 64–75%). Slash management (extraction or retention) was applied to heavily thinned plots. High pruning removing 30–70% of the green crown was carried out in some plots with point or heavy thinning on 300 or 600 trees per ha, respectively. Stand volume growth increased with increasing pre-treatment mean annual volume increment and decreased with increasing thinning intensity as compared to the unthinned control. LS-means estimates indicated a reduction for moderate thinning by 14%, for point thinning by 12% and for heavy thinning (combined with pruning) by 62%. However, in the youngest experiment, heavy thinning (without pruning) reduced growth by 54%. Combining these results with results from a similar experiment in Canada, the reduction in stand volume growth (RedIv%) depending on thinning removal (RemV%), both expressed as a percentage of the unthinned control, was quantified as RedIv% = −23.67 + 1.16·RemV% (calibration range: 30–83%). For heavy thinning (large quantities of slash), slash extraction resulted in no reduction in stand volume growth as compared to slash retention. The instantaneous numeric reduction in the average stem diameter of the 300 thickest trees per ha (D300) due to thinning was 3.5, 15–21% and 955–11% with moderate, point and heavy thinning, respectively. The subsequent average annual increase in D300 during the observation period was 8.5%, 25 and 18%, respectively. In the youngest experiment, pruning in unthinned plots led to a reduction in the annual increase of D300 by 14%, and heavy thinning in unpruned plots led to an increase by 30%. The growth of pre-selected potential future crop trees increased with increasing thinning intensity. In heavily thinned plots, pruning reduced growth increasingly with increasing pruning severity; LS-means estimates indicated 21% larger growth on stem diameter for unpruned trees and 3% for pruned trees. As an adverse side effect, heavily thinned plots with only 600 trees per ha were at increased risk of windthrow for some years after the thinning intervention. In the oldest experiment, 95–21% of the trees in these plots were damaged by wind. Numéro de notice : A2021-171 Affiliation des auteurs : LIF+Ext (2020- ) Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/f12020225 Date de publication en ligne : 16/02/2021 En ligne : https://doi.org/10.3390/f12020225 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97132
in Forests > vol 12 n° 2 (February 2021) . - n° 225[article]Use of non-destructive test methods on Irish hardwood standing trees and small-diameter round timber for prediction of mechanical properties / Daniel F. Llana in Annals of Forest Science, vol 77 n° 3 (September 2020)
[article]
Titre : Use of non-destructive test methods on Irish hardwood standing trees and small-diameter round timber for prediction of mechanical properties Type de document : Article/Communication Auteurs : Daniel F. Llana, Auteur ; Ian Short, Auteur ; Annette M. Harte, Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Acer pseudoplatanus
[Termes IGN] acoustique
[Termes IGN] Betula pendula
[Termes IGN] betula pubescens
[Termes IGN] bois sur pied
[Termes IGN] densité du bois
[Termes IGN] diamètre des arbres
[Termes IGN] éclaircie (sylviculture)
[Termes IGN] élagage (sylviculture)
[Termes IGN] élasticité
[Termes IGN] feuillu
[Termes IGN] Fraxinus (genre)
[Termes IGN] Fraxinus excelsior
[Termes IGN] Irlande
[Termes IGN] modèle de simulation
[Termes IGN] résonance
[Termes IGN] vent
[Vedettes matières IGN] SylvicultureRésumé : (auteur) Key message: Mechanical properties of small-diameter round timber from hardwood thinnings of common alder ( Alnus glutinosa (L.) Gaertn.), European ash ( Fraxinus excelsior L.), European birch ( Betula pendula Roth. and Betula pubescens Ehrh.), and sycamore ( Acer pseudoplatanus L.) can be evaluated by non-destructive testing on either standing trees or green logs without wood density determination. Velocity differences between acoustic and resonance methods are influenced by tree species and age. Tree diameter improves the estimation of bending strength but not of stiffness.
Context: There is a need for a reliable, fast, and inexpensive evaluation method to better sort hardwood thinnings according to mechanical properties for use in potential added-value applications.
Aims: The estimation by non-destructive testing of mechanical properties of round small-diameter timber of four hardwood species (common alder, European ash, European birch, and sycamore).
Methods: Acoustic velocity was measured in 38 standing trees and resonance velocity was recorded in green logs from these trees. The logs were then dried and tested in bending. Estimation models to predict mechanical properties from non-destructive testing measurements were developed.
Results: Large differences between velocities from acoustic and resonance techniques were found. Models based on both non-destructive testing velocities together with a species factor are well correlated with bending modulus of elasticity while models including tree diameter are moderately well correlated with bending strength. Inclusion of density in the models does not improve the estimation.
Conclusion: Models based on acoustic measurements on standing trees or resonance on green logs together with tree species and diameter provide reliable estimates of mechanical properties of round timber from hardwood thinnings. This methodology can be easily used for pre-sorting material in the forest.Numéro de notice : A2020-403 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-020-00957-x Date de publication en ligne : 17/06/2020 En ligne : https://doi.org/10.1007/s13595-020-00957-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95453
in Annals of Forest Science > vol 77 n° 3 (September 2020)[article]High-pruning of silver birch (Betula pendula Roth): work efficiency as a function of pruning method, pole saw type, slash removal, operator, pruning height and branch characteristics / Jens Peter Skovsgaard in International Journal of Forest Engineering, vol 29 n° 2 ([15/05/2018])
[article]
Titre : High-pruning of silver birch (Betula pendula Roth): work efficiency as a function of pruning method, pole saw type, slash removal, operator, pruning height and branch characteristics Type de document : Article/Communication Auteurs : Jens Peter Skovsgaard, Auteur ; Clémentine Ols , Auteur ; Rebecka Mc Carthy, Auteur Année de publication : 2018 Projets : 1-Pas de projet / Université de Lorraine Article en page(s) : pp 117 - 127 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Betula pendula
[Termes IGN] élagage (sylviculture)
[Vedettes matières IGN] SylvicultureRésumé : (auteur) The objective of this study was to establish an operational model of work efficiency (net or productive work time per tree) for high-pruning of young silver birch depending on pruning method, pole saw type, operator, pruning height and branch characteristics. The final model included number of branches, cross-sectional area of the thickest branch at the cut, pruning height, pruning method (target or flush pruning) and operator as independent variables. Work time increased with increasing values of each of the three numeric variables. For a given pruning height the number of branches was for all practical purposes more influential than the size of the largest branch. Target pruning was significantly faster than flush pruning, all else being equal. The variation in work efficiency for the five operators in the study spanned a range almost twice as large as that attributed to pruning method. The mean work time for other activities during the pruning operation (supportive work time) was estimated at 17% of the productive work time for pruning. Numéro de notice : A2018-019 Affiliation des auteurs : LIF+Ext (2012-2019) Autre URL associée : vers HAL Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/14942119.2018.1462593 Date de publication en ligne : 15/05/2018 En ligne : https://doi.org/10.1080/14942119.2018.1462593 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93826
in International Journal of Forest Engineering > vol 29 n° 2 [15/05/2018] . - pp 117 - 127[article]Manipulating tree crown structure to promote old-growth characteristics in second-growth redwood forest canopies / Stephen C. Sillett in Forest ecology and management, vol 417 (15 May 2018)
[article]
Titre : Manipulating tree crown structure to promote old-growth characteristics in second-growth redwood forest canopies Type de document : Article/Communication Auteurs : Stephen C. Sillett, Auteur ; Marie E. Antoine, Auteur ; Jim Campbell-Spickler, Auteur ; Allyson L. Carroll, Auteur ; Ethan J. Coonen, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 77 - 89 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation
[Termes IGN] Californie (Etats-Unis)
[Termes IGN] canopée
[Termes IGN] croissance des arbres
[Termes IGN] élagage (sylviculture)
[Termes IGN] houppier
[Termes IGN] Sequoia sempervirensRésumé : (Auteur) In old-growth Sequoia sempervirens forests, reiterated trunks and limbs provide required habitat elements for specialized arboreal species, including an endangered seabird, Brachyramphus marmoratus. The oldest second-growth redwood forests—established after 19th century logging—lack species dependent on complex structure, presumably because redwoods maintain simple, model-conforming crowns for centuries unless damaged by wind or fire. We imposed a factorial experiment on 24 redwoods 59–75 m tall in six second-growth forests to determine if trunk reiteration and limb formation can be induced by removing treetops (topping) and branch tips (tipping) to disrupt apical control. We also increased light availability in the upper crown by pruning branches. After intensively mapping trunks and branches and imposing treatments, we re-mapped trees three years later to quantify growth increments. Topping stimulated trunk reiteration from the cut, and reiterated tops gained height more rapidly than controls. Tipping also stimulated trunk reiteration from branches, especially when combined with topping, resulting in formation of limbs (i.e., branches giving rise to reiterated trunks). Pruning had consistently negative effects on trunk and branch growth increments even after accounting for post-treatment variation in leaf area and light availability, suggesting that photosynthate was diverted to compartmentalization of wounds. Strategic injury of trees may have long-term conservation value in second-growth redwood forests if limbs can be initiated high enough in the crown to persist as trees approach maximum height. Topping and tipping treatments should be combined with silvicultural thinning of neighboring trees to increase light availability far more than can be achieved by pruning. Numéro de notice : A2018-469 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.foreco.2018.02.036 Date de publication en ligne : 08/03/2018 En ligne : https://doi.org/10.1016/j.foreco.2018.02.036 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91150
in Forest ecology and management > vol 417 (15 May 2018) . - pp 77 - 89[article]Effect of first thinning type and age on growth, stem quality and financial performance of a Scots pine stand in Finland / Pentti Niemistö in Silva fennica, vol 52 n° 2 ([01/05/2018])
[article]
Titre : Effect of first thinning type and age on growth, stem quality and financial performance of a Scots pine stand in Finland Type de document : Article/Communication Auteurs : Pentti Niemistö, Auteur ; Harri Kilpeläinen, Auteur ; Eero Poutiainen, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] croissance des arbres
[Termes IGN] déboisement
[Termes IGN] éclaircie (sylviculture)
[Termes IGN] élagage (sylviculture)
[Termes IGN] Finlande
[Termes IGN] modèle de croissance végétale
[Termes IGN] peuplement forestier
[Termes IGN] Pinus sylvestris
[Termes IGN] qualité du bois
[Vedettes matières IGN] SylvicultureRésumé : (Auteur) The objective of the study was to ascertain the effects of tree selection (thinning from below, from above and according to stem quality) and timing of first commercial thinning (early and delayed) on the growth, yield and quality of trees in a Scots pine (Pinus sylvestris L.) stand. A long-term field experiment (25 years) was measured in 5-year periods and the further development was simulated with growth and yield models to final cuttings using alternative rotation periods of 55–85 years. The measurements included also the exact location and type of technical defects detected on all trees in the experimental plots. The measured volume increment per unit area during the study period, 25 years after the early thinning stage was the lowest in the plots thinned from below, and the highest in the plots thinned from above or in the delayed thinning plots. However, the largest volume of saw logs during the whole rotation of 80 years was yielded after early first thinning according to the quality. The largest volume of very high-quality butt logs was produced by pruning connected with early thinning from above, and a smaller volume after early thinning according to stem quality but no after thinning from below or delayed first thinning. Without pruning an early quality thinning with one intermediate thinning was the most profitable thinning treatment in the Scots pine stand regardless the rotation length or the interest rate used. By interest rates of 1% and 2%, the optimal rotations were 80–85 years and 70 years respectively. A late thinning at the age of 60 year with long rotation was profitable only for the pruned pine stands with a low interest rate. Numéro de notice : A2018-500 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.14214/sf.7816 Date de publication en ligne : 14/02/2018 En ligne : https://doi.org/10.14214/sf.7816 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91188
in Silva fennica > vol 52 n° 2 [01/05/2018][article]La sylviculture selon Georges Gautier / Vincent Motin in Le Bois International : l'officiel du bois [édition verte], vol 2008 n° 37 (1er novembre 2008)Permalink