Skip header and navigation

21 records – page 1 of 3.

Conseils pour réussir une plantation de peupliers hybrides

https://library.fpinnovations.ca/en/permalink/fpipub8506
Author
Zhang, Tony
Chauret, Gilles
Duchesne, Isabel
Schneider, Robert
Date
2006
Material Type
Pamphlet
Field
Fibre Supply
Author
Zhang, Tony
Chauret, Gilles
Duchesne, Isabel
Schneider, Robert
Date
2006
Material Type
Pamphlet
Physical Description
4 p.
Sector
Forest Operations
Field
Fibre Supply
Research Area
Forestry
Subject
Partial cutting
Coupe partielle
Series Number
OT-02
Language
French
Abstract
Two cubic meters of wood from different stems are not the same in terms of value and quality of the wood value and quality of the wood because the characteristics of a stem have a great influence on the value and the value and quality of the products that can be obtained from it. They also influence the costs of harvesting and harvesting and processing costs per cubic meter of wood.
Abstract
Deux mètres cubes de bois provenant de tiges différentes ne se ressemblent pas en termes de valeur et de qualité du bois car les caractéristiques d’une tige influent énormément sur la valeur et la qualité des produits que l’on peut en tirer. Elles influencent aussi les coûts de récolte et de transformation par mètre cube de bois.
Documents
Less detail

Maximizing the value of jack pine resource

https://library.fpinnovations.ca/en/permalink/fpipub5985
Author
Zhang, S.Y. (Tony)
Chauret, Gilles
Duchesne, I.
Schneider, R.
Date
August 2005
Edition
42322
Material Type
Research report
Field
Sustainable Construction
Author
Zhang, S.Y. (Tony)
Chauret, Gilles
Duchesne, I.
Schneider, R.
Date
August 2005
Edition
42322
Material Type
Research report
Physical Description
161 p.
Sector
Wood Products
Field
Sustainable Construction
Research Area
Advanced Wood Materials
Subject
Value added
Thinning
Stands
Pinus banksiana
Pinus
Growth
Series Number
General Revenue Project No. 2403
E-3970
Location
Sainte-Foy, Québec
Language
English
Abstract
Initial spacing This study examined the impact of initial spacing on tree characteristics, product quality and value recovery in jack pine. The study was based on one of the oldest initial spacing trials established in 1941 in Wellston, Michigan. In 2001, trees were collected from each tree DBH class in 3 initial spacings, 5x5 (1.52mx1.52m), 7x7 (2.13mx2.13m) and 9x9 (2.74mx2.74m). Trees were also collected from blocks that had been spaced (PCT) from 5x5 to 7x7 at age 13. The following were measured for each sample tree: crown width and length, total tree height, tree height up to 7.5cm top, tree height up to 9.1cm top (10cm DBH class) and average diameter of the 5 largest branches. Based on these measurements, stem volume, stem taper and length of the log below live crown were calculated. Each stem was then scanned in a log scanner for determining the impact of optimized bucking and sawing on lumber recovery using sawmilling simulation software. Stems were bucked into 8-foot long logs with a 4-inch overlength (2.54 m) according to sawmill practice. A 5-cm thick disk was collected from the base of each stem and from the top of each 8-foot sawlog for wood quality determinations. Lumber conversion was carried out in 4 separate batches so that chip samples could be collected for determining chip and pulp quality. Each piece of lumber was visually graded both before and after kiln drying. A static bending test was also performed to determine lumber strength and stiffness. Based on the sample trees, the impact of initial spacing and the PCT treatment was evaluated at the DBH class level and at the stand level. Finally, a benefit/cost analysis was made for the 4 treatments. Wood and pulp properties and sawing simulations will be reported separately. Increasing initial spacing in jack pine from 5x5 to 7x7 had a considerable impact on average tree diameter (+14%) and volume (+30%) 57 years after planting. However, when spacing was further increased to 9x9 the additional gains in tree diameter (4%) and volume (3%) were considerably more modest. On the other hand, the PCT treatment in the 5x5 spacing in which stand density was decreased from approximately 4300 trees/ha to 2200 trees/ha, increased tree DBH by 6.6% and tree volume by 18%. The negative impact of increasing initial spacing and PCT treatment on branch size and tree taper follows a similar trend. Average branch diameter in 5x5, 7x7 and 9x9 spacing was 30.1, 35.1 and 37.0mm respectively and 32.8mm in the thinned 5x5 stand. Average tree taper also increased considerably as spacing was increased from 5x5 (0.64cm/m) to 7x7 (0.79cm/m), the increase was much less as spacing was further increased to 9x9 (0.86cm/m). Average nominal lumber volume recovery also increased considerably with increasing initial spacing. Once again the increase was more pronounced in narrow to moderate spacing than from moderate to wide spacing. On the other hand, lumber grade recovery did not decrease with increasing initial spacing in this study, as suggested by the increase in branch and knot size. In fact the highest yield of SS grade was in lumber from the 9x9 spacing, and its yield of SS & No. 1 lumber, is only marginally lower than that of lumber from the narrow 5x5 spacing. This is largely due to the fact that rot was also a major cause of downgrade in all stand densities and its impact was somewhat less important in the widest spacing. The presence of rot alone was responsible for 24.7% (9x9) to 56.9% (5x5) of lumber downgrade to No. 3 and Economy, which has a direct and significant impact on lumber value. Lumber strength and stiffness decreased with increasing initial spacing. The modulus of elasticity (MOE) and modulus of rupture (MOR) of lumber from the widest spacing are 7.4% lower than those of lumber from the narrowest 5x5 spacing. But, the MOR of lumber from moderate (7x7) spacing is only approximately 3% higher than that of lumber from wide spacing (9x9). MOE and MOR of lumber from the thinned and unthinned 5x5 spacing are very similar which indicates that the PCT treatment did not seriously affect bending properties. In addition, the mechanical properties of those 2 stands compare well with those of lumber from young 50-year old natural stand. Generally, MOE and MOR decreased from butt log to top log in all spacings. An economic analysis was carried out for a 47 and 57-year rotation using tree and lumber data that were generated for each tree DBH class in the 2001 study, as the initial spacing trial was 60-years old. The economic analysis was carried out in the context of sustainable forestry through intensive silviculture, which assumes that trees are planted each year at the same initial spacing. And for each year of operation, return on investment or benefit to cost ratio is estimated using current product values and costs. The analyses indicate that benefit to cost ratios increase with increasing initial spacing both at 47 and 57-year rotations. However, none of the stand densities generated any profit at 47-year rotation mainly due to high harvesting and processing costs. It is nevertheless estimated that the widest initial spacing (9x9) would have shown a positive economic return on investment (B/C 0.96 in this analysis) had lumber values been based on 47-year old stems rather than 60-year old stems, since lumber downgrade due to rot would have been lower. In addition, improvements in lumber processing would also have a positive impact on stand value and profit. But, in order to be profitable on short rotations, plantations should be established in regions that are particularly favourable to jack pine growth. In the 57-year rotation only the narrow 5x5spacing failed to generate profit (Benefit/cost 0.87). The economic impact of a precommercial thinning treatment in the dense 5x5 stand appears to be modest. However, in plantation-grown jack pine and especially in stands such as the one in the present study where tree form is a major problem, PCT treatments should be primarily aimed at eliminating deformed stems to have maximum impact on tree and stand value. It appears that this stand should have been harvested before age 60 since there was high mortality in the last 10 years and essentially no additional volume growth. In fact, the only positive growth that was recorded from age 47 to 57, was in the 9x9 spacing with 8.6m3/ha over the 10-year period. Precommercial thinning This study examined the impact of precommercial thinning (PCT) intensity on tree characteristics, product quality and value recovery in jack pine. The study was based on one of the oldest precommercial thinning trials established in 1966 on a poorly drained sandy-silty loam by the New Brunswick Department of Natural Resources and Energy. The trees on this site originated from fire in 1941. In 2000, 6 trees were collected from each commercial tree DBH class in 3 thinning intensities, 4x4 (1.22mx1.22m), 5x5 (1.52mx1.52m), 7x7 (2.13mx2.13m) and a control stand, for a total of 154 trees. The following were measured for each sample tree: crown width and length, total tree height, tree height up to a 7-cm top, tree height up to 9.1-cm top (10-cm DBH class) and average diameter of the 5 largest branches. Based on these measurements, stem volume, stem taper and length of the log below live crown were calculated. Before bucking, the shape and size of each stem was determined using a laser transit and a target board overlaid with high precision graph paper. These virtual stems will be used to determine the impact of optimized processing on product volume and value recovery using a sawmilling simulation software developed by Forintek (Optitek). Stems were bucked into 8-foot long logs according to sawmill practice. A 5-cm thick disk was collected from the base of each stem and from the top of each 8-foot sawlog for wood quality determinations. Lumber conversion was carried out in 4 separate batches so that chip samples could be collected for determining chip and pulp quality. Each piece of lumber was visually graded both before and after kiln drying. A static bending test was also performed to determine lumber strength and stiffness. Based on the sample trees, the impact of PCT intensity was evaluated at the DBH class level and at the stand level. Finally, a benefit/cost analysis was made for the 4 treatments. Wood and pulp properties and sawing simulations will be reported separately. Since jack pine is a shade-intolerant species mortality decreased with increasing PCT intensity, as expected. Mortality in the 7x7, 5x5 and 4x4 thinning was 16.7, 20.6 and 24.2% respectively, and 29.6% in the control stand. The impact of mild (thinned to 4x4) and moderate (thinned to 5x5) PCT treatment on tree growth was relatively modest 34 years after treatment. However, when thinning intensity is further increased to 7x7 (2200 stems/ha) the gains are considerable. Tree diameter increases by over 20%, from 15.1cm in the control stand to 18.3cm in the stand thinned to 7x7. Average tree height increases from 14.5m to 16.4m (13.1%) and merchantable stem volume per tree increases by more than 75%, from 105.1dm3 to 185.5dm3. Total log volume recovery and green lumber volume recovery per tree is respectively 67% and 59% higher in trees from intensive thinning than in trees from the control stand. Lumber volume recovery per cubic meter of stem is slightly higher in trees from the 7x7 thinning than in trees from the control stand, and as a result wood consumption in the intensive thinning is somewhat lower. On the other hand, trees from the 5x5 thinning and control stand generally have similar log and lumber volume recoveries, which are higher than those from the 4x4 thinning. Lumber quality generally increases with increasing thinning intensity. Yields of visually graded No. 2 and better lumber are 87.7%, 86.0% and 77.5% in stands thinned to 7x7, 5x5 and 4x4 respectively, and 79.2% in lumber from the control stand. The presence of large knots is the main downgrading defect in jack pine lumber from intensively thinned stands where it is responsible for 27.4% of the downgrade, while wane is responsible for approximately 25 to 30% of the downgrade in lumber from the control and mild thinning stand. Lumber and total product value recoveries per tree are approximately 70% higher in trees from intensive thinning than in control trees. And lumber value per thousand feet board, and per cubic meter of stem, are 14% higher in trees from intensive thinning. Once again trees from control and moderate thinning (5x5) have similar product value recoveries and these are superior to those of trees from mild thinning. The economic analysis indicates that return on investment increases with increasing thinning intensity. Benefit to cost ratios, are 1.26, 1.31 and 1.46 for stands thinned to 4x4, 5x5 and 7x7 respectively. However, the unthinned control stand has a higher benefit to cost ratio (1.33) than stands from mild and moderate thinning. It thus appears that stand density has to be reduced to approximately 2200 stems/hectare (7x7) to be economically viable. On the other hand, strength and stiffness properties of lumber decrease with increasing thinning intensity. The modulus of rupture (MOR) in stands thinned to 4x4, 5x5 and 7x7 is respectively, 57.2, 55.3 and 46.9 MPa, and the modulus of elasticity (MOE) is 11 242, 10 927 and 9823 MPa. MOR and MOE in lumber from the control stand are 51.9 MPa and 10 219 MPa, which is respectively 10.6% and 4.0% higher than those of lumber from intensive thinning. While bending properties of lumber from intensive thinning are the lowest in this study, they are nevertheless comparable to those of lumber from natural stands of good to excellent growth, as demonstrated in a recent study in 50, 73 and 90-year old jack pine stands from Northern Ontario. Lumber strength and stiffness also decrease fairly drastically from the butt log to the top log in all stands. In summary, the results from this study indicate that mild and moderate thinning treatments do not have sufficient impact on tree and stand volume and value recoveries to generate a positive return on investment. A fairly intensive PCT treatment is thus required to be economically viable. It also appears that strength and stiffness properties of lumber from intensively thinned stands will be similar to those of lumber from natural stands of similar rotation age. Commercial thinning The impact of commercial thinning of jack pine stands on growth, yield and financial variables was examined. Data from 5 treated stands spread through Eastern Canada was used to calibrate individual tree and stand level models. Individual trees showed a good response to thinning, with the larger stems having the best reaction to thinning. Larger stems, however, could not take full advantage of the heavy thinning. At stand level, thinning had little effect on merchantable volume. Sawlog volume (merchantable volume of the stems with a diameter at breast height of 15.1 cm and more) showed a strong response to thinning, with heavy thinning having more sawlog volume. Thinning reduces the income of a stand, but reduces even more the cost to harvest and saw the stand. The return on investment and net present value (NPV) favour heavily thinned stands, with moderately thinned stands having the same NPV, but higher return on investment. Impact of rotation age This study examined the impact of rotation age on tree and wood characteristics, lumber quality and value recovery in natural jack pine forests. The study was based on three stands all established after forest fires in the region of Timmins, Ontario. These stands were 50, 73 and 90 years old. In 2002, a total of 142 sample trees were collected. For each stand, 6 trees per DBH class were selected to cover all diameter classes (DBH) in 2-cm interval. For each sample tree, major tree characteristics were measured: total tree height, tree height up to 9.1 cm diameter top (10 cm DBH class); DBH and stem diameter from the stump to the top at 1-m interval; live crown width and length and average diameter of the 5 largest branches. Based on these measurements, other tree characteristics were calculated: stem volume, stem taper, and length of the log without live crown. Each sample tree was bucked to 8-foot-long logs for lumber conversion. From the top of each log, a 3-cm-thick disc was removed for the evaluation of wood characteristics. Lumber conversion was carried out in a way which allows to keep track of the provenance of each piece of lumber. Logs from each stand were processed separately so that chip samples could be collected. Each piece of lumber was visually graded after drying and planing. Bending tests were performed to determine the mechanical properties (bending strength and stiffness) of the lumber pieces. Based on the sample trees, the impact of rotation age was evaluated first at the diameter class level and then at the stand level. Finally, a cost/benefit analysis was made for the three rotation ages. For the three stands analyzed, tree height, tree diameter, tree volume, branch diameter and taper increased with diameter class (which is an effect of age). Basic density (90 yr-old stand data only) decreased from butt log to top log for all diameter classes. Since the quality of the natural jack pine stands was excellent, the Economy grade accounted only for 2.4% or less of the total lumber volume production for each stand in this study. In the 90-yr-old stand, decay caused 20.6% of the downgrades, whereas for the 73- and 50-yr-old stands, downgrades due to decay was low or inexistent (5.2% and 0% respectively). When grades No. 2 and better were combined (current market practice), no significant differences were found among the three rotation ages. The present study clearly shows that rotation age influences lumber quality. The 50-yr-old stand had a significantly lower lumber strength (MOR, 42 MPa) about 16% below that of the 73- and 90-yr-old stands (48 and 49 MPa). This can be partly explained by a higher proportion of juvenile (immature) wood at an age of 50 years. The lumber stiffness (MOE) at age 50 was also significantly lower (19 and 16%, 9441 MPa) compared to the 73- and 90-yr-old stands (11234 and 10927 MPa respectively). From the lumber strength and stiffness point of view, the 50-yr-old stand can be considered too young for harvest. The two older stands were similar in terms of lumber mechanical properties, which were very good (i.e. met or exceeded the mean-based MOE design values of the grade, unlike the 50-yr-old stand). For the three rotation ages, MOR and MOE decreases from the butt log to top log. The benefits/cost analysis indicates that it is economically more profitable to harvest natural jack pine stands at an age of 90 years. However, regarding stand productivity, the 90-yr-old stand showed the lowest annual stand volume increment of 3.21 m3/ha/year, compared to 5.25 and 3.82 for the 50- and 73-yr-old stands, respectively. The stand also showed the highest mortality (loss of fibres) and rate of lumber downgrades due to decay. From the view point of lumber properties, downgrades due to decay and tree mortality, a moderate rotation age of about 70 years is preferred in jack pine.
Pinus banksiana - Growth
Thinning
Stand value
Documents
Less detail

Knowledge transfer : maximizing jack pine value

https://library.fpinnovations.ca/en/permalink/fpipub5987
Author
Zhang, S.Y. (Tony)
Chauret, Gilles
Duchesne, I.
Schneider, R.
Date
January 2005
Edition
42358
Material Type
Pamphlet
Field
Sustainable Construction
Author
Zhang, S.Y. (Tony)
Chauret, Gilles
Duchesne, I.
Schneider, R.
Date
January 2005
Edition
42358
Material Type
Pamphlet
Physical Description
4 p.
Sector
Wood Products
Field
Sustainable Construction
Research Area
Advanced Wood Materials
Subject
Silviculture
Wood quality
Series Number
Fact Sheet
E-4053
Location
Sainte-Foy, Québec
Language
English
Abstract
.
Silviculture
Wood quality
Forest products - Quality
Documents
Less detail

Impact of initial spacing on tree and wood characteristics, product quality and value recovery in black spruce (Picea mariana)

https://library.fpinnovations.ca/en/permalink/fpipub42023
Author
Zhang, S.Y. (Tony)
Chauret, Gilles
Date
March 2001
Material Type
Research report
Field
Sustainable Construction
Author
Zhang, S.Y. (Tony)
Chauret, Gilles
Contributor
Canada. Canadian Forest Service
Date
March 2001
Material Type
Research report
Physical Description
47 p.
Sector
Wood Products
Field
Sustainable Construction
Research Area
Advanced Wood Materials
Subject
Wood
Value added
Pinus
Spruce
Spacing
Recovery
Quality control
Qualitative analysis
Picea
Black spruce
Series Number
Canadian Forest Service No. 35
E-3527
Location
Sainte-Foy, Québec
Language
English
Abstract
This study examined the impact of initial spacing on various tree and wood characteristics, product quality and value recovery in black spruce. The study was based on the oldest initial spacing trial established in 1950 near Thunder Bay, Ontario. In 1998, all the trees in the trial were measured and sample trees were collected from 4 different spacings (3086, 2500, 2066, 1372 trees/ha). For each spacing, 6 trees per DBH class were selected to cover all DBH classes in 2-cm interval. For each sample tree, major tree characteristics were measured: 1) total tree height, tree height up to 5 cm diameter top, tree height up to 9.01 cm diameter top (10cm DBH class), 2) DBH and stem diameter from the stump to the top at 1-m interval, 3) live crown width and length, and 4) average diameter of the 5 largest branches. Based on these measurements, other tree characteristics were calculated: 1) stem volume, 2) stem taper, and 3) length of the log without live crown. Each sample tree was bucked to 8-foot-long logs for lumber conversion. From the top of each log, a 5-cm-thick disc was removed for the evaluation of wood characteristics. Lumber conversion was carried out in a way which allows to keep track of the provenance of each piece of lumber. Logs from each spacing were processed separately so that chip samples could be collected for the evaluation of chip quality and pulping properties. Each piece of lumber was visually graded both before and after drying. In-grading tests were also performed to determine lumber strength and stiffness. Based on the sample trees, impact of initial spacing was evaluated first at the diameter class level and then at the stand level. Finally, a cost/benefit analysis was made for the 4 spacings. In addition, special attention was paid on the impact of initial spacing on lumber strength and stiffness. Mechanical properties of plantation-grown black spruce lumber were also compared to those of black spruce from natural forest. Initial spacing in black spruce has a considerable effect on diameter growth of individual trees. It appears that tree diameter increases moderately when stand density decreases from 3086 to 2066 trees/ha. However, when stand density decreases further to 1372 trees, tree diameter increases considerably. With decreasing stand density, average live crown size and branch diameter of the black spruce plantations show a steady increase, and consequently the best grade (Select Structural) recovery tends to decrease. However, when grades No.2 and Better are combined (current market practice), no significant differences were observed among the 4 initial spacings. With decreasing stand density, average stem taper for trees of the same diameter class tends to increase. As a result, trees of the same diameter class from lower stand density generally tend to have a lower tree volume, and thus a lower lumber volume and value recovery per tree. On the other hand, lumber volume/value recovery per tree increases dramatically with tree diameter. Consequently, at the stand level, the lowest stand density still have a considerably higher lumber volume/value recovery per tree due to an increased average tree diameter. Despite the fact that trees in the lowest stand density are larger, the total stand (product) value per hectare is lower than in the case of the denser stand (3086 trees/ha) because it has fewer trees. However, the lowest stand density (1372 trees/ha) generates a better economic return than the highest stand density because of the lower initial investment and reduced harvesting and processing costs per m3 of resource. Lumber from stand densities of 3086, 2500 and 2066 trees/ha has a comparable strength and stiffness. However, lumber strength and stiffness from stand density of 1372 trees/ha are respectively about 30 and 18% lower on average, than the other 3 stand densities. The major source of concern arises when the 48-year-old plantations are compared to the black spruce from natural stands being processed across eastern Canada. On average, lumber stiffness from the natural stands is about 60% higher than the average lumber stiffness of trees from plantation-grown trees of initial stand density of 1372 trees/ha. Results also indicate that lumber stiffness generally increases with increasing log height in the tree. However, lumber strength does not follow the same trend. In general, it appears that lumber strength decreases from the butt log until it reaches its lowest point and then tends to increase steadily with height. While we are confident that the results of the impact of initial spacing on tree/wood characteristics and product recovery and value at the tree DBH class level reflect the general trend for this species within these initial stand densities. We believe that the trends at the stand level reported in this study may not necessarily apply to other sites because the tree diameter frequency distributions for different spacings and growing conditions may vary, which will affect the overall economic return. Therefore, it is necessary to apply the economic variables (costs and values) obtained at the tree level to data from more sites across eastern Canada before a recommendation on optimal initial spacing could be made for black spruce.
Initial spacing
Wood characteristics
Quality
Value recovery
Black spruce
Picea mariana
Documents
Less detail

Érable à sucre taché : essais préliminaires

https://library.fpinnovations.ca/en/permalink/fpipub5947
Author
Chauret, Gilles
Giroux, Y.
Date
October 1999
Edition
41886
Material Type
Research report
Field
Sustainable Construction
Author
Chauret, Gilles
Giroux, Y.
Date
October 1999
Edition
41886
Material Type
Research report
Physical Description
14 p.
Sector
Wood Products
Field
Sustainable Construction
Research Area
Advanced Wood Materials
Subject
Sapstain
Series Number
E-3300
Location
Sainte-Foy, Québec
Language
French
Abstract
Sapstain
Sugar maple
Documents
Less detail

Caractéristiques et utilisation du bois des clones de peupliers hybrides

https://library.fpinnovations.ca/en/permalink/fpipub5041
Author
Chauret, Gilles
Koubaa, Ahmed
Zhang, S.Y. (Tony)
Date
April 1999
Edition
41885
Material Type
Research report
Field
Sustainable Construction
Author
Chauret, Gilles
Koubaa, Ahmed
Zhang, S.Y. (Tony)
Date
April 1999
Edition
41885
Material Type
Research report
Physical Description
53 p.
Sector
Wood Products
Field
Sustainable Construction
Research Area
Advanced Wood Materials
Subject
Wood structure
Wood
Populus
Hybrid
Series Number
E-3299
Location
Sainte-Foy, Québec
Language
French
Abstract
Hybrid poplar - Wood structure
Documents
Less detail

Impact of precommercial thinning on tree and wood characteristics, and product quality and value in balsam fir

https://library.fpinnovations.ca/en/permalink/fpipub41855
Author
Zhang, S.Y. (Tony)
Corneau, Yvon C.
Chauret, Gilles
Date
August 1998
Material Type
Research report
Field
Sustainable Construction
Author
Zhang, S.Y. (Tony)
Corneau, Yvon C.
Chauret, Gilles
Date
August 1998
Material Type
Research report
Physical Description
65 p.
Sector
Wood Products
Field
Sustainable Construction
Research Area
Advanced Wood Materials
Subject
Wood
Thinning
Quality control
Qualitative analysis
Balsam
Series Number
Canadian Forest Service No 39
E-3159
Location
Sainte-Foy, Québec
Language
English
Abstract
Cette étude a examiné l'impact de l'éclaircie précommerciale de sapin baumier sur différentes caractéristiques du bois et des arbres, ainsi que sur la qualité et la valeur des produits. Cette étude était basée sur le plus ancien site d'éclaircie précommerciale établi par le Ministère des Ressources naturelles du Québec situé près d'Amqui, dans la région du bas St-Laurent. Le peuplement a été regénéré suite à une coupe à blanc en 1948. En 1960, alors que le peuplement était agé de 12 ans, plusieurs parcelles d'éclaircies et parcelles témoins ont été établies afin d'obtenir plusieurs densités résiduelles différentes. En 1995, 35 ans après l'éclaircie précommerciale, 150 arbres d'intérêt commerciale ont été sélectionnés afin de représenter toutes les classes de diamètre (intervalle de 2 cm) d'arbres qui se retrouvaient dans la parcelle témoin et dans les parcelles éclaircies d'intnsité modérée et intensive. À partir de ces arbres échantillons, l'impact de l'éclaircie précommerciale sur différentes caractéristiques du bois et des arbres, ainsi que sur la qualité et la valeur des produits, a été évalué pour chacune des classes de diamètre. Les paramètres étudiés incluaient le diamètre, la hauteur, le défilement et le volume de l'arbre, la longueur et la largeur de la cime, la longueur de la bille sans branches vivantes (sous la cime), le diamètre des branches, l'épaisseur de l'écorce, la densité du bois, le contenu en bois de coeur, la teneur en humidité, le rendement en volume des billes, le rendement en volume des sciages, le rendement en classes de qualité des sciages, le rendement en dimensions des sciages, le rendement en valeu des sciages, la rigidité et la résistance mécanique des sciages, le volume et la valeur des copeaux et le rendement total en valeur. Le mesurage de toutes les parcelles en 1985 et 1995 a aussi permis de déterminer l'effet de l'éclaircie précommerciale apès 25 ans et 35 ans, sur un certain nombre de paramètres ( la surface terrière, le diamètre moyen des arbres, le volume marchand et la valeur des produits) au niveau des peuplements. Selon ces résultats, des intensités d'éclaircie ont été recommandées pour différentes industries. D'autres aspects important ont également été abordés. En comparaison avec les arbres témoins, les arbres d'intérêt commercial des parcelles éclaircies d'une même classe de diamètre ont une hauteur sensiblement moindre, un plus grand défilement et un volume plus faible. Par conséquence, ces arbres ont un rendement en volume de billes et de sciage plus faible. Il en va de même pour le volume de copeaux produit par arbre. Quelque différences ont aussi été remarquées entre les arbres éclaircis et témoins de même classe de diamètre, en ce qui conceerne les caractéristiques qui peuvent affecter la qualité. En génral, les arbres d'intérêt commercial des parcelles éclaircies ont des cimes plus loongues et plus larges, des billes sous la cime plus courtes et de plus grosses branches (diamètre) que les arbres provenant des parcelles témoin. En conséquence, les sciages d'une même classe de diamètre d'arbres provenan des parcelles éclaircies ont un plus faible rendement pour la meilleure classe de qualité (Structure choisie). Par contre, aucune différence significative a été notée par le rendement par les classes de qualité #2 et Meilleur combinées. De plus, cette étude démontre qu'une éclaircie d'intensité modérée a un effet limité sur la qualité des sciages. En fait, les sciages de la même classe de diamètre d'arbres, des parcelles témoin et d'éclaircie modérée ont presque le même rendement qualité. Ils ont également un module d'élasticité (MOE) et un module de rupture (MOR) comparable. Cependant, les arbres provenant des parcelles d'éclaircie intensive ont un MOE et un MOR sensiblement plus faible, spécialement dans le cas des plus grosses classes de diamètre. Ces diminutions du MOE et MOR sont principalement dues à un plus grand diamètre des branches (noeuds) et à une diminution de la densité du bois. Par ailleurs, les arbres d'intérêt commercial des parcelles témoin ont un rendement en valeur (total des produits) par arbre, légèrement plus élevé que ceux d'une même classe de diamètre provenant des parcelles éclaircies. Ceci est principalement dû au fai qu'ils ont un rendement en volume de sciages légèrement plus élevé. Par contre, les caractéristiques du bois et des arbres ainsi que la qualité et la valeur des produits, varient remarquablement avec le diamètre de l'arbre. La hauteur et le volume de l'arbre augmentent considrablement avec le diamètre. Ceci a pour résultat d'augmenter significativement le rendement en volume de sciages, le rendement en volume de copeaux et le rendement en dimensions des sciages par arbre, etceci, autant pour les arbres de la parcelle témoin que pour ceux des parcelles éclaircies. La largeur de la cime, le pourcentage de cime, le diamètre des branches, l'épaisseur de l'écorce, le défilement et le taux d'humidité augmentent de façon variable également avec un accroissement du diamètre. La longeur de la bille sous la cime et le contenu en bois de coeur (en terme d'age) ne semblent pas cepandant changer de façon appréciable avec le diamètre. Cependant, la densité du bois tend à diminuer avec l'accroissement du diamètre, spécialement dans les parcelles intensément éclaircies. En ce qui concerne la qualité des sciages, le rendement en meilleure classe de qualité pour les arbres des parcelles intensément éclaircies diminue considérablement avec une augmentation du diamètre, ce qui n'est pas le cas pour les arbresdes parcelles témoins. De même, le MOE et MOR des arbres des parcelles d'éclaircie intensive diminue considérablement avec un acroissement du diamètre et de façon moindre dans le cas des arbres des parcelles d'éclaircie modérée. Cette tendance ne se rencontre pas dans les parcelles témoins. Lavaleur totale des produits par arbres, augmente d'une façon considérable avec le diamètre de l'arbre, grâce à l'augmentation du rendement en volume de sciage et de copeaux et aussi à cause dde la dimension des sciages. Par exemple, un arbre de 28 cm vaut $ 28,73, ce qui équivaut à 13.1 arbres de 10 cm au dhp. Cette étude démontre que l'éclaircie précommerciale peut accélérer la croissance radiale de l'arbre, mais qu'une intensité d'éclaircie ne laissant pas plus de 3,500 arbres/ha (tous les arbres) après traitement, est requise pour obtenir un gain substantiel du diamètre des arbres. Plus l'éclaircie est inrensive, plus les gains sont significatifs en terme de diamètre. De plus, l'éclaircie précommerciale dans les peuplements denses de sapin baumier augmente le volume de bois commercial et la valeur des produits au niveau du peuplement. Avec une diminution de la densité du peuplement (ou une augmentation de l'intensité d'éclaircie) de 7500 arbres/ha à 1000 arbres/ha (tous les arbres), le volume du bois commercial augmente graduellement jusqu'à un maximum, puis tend à diminuer. En 1985, soit 25 ans après le traitement, le plus important volume de bois commercial (12.8m³/ha) correspond à une densité de peuplement de 2500-3000 arbres/ha (tous les arbres) ou 1500-2000 arbres/ha (arbre, plus de 1cm), mais l'intensité d'éclaircie de 1000-2000 arbres/ha (tous les arbres) ou 500-1200 arbres (plus d'un cm) produit la plus haute valeur (produits) de peuplement. En 1995, 35 ans après l'éclaircie précommerciale, la plus grande valeur de peuplement de 2500-3000 arbres/ha (tous les arbres) ou 1500-2000 arbres/ha (plus d'un cm). Il faut cependant noter que la valeur des peuplements d'intensité d'éclaircie de 1000-3500 arbres/ha (tous les arbres) varie peu, mais que les éclaircie qui laissent plus de 3500 arbres/ha produiront des peuplements de valeur nettement inférieure. En fait, les parcelles non-éclaircies de plus de 7500 arbres/ha (tous les arbres) pourraient valoir jusqu'à 2000$/ha de mmooins en valeur des produits. Cette étude suggère que l'éclaircie précommerciale des peuplements très denses de sapin baumier semble être un traitement sylvicole efficace et viable. Elle démontre également que l'éclaircie précommerciale peut réduire l'âge d'exploitabilité jusqu'à 10 ans. Ceci est particulièrement intéressant pour les scieries qui pourraient faire face à une pénuries de billes de sciage dans le futur. Une réduction de l'âge de récolte réduira l'apparition de pourriture et de carie dans les peuplements de sapin baumier. De plus, un diamètre plus grand des arbres dans les peuplements éclaircis réduira leds coûts de récolte et de transformation et produira des sciages de plus grandes dimensions. En plus des avantages économiques, les avantages sociaux et environnementaux ont aussi été touchés brièvement dans ce rapport. Il faudrait retenir que l'éclaircie précommerciale peut cependant avoir quelques effets négatifs sur la qualité des billles (i.e.,défilement, diamètre des branches, longueur des billes sous la cime) et conséquemment sur la qualité du produit. Les effets négatifs pourraient toutefois être réduits par la sélction d'une intensité d'éclaircie appropriée et de l'âge de l'intervention. Selon la réponse de certain paramètre-clés (i.e., diamètre de l'arbre, qualité et valeur du produit) au niveau du peuplement, 25 ans et 35 ans après l'éclaircie précommerciale, des recommandations ont été faites pour différentes industries (tableau 31). Puisque la valeur des peuplements qui ont été soumis à une éclaircie précommerciale variant entre 1000-3500 arbres/ha varie très peu, il s'ensuit que la décision du choix de l'intensité d'éclaircie dépend en grande partie des objectifs de la compagnie en cause (tableau 30). SI une compgnie désire maximiser la croissance en diamètre et/ou réduire l'âge d'exploitabilité, une éclaircie intensive devrait être choisie. Si par contre, une compagnie veut mettre l'accent sur la qualité des produits l'intensité de l'éclaircie devrait être plutôt modérée.
Precommercial Thinning
Wood characteristics
Product Quality
Balsam Fir
Documents
Less detail

Industrial bark utilization : perspectives for major eastern Canadian softwoods

https://library.fpinnovations.ca/en/permalink/fpipub41715
Author
Zhang, S.Y. (Tony)
Chauret, Gilles
Date
January 1995
Material Type
Research report
Field
Sustainable Construction
Author
Zhang, S.Y. (Tony)
Chauret, Gilles
Date
January 1995
Material Type
Research report
Physical Description
3 p.
Sector
Wood Products
Field
Sustainable Construction
Research Area
Advanced Wood Materials
Subject
Utilization
Softwoods
Canada
Bark
Location
Sainte-Foy, Québec
Language
English
Abstract
Bark - Utilization
Softwoods - Eastern Canada
Documents
Less detail

Impact of stand characteristics on product value in eastern spruce/fir stands

https://library.fpinnovations.ca/en/permalink/fpipub38659
Author
Corneau, Yvon C.
Chauret, Gilles
Date
June 1993
Material Type
Research report
Field
Sustainable Construction
Author
Corneau, Yvon C.
Chauret, Gilles
Date
June 1993
Material Type
Research report
Physical Description
17 p.
Sector
Wood Products
Field
Sustainable Construction
Research Area
Advanced Wood Materials
Subject
Yield
Value added
Pinus
Spruce
Series Number
Forestry Canada No. 38
3712K218
E-1897
Location
Ottawa, Ontario
Language
English
Abstract
The objective to this study was to process a matched sample of tree lengths harvested from a mature and an overmature site in order to quantify to lumber volume, lumber quality and lumber value of each tree sample.
Forests and Forestry
Spruce
Fir
Yield - Value
Documents
Less detail

The causes and occurence of warp in eastern spruce-pine-fir dimension lumber

https://library.fpinnovations.ca/en/permalink/fpipub1959
Author
Barbour, R.J.
Chauret, Gilles
Date
March 1993
Edition
38484
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Barbour, R.J.
Chauret, Gilles
Date
March 1993
Edition
38484
Material Type
Research report
Physical Description
28 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Pinus
Spruce
Spruce Pine Fir
SPF
Series Number
Forestry Canada No. 37
3712K209
E-1403
Location
Ottawa, Ontario
Language
English
Abstract
Eastern SPF producters experience an average value loss of $10 to $16/mbf due to drying degrade. A clear understanding of how wood characteristics influence warp will make it easier to effectively modify drying processes to reduce these losses. The goal of this study was to categorize green lumber according to its potential to warp, dry the lumber using a typical industrial kiln schedule and assess whether pieces that either warped or remained straight were correctly identified. Experimental material was a sample of 440 black spruce 8-foot 2x4's from four grain defect groups. These were : 1) control, no grain defects; 2) cross grain but no compression wood; 3) compression wood but no cross grain; and 4) both cross grain and compression wood. Methods used to select lumber with either a high or low potential to warp were successful. Warp was found to be related to the severity of compression wood and cross grain in each piece. Lumber without cross grain or compression wood dried with very little warp. Lumber with both cross grain and compression wood had the lowest quality after drying.
Spruce-Pine-Fir - Warp
SPF Lumber
Documents
Less detail

21 records – page 1 of 3.