Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: Part 4 – Lumber production, quality and value

2013 ◽  
Vol 89 (04) ◽  
pp. 474-489 ◽  
Author(s):  
Isabelle Duchesne ◽  
Doug G. Pitt ◽  
Francis Tanguay
Keyword(s):  
Value Chain ◽  
Positive Impact ◽  
Abies Balsamea ◽  
Basic Density ◽  
Production Quality ◽  
Balsam Fir ◽  
Appreciable Effect ◽  
Precommercial Thinning ◽  
Product Value ◽  
Negative Effect

Forty-eight years after application, three nominal precommercial thinning (PCT) spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate, balsam fir (Abies balsamea [L.] Mill.)-dominated stands. Within three of these replicates chosen for clearcut harvest in 2008, a total of 150 trees were bucked into 479 sawlogs that produced 10 829 board feet of lumber. PCT had a positive impact on Premium lumber grade recovery per tree, increasing it from an average of 9 foot board measure (fbm) in the unthinned control plots, to 22 fbm in plots nominally spaced to 8 ft (p = 0.02). No. 2 & Better grade yields increased from 42 to 76 fbm/tree in these same sets of plots (p < 0.01). PCT to 6 ft and 8 ft increased the production of 2×4 and 2×6 lumber over the control (p ≤ 0.04). Stand-level gross total product value increased between 11% and 23% in thinned stands (estimated at +$3000 to +$6600 per ha, p < 0.01). PCT had no appreciable effect on sawn lumber wood density (p ≥ 0.26) or lumber stiffness (MOE; ≤-6.2%, p ≥ 0.11), but had a negative effect on lumber strength (MOR; ≤ -13.4%, p ≤ 0.03) and wood basic density at stump height (≤- 7%; p < 0.01). MDF panel properties were generally good, regardless of spacing. We recommend thinning young balsam fir stands to a maximum nominal spacing of 6 ft (1.2 m) to maintain satisfactory lumber mechanical properties and maximize product value per hectare.

Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: Part 3 – Incidence of root and butt decay

2013 ◽  
Vol 89 (04) ◽  
pp. 464-473 ◽  
Author(s):  
Gary Warren ◽  
Patricia Baines ◽  
Jean Plamondon ◽  
Doug G. Pitt
Keyword(s):  
Forest Management ◽  
Value Chain ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Stand Age ◽  
Stem Form ◽  
Green River ◽  
Precommercial Thinning ◽  
Permanent Sample Plots ◽  
Butt Rot

The Green River precommercial thinning (PCT) trials were established between 1959 and 1961 in naturally regenerating balsam fir (Abies balsamea [L.] Mill.)-dominated stands an average of eight years after overstory removal. Three nominal spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate blocks. In the fall of 2008, following completion of the ninth sequential evaluation of the study’s 48 permanent sample plots, three of the six replicates were clearcut harvested; butt rot data were collected immediately afterwards. To date, forest management research and goals have focused on the benefits of PCT, such as increased tree size and merchantable volume, shorter rotation ages, and better stem form and uniformity. Comparatively little attention has been placed on negative aspects of PCT, such as the incidence and development of root and butt rots, and their impact on fibre yields and wood product values. Results from the Green River study provide evidence that PCT may increase the incidence of butt rot in balsam fir, with incidence proportional to thinning intensity (p < 0.01). We also observed incidence and volume of butt rot to increase with stem diameter (p ≤ 0.05). The experiment suggests that factors such as stand age at time of thinning, and age at the time of harvest are important considerations when it comes to mitigating the impacts of butt rot through forest management.

Long-term outcome of precommercial thinning in northwestern New Brunswick: growth and yield of balsam fir and red spruce

2008 ◽  
Vol 38 (3) ◽  
pp. 592-610 ◽  
Author(s):  
Doug Pitt ◽  
Len Lanteigne
Keyword(s):  
Block Design ◽  
Abies Balsamea ◽  
Red Spruce ◽  
Balsam Fir ◽  
Growth And Yield ◽  
Stem Volume ◽  
Long Term Outcome ◽  
Precommercial Thinning ◽  
Minimum Requirement

A study was established between 1959 and 1961 to study the long-term responses of balsam fir ( Abies balsamea (L.) Mill.) and red spruce ( Picea rubens Sarg.) to precommercial thinning. Three nominal spacings of 4 ft (1.2 m), 6 ft (1.8 m), and 8 ft (2.4 m) were compared with an unthinned control in a randomized complete block design with five replicates. At the time of thinning, natural regeneration averaged 16 years of age, 8 years after harvest. Although thinning had minimal effect on gross total volume production over a 42 to 44 year observation period, actual spacings between 2.1 and 2.5 m produced an average of 360 m3·ha–1gross merchantable volume (GMV), representing a 21% gain over unthinned stands. The same spacings produced quadratic mean diameters of 21 and 23 cm, respectively, compared with 18 cm in the unthinned stands. These size increases translated to individual stem volume gains of 33% and 62%, significantly reducing the age at which thinned stands would meet a specified minimum requirement for merchantability or habitat. The mean annual increment of GMV ranged from 6 m3·ha–1·year–1in unthinned stands, to more than 7 m3·ha·–1·year–1in the thinned stands, and had not yet culminated an average of 50 years postharvest.

Changes in root morphology after precommercial thinning in balsam fir stands

2003 ◽  
Vol 33 (12) ◽  
pp. 2452-2459 ◽  
Author(s):  
Jean-Claude Ruel ◽  
Catherine Larouche ◽  
Alexis Achim
Keyword(s):  
Radial Growth ◽  
Abies Balsamea ◽  
Stand Density ◽  
Balsam Fir ◽  
Cross Sectional ◽  
Beam Shape ◽  
Precommercial Thinning ◽  
Beneficial Effects ◽  
Density Control ◽  
Over Time

Precommercial thinning is often used to control stand density in naturally regenerated balsam fir (Abies balsamea (L.) Mill.) stands. Early stand density control could have beneficial effects on longer term stand stability through a modification of stem shape and root development. To assess the effect of precommercial thinning, two thinned and two unthinned stands were selected. Root sections were collected at 25 cm from the centre of the stem for all major roots (diameter greater than 2 cm). A disk was also cut at breast height level. From these disks, response in radial growth was determined. Detailed root measurements were taken on the sample disks to assess treatment effect on the following variables: asymmetry in root cross-sectional area (CSA) distribution, individual root shape, as well as changes in root shape over time. A quick and pronounced response in root growth occurred. This response was greater than that observed in the trunk. No asymmetry in root CSA distribution was observed at the stand level. Trees allocated more to radial growth above the biological centre of the root both in treated and control stands, but this trend was increased by thinning. Roots also tended to develop T-beam shapes over time, both in control and thinned stands. Most roots initially did not possess an I-beam shape and did not develop one during the course of the study. According to our results, trees respond quickly to the new growing conditions created by thinning by increasing biomass allocation to parts of the roots where mechanical stresses are greater.

Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: Part 1 – Roundwood production and stumpage value

2013 ◽  
Vol 89 (04) ◽  
pp. 446-457 ◽  
Author(s):  
Doug G. Pitt ◽  
Len Lanteigne ◽  
Michael K. Hoepting ◽  
Jean Plamondon
Keyword(s):  
Value Chain ◽  
Abies Balsamea ◽  
Stand Age ◽  
Annual Increment ◽  
Data Set ◽  
Individual Tree ◽  
Green River ◽  
Precommercial Thinning ◽  
Permanent Sample Plots ◽  
Sequential Evaluation

The Green River precommercial thinning trials were established between 1959 and 1961 in naturally regenerating balsam fir (Abies balsamea [L.] Mill.)-dominated stands, an average of eight years after overstory removal. Three nominal spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate blocks. In the fall of 2008, following completion of the ninth sequential evaluation of the study’s 48 permanent sample plots, three of the six replicates were clearcut harvested and data were collected on roundwood product recovery and value. These data were used to construct treatment-invariant (p ≥ 0.18) functions predicting product volume from tree diameter, allowing the volume of studwood, sawlogs and pulpwood to be predicted for the full Green River data set (all 6 replicates) through time. Mean annual increment of gross merchantable volume culminated in all treatments around stand age 45. Thinning to a nominal spacing of 6 ft, resulting in 1600 merchantable stems per ha by stand age 30, offered the best balance of individual tree and stand growth, producing 20% more gross merchantable volume and 26% more sawlog volume than unthinned stands, potentially increasing landowner stumpage revenues by 22% (p < 0.01). The sawlog volume produced in unthinned stands could be realized up to 15 years sooner in thinned stands, suggesting that PCT may offer substantive flexibility in balancing forest-level wood supply objectives.

Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: Part 2 – Efficiency gains in cut-to-length harvesting

2013 ◽  
Vol 89 (04) ◽  
pp. 458-463 ◽  
Author(s):  
Jean Plamondon ◽  
Doug G. Pitt
Keyword(s):  
Value Chain ◽  
Abies Balsamea ◽  
Green River ◽  
Precommercial Thinning ◽  
Permanent Sample Plots ◽  
Thinning Intensity ◽  
System Data ◽  
Sequential Evaluation ◽  
Harvesting Costs ◽  
Different Levels

The Green River precommercial thinning trials were established between 1959 and 1961 in naturally regenerating balsam fir (Abies balsamea [L.] Mill.)-dominated stands an average of eight years after overstory removal. Three nominal spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate blocks. In the fall of 2008, following completion of the ninth sequential evaluation of the study’s 48 permanent sample plots, three of the six replicates were clearcut harvested using a cut-to-length system; data were collected on harvesting, forwarding and loading efficiency. Largely due to increased average tree size, precommercially thinned stands were associated with improvements in both harvesting and forwarding productivity, proportional to thinning intensity. For example, the nominal 6-ft spacing yielded 30% to 35% gains in harvesting productivity, and 16% to 39% gains in forwarding productivity (p ≤ 0.04), these ranges spanning the different levels of operator expertise and block conditions observed. In total, estimated harvesting costs were $12.58/m3 in the unthinned stands, compared to $9.10/m3 in the 6-ft spaced stands (p = 0.02). Such a difference represents a $3.48/m3 savings, which translates into just over $1000 per ha, based on the gross merchantable volume produced in the 6-ft spaced stands.

scholarly journals Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: Part 6 – Estimating the economic benefits

2013 ◽  
Vol 89 (04) ◽  
pp. 502-511 ◽  
Author(s):  
Doug Pitt ◽  
Len Lanteigne ◽  
Michael K. Hoepting ◽  
Jean Plamondon ◽  
Isabelle Duchesne ◽  
...  
Keyword(s):  
Value Chain ◽  
Net Present Value ◽  
Abies Balsamea ◽  
Economic Benefits ◽  
Sensitivity Analyses ◽  
Deciduous Tree ◽  
Green River ◽  
Precommercial Thinning ◽  
Wood Processing ◽  
Silvicultural Treatments

The Green River precommercial thinning (PCT) trials were established between 1959 and 1961 in naturally regenerating balsam fir (Abies balsamea [L.] Mill.)-dominated stands an average of eight years after overstory removal. Following clearcut harvest of three of the study's six replicates in the fall of 2008, the rotation-length effects of PCT and vegetation management (VM; deciduous tree and brush suppression) on the forest value chain were integrated into a spreadsheet-based model that estimates the net present value (NPV) of these silvicultural treatments. Assuming costs and prices near recent values, both PCT and VM were observed to support positive landowner NPVs through discount rates in excess of 6%. At a discount rate of 4% and an age where sawlog production was maximized, PCT and VM offered similar NPV (>$550/ha). Landowners that can attract buyers willing to pay a premium for wood from thinned stands (equal to the sum of reduced operational overhead charges, harvesting and sawmilling costs and increased pulping costs) could see the value of their stands double. Sensitivity analyses revealed that these results are dependent on site productivity, silvicultural costs and a strong premium on sawlog stumpage rates. Depending on economic circumstances, PCT and VM could be attractive investments on high quality sites that are situated in close proximity to wood processing infrastructure.

scholarly journals Joint effects of CSN3 and LGB genes on milk quality and coagulation properties in Czech Fleckvieh

2008 ◽  
Vol 53 (No. 6) ◽  
pp. 246-252 ◽  
Author(s):  
A. Matějíček ◽  
J. Matějíčková ◽  
M. Štípková ◽  
O. Hanuš ◽  
V. Genčurová ◽  
...  
Keyword(s):  
Positive Impact ◽  
Production Quality ◽  
Positive Influence ◽  
Quality Parameters ◽  
Milk Quality ◽  
Progeny Testing ◽  
Joint Effects ◽  
Negative Effect ◽  
Milk Casein ◽  
True Protein

The aim of this study was to determine the joint effects of <I>CSN3</I> and <I>LGB</I> genotypes on parameters of production, quality and coagulation of milk in Czech Fleckvieh cows. Three hundred and twenty-eight Czech Fleckvieh cows were determined for <I>CSN3</I> (kappa-casein) and <I>LGB</I> (beta-lactoglobulin) genotypes using the PCR-RFLP method, milk quality parameters and coagulation properties. Milk production parameters were obtained from the Official Database of Progeny Testing. Fifteen genotype combinations were detected, with <I>ABAB</I> (21.0%) and <I>AAAB</I> (18.3%) occurring as the most frequent. The observed genes significantly affected the contents of milk protein (crude protein, true protein, casein and whey protein) as well as solid non-fat in milk, casein number and curd quality. <I>BBAA</I> was found to be the genotype with the highest positive impact on most of the milk characteristics evaluated. Whereas <I>ABBB, BBBB, BBAB</I> and <I>ABAB</I> had a positive influence on milk quality and milk coagulation properties, genotypes containing <I>CSN3</I> allele <I>E</I> had a negative effect. Results presented in this study are applicable in the selection of Czech Fleckvieh cattle.

Regeneration and stand development following a spruce budworm outbreak, spruce budworm inspired harvest, and salvage harvest

2012 ◽  
Vol 42 (10) ◽  
pp. 1759-1770 ◽  
Author(s):  
C. Eiry Spence ◽  
David A. MacLean
Keyword(s):  
Species Composition ◽  
Structural Characteristics ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Canopy Cover ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Stand Development ◽  
Eastern Canada ◽  
Precommercial Thinning

Spruce budworm ( Choristoneura fumiferana (Clemens)) (SBW) outbreaks are a major disturbance that influence stand dynamics and succession in balsam fir ( Abies balsamea (L.) Mill.) dominated forests of eastern Canada. We used stand and regeneration data collected from five plots in each of one immature and five mature stands before, during, and 30 years following the last major SBW outbreak in the Cape Breton Highlands to examine the role of stand and regeneration characteristics in shaping future stand development. Comparisons were also made between regeneration in four SBW outbreak stands versus two SBW salvage stands, with and without a subsequent precommercial thinning, and with 25 plots that underwent SBW emulation harvest. In mature unharvested balsam fir stands, species composition 30 years following the SBW outbreak was closely related to predisturbance species composition, and in immature fir stands, hardwood composition increased from 0% to 4%–27%. Species composition in harvested stands varied depending on whether intolerant hardwoods had been precommercially thinned, where thinned stands had 30% less hardwood 30 years postdisturbance than unthinned stands. Seedling density decreased by 17%–85% from 1979 to 1989 in all SBW outbreak stands, but average seedling height increased by 17%–500% as live canopy cover decreased from an average of 50% to 4%. Results suggest that advanced regeneration should be protected during harvest of balsam fir dominated stands, post-outbreak precommercial thinning will increase tree growth, and live tree retention can help develop late-seral structural characteristics in second-growth stands.

Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: A fifty-year legacy of forest research continues

2013 ◽  
Vol 89 (04) ◽  
pp. 439-445 ◽  
Author(s):  
Doug G. Pitt ◽  
Len Lanteigne ◽  
Michael K. Hoepting ◽  
James Farrell
Keyword(s):  
Value Chain ◽  
Stand Structure ◽  
Abies Balsamea ◽  
Stem Density ◽  
Tree Species Composition ◽  
Green River ◽  
Precommercial Thinning ◽  
Permanent Sample Plots ◽  
Commercial Thinning ◽  
Fibre Yield

Reduction of the stem density of young, naturally regenerating stands through precommercial thinning (PCT) is widely accepted as beneficial for controlling tree species composition, selecting crop trees and improving their growth, and preparing stand structure for subsequent commercial thinning. Less understood and accepted are the forest-level benefits associated with wood fibre yield and value as they relate to the financial returns of PCT. The Green River PCT trials were established between 1959 and 1961 in naturally regenerating balsam fir (Abies balsamea [L.] Mill.)-dominated stands an average of eight years after overstory removal. Three nominal spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate blocks. In the fall of 2008, following completion of the ninth sequential evaluation of the study’s 48 permanent sample plots, three of the six replicates were clearcut harvested and data were collected to quantify the effects of PCT on the forest value chain. This paper is the introduction to a series of six papers that quantify the rotation-length effects of PCT on: 1) stand dynamics and the yield of roundwood products; 2) harvesting and wood handling costs; 3) root and butt rot incidence, severity, and effects on volume recovery; 4) lumber and fibre-based panel recovery and value; 5) pulp and paper recovery and value; and 6) the overall integration of these costs and benefits.

scholarly journals Effects of precommercial thinning on the forest value chain in northwestern New Brunswick: Part 5 – Kraft and Thermomechanical pulping and pulp quality

2013 ◽  
Vol 89 (04) ◽  
pp. 490-501 ◽  
Author(s):  
Paul Bicho ◽  
Elmer Portillo ◽  
Bernard Yuen ◽  
Dongbo Yan ◽  
Doug G. Pitt
Keyword(s):  
Value Chain ◽  
Abies Balsamea ◽  
Wood Chip ◽  
Economic Benefits ◽  
Kraft Pulping ◽  
Wood Chips ◽  
Precommercial Thinning ◽  
Silvicultural Treatments ◽  
Thermomechanical Pulping ◽  
Main Effects

Forty-eight years after application, three nominal precommercial thinning (PCT) spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate, balsam fir (Abies balsamea [L.] Mill.)-dominated stands. Following the clearcut harvest of three of these replicates in 2008, chips produced from sawmilling trials (slab-wood) and from the top logs of the sampled trees (top-log) were kraft and thermomechanically (TMP) pulped. In general, top-log chips took longer to kraft pulp, had lower yields, and produced pulps with shorter, finer fibres than the corresponding slab-wood chips, across all PCT treatment levels. The main effects of PCT on pulping occurred with slab-wood chips and not top-log chips. While end-product quality in either kraft or TMP production was generally unaffected by wood from the range of thinnings tested, slight reductions in slab-wood chip density and H-factor suggest that kraft pulping productivity may be reduced by 1.8% with furnish from thinned stands. While these losses could be offset somewhat by lower chip consumption, the economic benefits for a kraft mill are marginal at best, and sharing of fiscal gains across the fibre value chain needs to be explored. Specific refining energy required in TMP production was, however, reduced by 4% with furnish from thinned stands. These results suggest that value-chain optimization is ultimately dependent on the segregation of fibre from different sources, including within-tree and among silvicultural treatments and sites.

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