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.

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 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.

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 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.

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.

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.

Evaluating the effect of precommercial thinning on the resistance of balsam fir to windthrow through experimentation, modelling, and development of simple indices

2005 ◽  
Vol 35 (8) ◽  
pp. 1844-1853 ◽  
Author(s):  
A Achim ◽  
J -C Ruel ◽  
B A Gardiner
Keyword(s):  
New Brunswick ◽  
Gradual Increase ◽  
Abies Balsamea ◽  
Basal Area ◽  
Balsam Fir ◽  
Green River ◽  
Precommercial Thinning ◽  
Wind Speeds ◽  
Commercial Thinning ◽  
The Relationship

A tree-pulling experiment was carried out in stands of balsam fir (Abies balsamea (L.) Mill.) to evaluate the effects of early thinning on windthrow resistance. Forty trees from four stands were pulled over. Two stands had received a precommercial thinning 9 and 14 years previously, respectively, and the two others were unthinned controls. There were no significant inter-stand differences in the relationship between the critical turning moments required to overturn or snap the trees and their stem mass. The results were input into a model calculating critical wind speeds using the approach developed for the ForestGALES model. Simulations were run for four different stand densities. The mensurational characteristics for each run were taken from the results of a spacing trial established in balsam fir stands at Green River, New Brunswick. For stem breakage, the model predicted a gradual increase in critical wind speeds with wider spacing. The increase was smaller for tree overturning. The pattern of differences remained very similar after a simulated commercial thinning removing 30% of the basal area. Reductions in critical wind speeds were on the order of 4 m·s–1 in all cases. Simple indices were developed that could estimate the relative results given by the model.

scholarly journals Legacy effects of precommercial thinning on the natural regeneration of next rotation balsam fir stands in eastern Canada

Silva Fennica ◽  
2019 ◽  
Vol 53 (4) ◽  
Author(s):  
Claudie-Maude Canuel ◽  
Nelson Thiffault ◽  
Michael Hoepting ◽  
James Farrell
Keyword(s):  
Woody Debris ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Legacy Effects ◽  
Tree Species Diversity ◽  
Eastern Canada ◽  
Green River ◽  
Precommercial Thinning ◽  
Climate Conditions ◽  
Legacy Effect

The Green River precommercial thinning (PCT) trial was established between 1959–1961 in New Brunswick (Canada) within natural balsam fir ( (L.) Mill.)-dominated stands. Three silviculture scenarios differing only by the increasing nominal spacings of PCT treatments (1.2 m, 1.8 m, 2.4 m) were compared to an unthinned control within randomized replicates that were clearcut harvested in 2008 and treated with herbicide in 2011. During the fourth post-harvest growing season, we assessed regeneration, competing vegetation and coarse woody debris (CWD; differentiated between large woody debris and slash) to assess the legacy effects of PCT on regeneration of next rotation stands. Our results confirmed that silviculture scenarios including PCT significantly increased conifer stocking in treated plots compared to control conditions, but only in the 1.8 m nominal spacing. Considering that treated and untreated stands were fully stocked, we conclude that PCT using the spacing gradient tested has no legacy effect on the regeneration of next rotation natural balsam fir stands. Given the known sensitivity of balsam fir to future climate conditions in this region, we suggest that future treatments should promote tree species diversity to support ecosystem resilience to climate change by favouring more warm-adapted species, such as some hardwoods.Abies balsamea

scholarly journals Precommercial Thinning Increases Spruce Yields in Boreal Mixedwoods in Alberta, Canada

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 412
Author(s):  
Ivan Bjelanovic ◽  
Phil Comeau ◽  
Sharon Meredith ◽  
Brian Roth
Keyword(s):  
Growth Models ◽  
Growth And Yield ◽  
Diameter Growth ◽  
Growth Responses ◽  
Projection System ◽  
Precommercial Thinning ◽  
Thinning Intensity ◽  
Boreal Mixedwoods ◽  
Using Data ◽  
Mixedwood Stands

A few studies in young mixedwood stands demonstrate that precommercial thinning of aspen at early ages can improve the growth of spruce and increase stand resilience to drought. However, information on tree and stand responses to thinning in older mixedwood stands is lacking. To address this need, a study was initiated in 2008 in Alberta, Canada in 14 boreal mixedwood stands (seven each at ages 17 and 22). This study investigated growth responses following thinning of aspen to five densities (0, 1000, 2500, 5000 stems ha−1 and unthinned (control)). Measurements were collected in the year of establishment, and three and eight years later. Mortality of aspen in the unthinned plots was greater than in the thinned plots which were not significantly different amongst each other. Eight years following treatment, aspen diameter was positively influenced by thinning, while there was no effect on aspen height. The density of aspen had no significant effect on the survival of planted spruce. Spruce height and diameter growth increased with both aspen thinning intensity and time since treatment. Differentiation among treatments in spruce diameter growth was evident three years from treatment, while differentiation in height was not significant until eight years following treatment. Yield projections using two growth models (Mixedwood Growth Model (MGM) and Growth and Yield Projection System (GYPSY)) were initialized using data from the year eight re-measurements. Results indicate that heavy precommercial aspen thinning (to ~1000 aspen crop trees ha−1) can result in an increase in conifer merchantable volume without reducing aspen volume at the time of harvest. However, light to moderate thinning (to ~2500 aspen stems ha−1 or higher), is unlikely to result in gains in either deciduous or conifer merchantable harvest volume over those of unthinned stands.

scholarly journals Design for Circularity Guidelines for the EEE Sector

2021 ◽  
Vol 13 (7) ◽  
pp. 3923
Author(s):  
Anton Berwald ◽  
Gergana Dimitrova ◽  
Thijs Feenstra ◽  
Joop Onnekink ◽  
Harm Peters ◽  
...  
Keyword(s):  
Value Chain ◽  
Electronic Equipment ◽  
Decision Makers ◽  
Hazardous Substances ◽  
Easy Access ◽  
Stakeholder Collaboration ◽  
Weee Recycling ◽  
Negative Impacts ◽  
Multi Stakeholder ◽  
Different Levels

The increased diversity and complexity of plastics used in modern devices, such as electrical and electronic equipment (EEE), can have negative impacts on their recyclability. Today, the main economic driver for waste electrical and electronic equipment (WEEE) recycling stems from metal recovery. WEEE plastics recycling, on the other hand, still represents a major challenge. Strategies like design ‘for’, but also the much younger concept of design ‘from’ recycling play a key role in closing the material loops within a circular economy. While these strategies are usually analysed separately, this brief report harmonises them in comprehensive Design for Circularity guidelines, established in a multi-stakeholder collaboration with industry leaders from the entire WEEE value chain. The guidelines were developed at the product and part levels. They are divided in five categories: (1) avoidance of hazardous substances; (2) enabling easy access and removal of hazardous or polluting parts; (3) use of recyclable materials; (4) use of material combinations and connections allowing easy liberation; (5) use of recycled materials. These guidelines are the first harmonised set to be released for the EEE industry. They can readily serve decision-makers from different levels, including product designers and manufacturers as well as policymakers.

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