Optimizing Surface Micro Grooving to Reduce the Checking and Cupping of Douglas Fir, Western Hemlock and White Spruce Decking Exposed to Natural Weathering

Machining grooves into the surface of pine and fir (Abies spp.) deckboards reduces undesirable checking that develops when “profiled” boards are exposed to the weather. We aim to develop improved profiles for Douglas fir, western hemlock and white spruce decking to reduce their susceptibility to checking, and understand how profile geometry influences the stresses that cause checking. We varied the width and depth of grooves in profiled deckboards, exposed deckboards to the weather, and measured checking and cupping of boards. A numerical model examined the effect of groove depth on the moisture-induced stresses in profiled spruce boards. Profiling significantly reduced checking, but increased cupping of deckboards made from all three species. Western hemlock checked more than the other two species. Profiles with narrow grooves (rib profiles) were better at restricting checking than profiles with wider grooves. A rib profile with deeper grooves developed smaller stresses than a rib profile with shallower grooves, and boards with the former profile checked less than boards with shallower grooves. We conclude that checking of profiled Douglas fir, western hemlock and white spruce decking is significantly reduced by changing profile geometry, and our results suggest the best profiles to reduce checking of all three species.

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A Note of the Positive Effects of Double-Sided Profiling on the Cupping and Checking of ACQ-Treated Douglas Fir, Western Hemlock and White Spruce Deckboards Exposed to Natural Weathering

Wood and Fiber Science ◽

10.22382/wfs-2020-022 ◽

2020 ◽

Vol 52 (2) ◽

pp. 243-253 ◽

Cited By ~ 1

Author(s):

Sina Heshmati ◽

Leung Luke ◽

Mohammad Sadegh Masloomi ◽

Philip David Evans

Keyword(s):

White Spruce ◽

Douglas Fir ◽

Western Hemlock ◽

Natural Weathering ◽

Positive Effects

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Filmforming Antitranspirants: Their Effects on Root Growth Capacity, Storability, Moisture Stress Avoidance, and Field Performance of Containerized Conifer Seedlings

The Forestry Chronicle ◽

10.5558/tfc60335-6 ◽

1984 ◽

Vol 60 (6) ◽

pp. 335-339 ◽

Cited By ~ 8

Author(s):

David G. Simpson

Keyword(s):

Root Growth ◽

Field Performance ◽

White Spruce ◽

Moisture Stress ◽

Douglas Fir ◽

Western Hemlock ◽

Growth Capacity ◽

Root Growth Capacity ◽

Stress Avoidance ◽

Vapor Gard

The antitranspirants, XEF-4-3561-A. Wilt Pruf, Plantgard, Folicote, Clear Spray, and Vapor Gard, were sprayed on container-grown lodgepole pine, white spruce, western hemlock, and Douglas-fir seedlings before or after a 12-week cold (+ 2 °C) storage period. The effects of the six antitranspirants on root growth capacity, storability, and field performance varied between species. XEF-4-3561-A. Wilt Pruf, Folicote, and Vapor Gard increased moisture stress avoidance of all species, while Plantgard and Clear Spray had no effect. None of the six antitranspirants are recommended for use on white spruce, western hemlock, or Douglas-fir planting stock because of the risk of reducing field performance. Further trials of XEF-4-3561-A and Wilt Pruf on lodgepolo pine seedlings seem War-ranted.

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Transforming even-aged coniferous stands to multi-aged stands: an opportunity to increase tree species diversity?

Forestry An International Journal of Forest Research ◽

10.1093/forestry/cpaa004 ◽

2020 ◽

Vol 93 (5) ◽

pp. 616-629

Author(s):

Gauthier Ligot ◽

Philippe Balandier ◽

Sophie Schmitz ◽

Hugues Claessens

Keyword(s):

Interspecific Competition ◽

Height Growth ◽

Douglas Fir ◽

The Other ◽

Western Hemlock ◽

Stand Age ◽

Specific Response ◽

Light Conditions ◽

Comparable Rate ◽

Advanced Regeneration

Abstract Transforming even-aged coniferous stands into multi-aged ones is attracting growing interest in Europe. However, applying this silvicultural treatment, maintaining a continuous cover and relying on natural regeneration require a deep understanding of the factors driving interspecific competition in the understorey. In particular, knowledge of species-specific response to different light conditions is needed to plan silvicultural treatments and forecast long-term stand composition. In this context, we assessed regeneration (±10–400 cm in height) and light conditions (±1–40 per cent of transmittance) in nine coniferous stands with ranging stand age (±20–120 years) and species composition (Norway spruce, Douglas fir, larch, silver fir and western hemlock) in Belgium. We then modelled interspecific differences in regeneration height growth to forecast the outcome of interspecific competition in different light conditions. Controlling understorey light seems an efficient way to control the interspecific competition, but with some limits, and taking into account sapling size. Maintaining low light conditions (transmittance < 15 per cent) probably reduces interspecific competition as it allows small saplings (height < 100 cm) of most species to grow at a comparable rate. Maintaining higher light conditions might allow a few species to rapidly overgrow the others. Species ranking in height growth changed across the studied light range only between spruce and larch, suggesting that the competition between these two species can be driven through the control of understorey light. On the other hand, controlling canopy openness was found to be insufficient, for example, to promote an advanced regeneration (height ≥ 200 cm) of fir over advanced regeneration of spruce, to promote any species over western hemlock or to promote Douglas fir. Western hemlock, a very shade-tolerant species, was found to grow three times faster than the other species in all the observed conditions (PACL = 5–20 per cent). Douglas fir saplings showed weak growth and marked defoliation, which we hypothetically relate to the recent outbreak of Contarinia pseudotsugae in Western Europe.

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THE 1951 AERIAL BAITING AND SEEDING PROJECT, ASH RIVER TRACT, MacMILLAN AND BLOEDEL LIMITED

The Forestry Chronicle ◽

10.5558/tfc31045-1 ◽

1955 ◽

Vol 31 (1) ◽

pp. 45-59 ◽

Cited By ~ 1

Author(s):

G. S. Allen ◽

I. K. Barber ◽

Ian Mahood

Keyword(s):

West Coast ◽

Forest Service ◽

Douglas Fir ◽

Western Hemlock ◽

Local Distribution ◽

Rodent Control ◽

Buffer Strip ◽

Minimum Standards ◽

Service Standards ◽

Forestry Practice

An area of 738 acres about 20 miles north and west of Port Alberni on Vancouver Island was seeded by helicopter to Douglas fir (1/2 pound per acre) and western hemlock (1/5 pound per acre) in November 1951. One week earlier this area and a surrounding buffer strip, totalling 1760 acres, had been baited by helicopter using wheat treated with thallous sulphate and "1080".Baiting was successful and the roden:trap ratio dropped from 1:4.6 to 1:94.3 as a result. By April the ratio had climbed again to 1:18.7. By the first week of June 1952, a total of about 1400 Douglas fir and 840 hemlock had germinated per acre. By November 1952, this had dropped to 1000 Douglas fir and 198 hemlock per acre. A final extensive survey in June 1954, showed a total of 730 Douglas fir and 57 hemlock of the 1952 crop per acre with a milacre stocking of 42.0 percent for Douglas fir and 43.9 percent for Douglas fir and hemlock. The 4-milacre stocking due to the 1952 Douglas fir seedlings was 78.3 percent. Practically all of the seedlings that germinated in 1952 are attributed to the seeding operation because of the relatively uniform distribution of seedlings and the lack of seedlings on the control area.The seeding operation in itself restocked 628 acres to B.C. Forest Service minimum standards (31 percent by 1-milacres). It restocked 708 acres to U.S. "medium" or "good" standards. With natural trees included, only 28 acres are below B.C. Forest Service standards, and 6 acres below U.S. "medium" stocking. Total stocking, including natural trees, is 59.3 percent by 1-milacres and 88.6 percent by 4-milacres.The baiting and seeding operation can be considered highly successful. The surviving Douglas firs are healthy and vigorous and show little deer or grouse damage to date. Distribution of the seedlings is good and most gaps that occurred are believed due to uneven local distribution of seed. Considering that this experiment was carried out on a rather steep south exposure and that the first summer following seeding was unusually hot and dry, the satisfactory results suggest that direct seeding following rodent control has a definite place in West Coast forestry practice. It may well take the place of more expensive and troublesome planting on many areas that are slow to restock.

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Xenomeris Abietis Associated with Dieback of Douglas Fir and Western Hemlock

Mycologia ◽

10.1080/00275514.1971.12019136 ◽

1971 ◽

Vol 63 (3) ◽

pp. 567-574 ◽

Cited By ~ 3

Author(s):

A. Funk ◽

R. A. Shoemaker

Keyword(s):

Douglas Fir ◽

Western Hemlock

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Growth ofPseudotsuga menziesiiandTsuga heterophyllaseedlings along a light gradient: resource allocation and morphological acclimation

Canadian Journal of Botany ◽

10.1139/b97-857 ◽

1997 ◽

Vol 75 (9) ◽

pp. 1424-1435 ◽

Cited By ~ 32

Author(s):

D. Mailly ◽

J. P. Kimmins

Keyword(s):

Leaf Morphology ◽

Biomass Accumulation ◽

Tsuga Heterophylla ◽

Douglas Fir ◽

Western Hemlock ◽

Low Light ◽

Growing Seasons ◽

Light Levels ◽

Light Gradient ◽

Relative Light Intensity

Silvicultural alternatives that differ in the degree of overstory removal may create shady environments that will be problematic for the regeneration of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Gradients of light in the field were used to compare mortality, growth, and leaf morphological acclimation of two conifer species of contrasting shade tolerances: Douglas-fir and western hemlock (Tsuga heterophylla (Raf.) Sarg.). Results after two growing seasons indicated that Douglas-fir mortality occurred mainly at relative light intensity (RLI) below 20%, while western hemlock mortality was evenly distributed along the light gradient. Height, diameter, and biomass of the planted seedlings increased with increasing light for both species but at different rates, and maximum biomass accumulation always occurred in the open. Douglas-fir allocated more resources to stem biomass than western hemlock, which accumulated more foliage biomass. Increases in specific leaf area for Douglas-fir seedlings occurred at RLI ≤ 0.4 and red/far red (R/FR) ratio ≤ 0.6, which appear to be the minimal optimum light levels for growth. Conversely, western hemlock seedlings adjusted their leaf morphology in a more regular pattern, and changes were less pronounced at low light levels. These results, along with early mortality results for Douglas-fir, suggest that the most successful way to artificially regenerate this species may be by allowing at least 20% of RLI for ensuring survival and at least 40% RLI for optimum growth. Key words: light, light quality, leaf morphology, acclimation.

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R-55 Rodent Repellent: Effect on Germination in Douglas-fir and Western Hemlock.

Canadian Journal of Forest Research ◽

10.1139/x72-042 ◽

1972 ◽

Vol 2 (3) ◽

pp. 256-263 ◽

Cited By ~ 3

Author(s):

D. G. W. Edwards ◽

Patricia E. Olsen

Keyword(s):

Graphite Powder ◽

Douglas Fir ◽

Western Hemlock ◽

Repellent Effect ◽

Dry Storage

Coating Douglas-fir and western hemlock seeds with R-55, a rodent repellent, seriously reduced normal germination. Acidifying the latex sticker, or adding graphite powder, had no effect. If seeds were coated first with latex, more R-55 could be applied without significantly increasing germination losses. Both stratification and dry storage of R-55 coated seeds increased germination losses. Treatment differences detected by normal germination percentages were also reflected in germination values. Observations based on total (normal + abnormal) germination obscured the effects of the various coatings.

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Partial cut harvesting and ectomycorrhizae: early effects in Douglas-fir-larch forests of western Montana

Canadian Journal of Forest Research ◽

10.1139/x80-071 ◽

1980 ◽

Vol 10 (3) ◽

pp. 436-440 ◽

Cited By ~ 24

Author(s):

A. E. Harvey ◽

M. J. Larsen ◽

M. F. Jurgensen

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Douglas Fir ◽

The Other ◽

Western Montana ◽

Root Tips ◽

Residue Removal ◽

Larch Forests ◽

Early Effects

Numbers of ectomycorrhizae were assessed 3 years after harvesting approximately 50% of the overstory in two Douglas-fir-larch stands in western Montana, one was subjected to intensive residue removal, the other broadcast burned 1 year after harvest. Numbers of active ectomycorrhizal root tips were significantly reduced in the broadcast burned stand compared to either the intensively utilized stand or to an adjacent, undisturbed stand. This indicates that on difficult-to-regenerate sites, particularly where soil organic matter is low, it may be advantageous to dispose of slash created in partial cuts by means other than burning.

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Practical Aspects of Propulsion Shaft Alignment

10.5957/some-2021-012 ◽

2021 ◽

Author(s):

Kyriakos Avgouleas ◽

Emmanouil Sarris ◽

George Gougoulidis

Keyword(s):

Cost Effectiveness ◽

Numerical Model ◽

High Speed ◽

The Other ◽

Technical Literature ◽

Trade Off ◽

Fea Model ◽

Shaft Alignment ◽

Alignment Strategy ◽

Potential Damage

The economical and operational implications of poor alignment are indisputable for the propulsion shafting system of a commercial vessel. This holds true for naval vessels as well, although far less documented in the technical literature. This paper addresses some of the challenges associated with the proper alignment of a high-speed naval craft, which has been in service for many years. Laser bore-sighting was performed on a Guided Missile Fast Patrol Boat resting on a docking cradle. The measured bearing offsets were input to a FEA model of the shafting system to calculate bearing reactions and detect potential misalignment issues. Subsequent decisions regarding corrective measures take into account the results computed by the numerical model, experience from sister ships, the available documentation from the building yard and several other factors which are discussed in the paper. The solutions proposed are targeted towards a balanced trade-off between cost effectiveness and out-of-service time on one hand, and the risk of potential damage from misalignment on the other hand, which would seriously disrupt the ship’s operational availability. Practical aspects and lessons identified in the process are also presented, which demonstrate the distinct differences in alignment strategy of a high-speed naval craft compared to a typical commercial vessel.

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