Nondestructive Testing Technique to Quantify Deterioration from Marine Borer Attack in Sitka Spruce and Western Hemlock Logs: Observations from a Pilot Test

2014 ◽  
Author(s):  
Robert Ross ◽  
John W. Forsman ◽  
John R. Erickson ◽  
Allen M. Brackley
Keyword(s):  
Nondestructive Testing ◽  
Sitka Spruce ◽  
Western Hemlock ◽  
Pilot Test ◽  
Testing Technique

Laser speckle photometry: contactless nondestructive testing technique

2012 ◽  
Author(s):  
Ulana Cikalova ◽  
Juergen Nicolai ◽  
Beatrice Bendjus ◽  
Juergen Schreiber
Keyword(s):  
Nondestructive Testing ◽  
Laser Speckle ◽  
Testing Technique

Modeling specific gravity and diameter inside bark of western hemlock and Sitka spruce growing in southeast Alaska

2021 ◽  
Author(s):  
Joseph Dahlen ◽  
David Auty ◽  
Eini C. Lowell
Keyword(s):  
Specific Gravity ◽  
Fixed Effects ◽  
Sitka Spruce ◽  
Western Hemlock ◽  
Fit Indices ◽  
Southeast Alaska ◽  
Important Species ◽  
Explanatory Variables ◽  
Cambial Age ◽  
Young Growth

Western hemlock and Sitka spruce are two commercially important species in Alaska with harvests beginning to focus on naturally regenerated young-growth. We developed within-tree models of ring specific gravity (SG) and diameter inside bark (DIB) for young-growth western hemlock and Sitka spruce. Eight even-aged stands (age < 75 years) in southeast Alaska were felled and disks collected from multiple height levels; 128 trees and 451 disks were collected for western hemlock, and 217 trees and 952 disks were collected for Sitka spruce. Radial strips were prepared and scanned using X-ray densitometry. We fitted non-linear mixed-effects models to the data, with cambial age, height within tree, and dominance class used as explanatory variables. The R2 values (fixed effects only) for the SG models were 0.48 and 0.42 for western hemlock and Sitka spruce, respectively. The corresponding fit indices for the DIB models were 0.86 and 0.85 percent for western hemlock and Sitka spruce, respectively. Tree maps depicting the within tree variation in SG showed more variability in Sitka spruce than in western hemlock. The wood and growth properties of young-growth trees in Alaska will continue to become more important as the U.S. Forest Service transitions away from harvesting old-growth trees.

scholarly journals Response of Sitka spruce and western hemlock to commercial thinning.

1985 ◽  
Author(s):  
Joseph N. Graham ◽  
John F. Bell ◽  
Francis R. Herman
Keyword(s):  
Sitka Spruce ◽  
Western Hemlock ◽  
Commercial Thinning

Biomass Regressions for Understory Species in Young-Growth Sitka Spruce–Western Hemlock Forests of Southeast Alaska

2021 ◽  
Vol 95 (1) ◽  
Author(s):  
Annelise Z. Rue-Johns ◽  
Justin S. Crotteau ◽  
David V. D'Amore ◽  
Jeffrey C. Barnard
Keyword(s):  
Sitka Spruce ◽  
Western Hemlock ◽  
Southeast Alaska ◽  
Understory Species ◽  
Young Growth

What influences the long-term development of mixtures in British forests?

2020 ◽  
Vol 93 (4) ◽  
pp. 545-556 ◽  
Author(s):  
W L Mason ◽  
T Connolly
Keyword(s):  
Functional Traits ◽  
Scots Pine ◽  
Shade Tolerance ◽  
Basal Area ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Silver Birch ◽  
Western Hemlock ◽  
Larix Kaempferi ◽  
Pure Stand

Abstract Six experiments were established between 1955 and 1962 in different parts of northern and western Britain which used replicated randomized block designs to compare the performance of two species 50:50 mixtures with pure stands of the component species. The species involved were variously lodgepole pine (Pinus contorta Dougl.), Japanese larch (Larix kaempferi Lamb. Carr.), Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth.), Sitka spruce (Picea sitchensis Bong. Carr.) and western hemlock (Tsuga heterophylla Raf. Sarg.). The first four species are light demanding, while Sitka spruce is of intermediate shade tolerance and western hemlock is very shade tolerant: only Scots pine and silver birch are native to Great Britain. In three experiments (Bickley, Ceannacroc, Hambleton), the mixtures were of two light-demanding species, while at the other three sites, the mixture tested contained species of different shade tolerance. The experiments were followed for around 50 years, similar to a full rotation of even-aged conifer stands in Britain. Five experiments showed a tendency for one species to dominate in mixture, possibly reflecting differences in the shade tolerance or other functional traits of the component species. In the three experiments, the basal area of the mixtures at the last assessment was significantly higher than predicted based on the performance of the pure stands (i.e. the mixture ‘overyielded’). In two of these cases, the mixture had had a higher basal area than found in the more productive pure stand indicating ‘transgressive overyielding’. Significant basal area differences were generally more evident at the later assessment date. The exception was in a Scots pine: western hemlock mixture where greater overyielding at the earlier date indicated a nursing (‘facilitation’) effect. In the remaining experiments, the performance of the mixture conformed to predictions from the growth of the component species in pure stands. Taken overall, the results suggest that functional traits can be used to interpret the performance of mixtures but prediction of the outcome will require better understanding of the interplay between species and site characteristics plus the influence of silvicultural interventions.

Application of Stress Wave Reflection Method in Nondestructive Testing of Bolt

2012 ◽  
Vol 446-449 ◽  
pp. 2229-2233 ◽  
Author(s):  
Xian Kai Bao ◽  
Yi Li
Keyword(s):  
Nondestructive Testing ◽  
Stress Wave ◽  
Wave Reflection ◽  
Reflection Method ◽  
Testing Technique ◽  
The World ◽  
History Of ◽  
Estimate Quality

Bolt has been used widely in geoengineering all over the world in recent years, the testing technique of bolt develops quickly too. This paper summarizes simply the history of bolt testing technique, describes in detail stress wave reflection method. It is useful and valuable nondestructive.Testing method is verified with several parameters which estimate quality of bolting integrity.

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