scholarly journals Dichotomous Keys for Scaling and Grading Merchantable Quality Sawlogs

2003 ◽  
Vol 18 (4) ◽  
pp. 250-258
Author(s):  
Steve Bowers
Keyword(s):  
Pseudotsuga Menziesii ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Advisory Group ◽  
Time Scaling ◽  
Dichotomous Key ◽  
Second Growth ◽  
Group A ◽  
Length Scaling ◽  
Log Scaling

Abstract This study documented and field-tested a simplified version of the Westside Grading Guidelines as published in the Official Rules Handbook by the Northwest Log Rules Advisory Group. A four-step dichotomous key was documented and field-tested to determine merchantable vs. nonmerchantable logs. The study also documented and field-tested an individual seven-step dichotomous log grading key for evaluating second-growth Douglas-fir (Pseudotsuga menziesii), Sitka spruce (Picea sitchensis), western hemlock (Tsuga heterophylla), and grand fir (Abies grandis) as derived from the Rules For Grading Logs section of the Official Rules Handbook. Results were compared with certified scalers employed by Yamhill Log Scaling & Grading Bureau and Columbia River Log Scaling & Grading Bureau. Eighty-four individuals measured the length, scaling diameter, determined merchantability versus nonmerchantability and assigned log grade for 440 logs. Results showed participants in the study correctly measuring log length 99% of time, scaling diameters were recorded correctly at an 89% rate, and merchantability and log grade at 98 and 97%, respectively. West. J. Appl. For. 18(4):250–258.

Distribution of leaf orientations in six conifer species

2001 ◽  
Vol 79 (4) ◽  
pp. 389-397 ◽  
Author(s):  
Hugh J Barclay
Keyword(s):  
Pseudotsuga Menziesii ◽  
Pinus Contorta ◽  
Goodness Of Fit ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
The Other ◽  
Thuja Plicata ◽  
Leaf Angle ◽  
Conifer Species ◽  
Abies Grandis

Leaf angle distributions are important in assessing both the flexibility of a plant's response to differing daily and seasonal sun angles and also the variability in the proportion of total leaf area visible in remotely sensed images. Leaf angle distributions are presented for six conifer species, Abies grandis (Dougl. ex D. Don) Lindl., Thuja plicata Donn. ex D. Don, Tsuga heterophylla (Raf.) Sarg., Pseudotsuga menziesii (Mirb.) Franco, Picea sitchensis (Bong.) Carr. and Pinus contorta Dougl. ex Loud. var. latifolia. The leaf angles were calculated by measuring four foliar quantities, and then the distributions of leaf angles are cast in three forms: distributions of (i) the angle of the long axis of the leaf from the vertical for the range 0–180°; (ii) the angle of the long axis of the leaf for the range 0–90°; and (iii) the angle of the plane of the leaf for the range 0–90°. Each of these are fit to the ellipsoidal distribution to test the hypothesis that leaf angles in conifers are sufficiently random to fit the ellipsoidal distribution. The fit was generally better for planar angles and for longitudinal angles between 0° and 90° than for longitudinal angles between 0° and 180°. The fit was also better for Tsuga heterophylla, Pseudotsuga menziesii, Picea sitchensis, and Pinus contorta than for Abies grandis and Thuja plicata. This is probably because Abies and Thuja are more shade tolerant than the other species, and so the leaves in Abies and Thuja are preferentially oriented near the horizontal and are much less random than for the other species. Comparisons of distributions on individual twigs, whole branches, entire trees, and groups of trees were done to test the hypothesis that angle distributions will depend on scale, and these comparisons indicated that the apparent randomness and goodness-of-fit increased on passing to each larger unit (twigs up to groups of trees).Key words: conifer, leaf angles, ellipsoidal distribution.

Retention of needles and seeds on logs in Picea sitchensis – Tsuga heterophylla forests of coastal Oregon and Washington

1989 ◽  
Vol 67 (6) ◽  
pp. 1833-1837 ◽  
Author(s):  
Mark E. Harmon
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Survival ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Tree Recruitment ◽  
Rotten Wood

Logs are a major seedbed in Picea sitchensis – Tsuga heterophylla forests; therefore, the interception and retention of seeds on these surfaces is a potential limitation on tree recruitment. The ability of log surfaces within Picea – Tsuga forests to retain needles and seeds was studied at Cascade Head Experimental Forest, Oregon. Moss- and litter-covered surfaces retained many (48–98%) of the seeds and needles placed on them, but rotten wood, sound wood, and bark of Tsuga heterophylla, Picea sitchensis, and Pseudotsuga menziesii retained few (0–8%). Examination of logs mapped in five Picea sitchensis – Tsuga heterophylla stands in Oregon and Washington indicated a mean projected log cover of 9.9%. Thin (<5 cm) and thick (>5 cm) moss mats were the most abundant log surfaces and covered 59 and 25% of the logs, respectively. Analysis of data on seedbed coverage, retentive characteristics, and seedbed-specific seedling survival indicated approximately 1% of a seed cohort would survive the 1st year on log surfaces.

Interaction among deer browsing, hunting, and tree regeneration

2002 ◽  
Vol 32 (7) ◽  
pp. 1254-1264 ◽  
Author(s):  
Jean-Louis Martin ◽  
Christophe Baltzinger
Keyword(s):  
Species Interactions ◽  
Human Impacts ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Tree Regeneration ◽  
Thuja Plicata ◽  
Deer Hunting ◽  
Queen Charlotte Islands ◽  
Second Growth ◽  
The Impact

The intentional removal or addition of species or specific human impacts on ecosystems trigger changes that can help us understand species interactions. In many temperate forests, deer populations are increasing and so is the need to understand how they influence ecosystems. We took advantage of the introduction of Sitka black-tailed deer (Odocoileus hemionus sitchensis Merriam) to the Queen Charlotte Islands (Haida Gwaii), British Columbia, Canada, to study how hunting pressure affects the impact of deer on tree regeneration after logging. We show that although the regeneration of western redcedar (Thuja plicata Donn ex D. Don) is drastically reduced in presence of deer, regeneration is better and browsing stress lower, in areas where deer are more exposed to hunting. Similar effects of accessibility for hunters are observed on browsing stress of Sitka spruce (Picea sitchensis (Bong.) Carrière). Western hemlock (Tsuga heterophylla (Raf.) Sarg.) is not significantly affected, and its regeneration is not correlated to hunting. We suggest that the effect of hunting on tree regeneration could be explained by the incidence of hunting on deer behaviour rather than by the actual number of deer killed by hunters. These results suggest that the future occurrence of redcedar stands in second-growth forests on this archipelago may depend on the amount and distribution of deer hunting.

Survival dynamics of mechanically topped Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) snags in Douglas-fir plantations, Oregon, USA

2019 ◽  
Vol 433 ◽  
pp. 105-110
Author(s):  
Matthew E. Hane ◽  
Andrew J. Kroll ◽  
Aaron Springford ◽  
Jack Giovanini ◽  
Mike Rochelle ◽  
...  
Keyword(s):  
Pseudotsuga Menziesii ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock

scholarly journals Holocene biogeography of Tsuga mertensiana and other conifers in the Kenai Mountains and Prince William Sound, south-central Alaska

The Holocene ◽  
2016 ◽  
Vol 27 (4) ◽  
pp. 485-495 ◽  
Author(s):  
R Scott Anderson ◽  
Darrell S Kaufman ◽  
Edward Berg ◽  
Caleb Schiff ◽  
Thomas Daigle
Keyword(s):  
Climatic Factors ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Early Holocene ◽  
Ice Age ◽  
Prince William Sound ◽  
Conifer Forest ◽  
The Holocene ◽  
South Central ◽  
Tsuga Mertensiana

Several important North American coastal conifers – having immigrated during the Holocene from the southeast – reach their northern and upper elevation limits in south-central Alaska. However, our understanding of the specific timing of migration has been incomplete. Here, we use two new pollen profiles from a coastal and a high-elevation site in the Eastern Kenai Peninsula–Prince William Sound region, along with other published pollen records, to investigate the Holocene biogeography and development history of the modern coastal Picea (spruce)– Tsuga (hemlock) forest. Tsuga mertensiana became established at Mica Lake (100 m elevation, near Prince William Sound) by 6000 cal. BP and at Goat Lake (550 m elevation in the Kenai Mountains) sometime after 3000 years ago. Tsuga heterophylla was the last major conifer to arrive in the region. Although driven partially by climate change, major vegetation changes during much of the Holocene are difficult to interpret exclusively in terms of climate, with periods of slow migration alternating with more rapid movement. T. mertensiana expanded slowly northeastward in the early Holocene, compared with Picea sitchensis or T. heterophylla. Difficulty of invading an already established conifer forest may account for this. We suggest that during the early Holocene, non-climatic factors as well as proximity to refugia, influenced rates of migration. Climate may have been more important after ~2600 cal. BP. Continued expansion of T. mertensiana at Goat Lake at the Medieval Climate Anomaly (MCA)–‘Little Ice Age’ (‘LIA’) transition suggests warm and wet winters. But expansion of T. mertensiana at both sites was arrested during the colder climate of the ‘LIA’. The decline was more extensive at Goat Lake, where climatic conditions may have been severe enough to reduce or eliminate the T. mertensiana population. T. mertensiana continued its expansion around Goat Lake after the ‘LIA’.

Susceptibility of Western Conifers to Laminated Root Rot (Phellinus weirii) in Oregon and British Columbia Field Tests

1993 ◽  
Vol 8 (2) ◽  
pp. 67-70 ◽  
Author(s):  
E. E. Nelson ◽  
Rona N. Sturrock
Keyword(s):  
British Columbia ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Root Rot ◽  
Field Tests ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Giant Sequoia ◽  
Phellinus Weirii

Abstract Several species of conifers were outplanted around infected stumps in Oregon and British Columbia to measure their susceptibility to laminated root rot caused by Phellinus weirii. Grand fir (Abies grandis) experienced nearly 30% mortality caused by P. weirii. Douglas-fir (Pseudotsuga menziesii) mortality exceeded 20%. Noble fir (A. procera), Sitka spruce (Picea sitchensis), giant sequoia (Sequoiadendron giganteum), western hemlock (Tsuga heterophylla), and ponderosa pine (Pinus ponderosa) mortality averaged less than 10%. Western white pine (P. monticola) and lodgepole pine (P. contorta) mortality was less than 1%. Phellinus weirii did not cause mortality of western redcedar (Thuja plicata) or redwood (Sequoia sempervirens). Apparent susceptibility, based on mortality over 17-20 growing seasons, was similar to that recorded in past field observations. West. J. Appl. For. 8(2):67-70.

Lichen habitat may be enhanced by thinning treatments in young Tsuga heterophylla-Pseudotsuga menziesii forests

2010 ◽  
Vol 113 (2) ◽  
pp. 292-307 ◽  
Author(s):  
Heather T. Root ◽  
Bruce McCune ◽  
Peter Neitlich
Keyword(s):  
Pseudotsuga Menziesii ◽  
Tsuga Heterophylla

scholarly journals A quantitative study of cotyledon positioning in conifer development

Botany ◽  
2016 ◽  
Vol 94 (11) ◽  
pp. 1063-1074 ◽  
Author(s):  
David M. Holloway ◽  
Byron Brook ◽  
JooHyun Kang ◽  
Cameron Wong ◽  
Michael Wu
Keyword(s):  
Pseudotsuga Menziesii ◽  
Quantitative Study ◽  
Growth Regulator ◽  
Auxin Transport ◽  
Picea Sitchensis ◽  
Common Mechanism ◽  
Developmental Patterns ◽  
Second Stage ◽  
Spacing Distance ◽  
Naphthylphthalamic Acid

The number of cotyledons in angiosperm monocots and dicots is tightly constrained. But in the gymnosperm Pinaceae (pine family), which includes many of the conifers, cotyledon number (nc) can vary widely, commonly from 2 to 12. Conifer cotyledons form in whorled rings on a domed embryo geometry. We measured the diameter of embryos and counted the cotyledons to determine the radial positioning of the whorl and the circumferential spacing between cotyledons. Results were similar between Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), Sitka spruce (Picea sitchensis (L.) H.Karst.), and larch (Larix × leptoeuropaea, synonymous with L. × marschlinsii Coaz), indicating a common mechanism for cotyledon positioning in conifers. Disrupting transport of the growth regulator auxin (with 1-N-naphthylphthalamic acid (NPA)) led to cup-shaped embryos, indicating that whorl (ring) formation is separable from cotyledon patterning within the ring. NPA inhibits cotyledon outgrowth, but not the spacing (distance) between cotyledons. The NPA effect is direct; it does not operate indirectly on embryo size. These results support a hierarchical model for cotyledon positioning in conifers, in which a first stage (not requiring auxin transport) sets the whorl position, constraining the second stage (which requires auxin transport) to form cotyledons within this whorl. Similarly, recent studies in Arabidopsis have shown that different components of complex developmental patterns can have different transport properties; this aspect of patterning may be shared across plants.

scholarly journals Porcupine Feeding Damage in Precommercially Thinned Conifer Stands of Central Southeast Alaska

1997 ◽  
Vol 12 (4) ◽  
pp. 115-121 ◽  
Author(s):  
Andris Eglitis ◽  
Paul E. Hennon
Keyword(s):  
Host Selection ◽  
Sitka Spruce ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Western Hemlock ◽  
Feeding Damage ◽  
Southeast Alaska ◽  
Erethizon Dorsatum ◽  
Young Growth

Abstract This study describes feeding damage by porcupines (Erethizon dorsatum) in precommercially thinned young growth stands of Sitka spruce (Picea sitchensis) and western hemlock (Tsuga heterophylla) on Mitkof Island in central southeast Alaska. We examined 641 trees from 54 sampling plots along transect lines in three 12 to 20 yr old stands. Porcupine feeding was monitored each spring and fall from 1985 to 1987. Four categories of feeding damage are described: complete girdling of the bole, partial girdling (bole scars), branch clipping, and "tasting wounds" (small basal bole scars). Sitka spruce, the primary crop tree in these thinned stands, sustained significantly higher damage (52% of trees affected) than western hemlock (26% of trees affected). Porcupine feeding was greater on taller than shorter Sitka spruce. Although only 8 of 59 trees initially girdled in 1985 were killed, many later sustained additional feeding damage. Following the 1987 season 3 yr after thinning, nearly 30% of the spruce and 14% of the western hemlock crop trees had been partially or completely girdled. Issues deserving future attention include the role of thinning in predisposing stands to porcupine damage, methods of population assessment, and mechanisms of host selection by porcupines. West. J. Appl. For. 12(4):115-121.

scholarly journals To CAG or not to CAG? Difficulties in determining submission to the Confidentiality Advisory Group: a commentary

2020 ◽  
pp. 174701612092006
Author(s):  
V Ranieri ◽  
H Stynes ◽  
E Kennedy
Keyword(s):  
Informed Consent ◽  
Health Research ◽  
Local Information ◽  
Advisory Group ◽  
Primary Role ◽  
The Public ◽  
Confidential Data ◽  
Information Governance ◽  
Group A

The Confidentiality Advisory Group (CAG) is a specialised body that advises the Health Research Authority (HRA) and the Secretary of State for Health on requests for access to confidential information, in the absence of informed consent from its owners. Its primary role is to oversee the safe use of such information and to counsel the governing bodies mentioned above as to whether such use is appropriate or inappropriate. Researchers who seek access to England or Wales-based confidential data, for medical purposes that are in the interest of the public, are typically required to submit an application to this body. However, it is not always clear to researchers whether requests for access to patient data fit within the remit of the CAG or a Trust’s local information governance team. This commentary will, therefore, explore the role of the CAG and reflect on how best to support researchers with this question.

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