Height and crown width related to diameter for open-grown western hemlock and Sitka spruce

1989 ◽  
Vol 19 (9) ◽  
pp. 1203-1207 ◽  
Author(s):  
Wilbur A. Farr ◽  
Donald J. DeMars ◽  
J. Edward Dealy
Keyword(s):  
British Columbia ◽  
Sitka Spruce ◽  
Site Index ◽  
Western Hemlock ◽  
Queen Charlotte Islands ◽  
Crown Width

Data from 157 open-grown Sitka spruce (Piceasitchensis (Bong.) Carr.) and 102 western hemlock (Tsugaheterophylla (Raf.) Sarg.) at two locations in coastal Alaska and from 69 Sitka spruce on the Queen Charlotte Islands in British Columbia were used to develop height–diameter and crown width–diameter equations. Height–diameter relations for Sitka spruce were significantly different among all locations. Crown width–diameter relations were not significantly different. Common equations were fit to the spruce data and to the spruce and hemlock data independent of location and site index along the coast.

A Sitka spruce height-age model with improved extrapolation properties

1997 ◽  
Vol 73 (3) ◽  
pp. 363-369 ◽  
Author(s):  
Gordon D. Nigh
Keyword(s):  
British Columbia ◽  
Serial Correlation ◽  
Sitka Spruce ◽  
Analysis Data ◽  
Site Index ◽  
Picea Sitchensis ◽  
Stem Analysis ◽  
Queen Charlotte Islands ◽  
Extrapolation Model ◽  
Age Model

The height-age model for Sitka spruce (Picea sitchensis (Bong.) Carr.) currently recommended for use in British Columbia has poor extrapolation properties. Therefore, a new height-age model for Sitka spruce using stem analysis data collected from the Queen Charlotte Islands was developed. Care was taken to meet the standard regression assumptions. In particular, accounting for within-plot serial correlation improved the extrapolation abilities of the model by eliminating the crossing-over effect. The new model is being recommended for use in British Columbia because it offers better extrapolated height and site index estimates without sacrificing accuracy at young ages. Key words: Sitka spruce, site index, height-age model, serial correlation, nonlinear regression, extrapolation, model properties

scholarly journals A system for estimating height and site index of western hemlock in the interior of British Columbia

1998 ◽  
Vol 74 (4) ◽  
pp. 588-596 ◽  
Author(s):  
Gordon D. Nigh
Keyword(s):  
British Columbia ◽  
Site Index ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Index Model ◽  
Breast Height ◽  
Age Model ◽  
Site Index Model ◽  
Growth Intercept ◽  
Height Model

The focus of recent site productivity research in British Columbia has been to develop height-breast height age, growth intercept, and ecosystem-site index models. These models, together with a years-to-breast-height model, form a system for estimating site index and height. This system is described for western hemlock (Tsuga heterophylla (Raf.) Sarg.) in the interior of British Columbia. Forty-four western hemlock stem analysis plots were used in the construction of this system. As there are three models for estimating site index, the appropriate model for a given stand depends largely on the stand condition and the precision of the models. A graph of model precision against breast height age gives some assistance in deciding which model should be used to estimate site index. Key words: western hemlock, site index, height-age model, growth intercept model, years-to-breast-height model, ecosystem-site index model, model precision

STUDIES IN FOREST PATHOLOGY: VIII. DECAY OF WESTERN HEMLOCK ON THE QUEEN CHARLOTTE ISLANDS, BRITISH COLUMBIA

1951 ◽  
Vol 29 (5) ◽  
pp. 479-521 ◽  
Author(s):  
R. E. Foster ◽  
A. T. Foster
Keyword(s):  
British Columbia ◽  
Tsuga Heterophylla ◽  
Total Loss ◽  
Western Hemlock ◽  
Site Quality ◽  
Forest Pathology ◽  
Old Growth ◽  
Queen Charlotte Islands ◽  
Dead Trees ◽  
Understory Trees

An investigation of western hemlock (Tsuga heterophylla (Raf.) Sarg.) on the Queen Charlotte Islands, British Columbia, has shown that decay losses in old-growth stands are appreciable, amounting to 13.9, 8.0, and 10.7% of the gross volume of Grades 1, 2, and 3 logs respectively. Total loss, including dead trees, amounted to 25.5% of the gross volume. Twenty-seven decay-producing fungi have been isolated. The most important of these are Fomes pinicola (Sw.) Cke., F. pini (Thore) Lloyd, F. annosus (Fr.) Cke., and Polyporus sulphureus Bull. ex Fr. Echinodontium tinctorium E. & E. apparently does not occur in the region. Scars provided the most frequent, and roots the most important, avenue of entrance for decay. The logs of 2318 western hemlock were analyzed in detail. Decay was found to increase progressively with diameter, age, and decreasing site quality. Maximum net periodic increment was reached between 350 and 400 years of age and between 35 and 40 in. in diameter. Color of bark was found to provide an added indication of tree maturity. Understory trees were found to give a substantial yield of sound wood.

A New Species of Zeiraphera Treitschke From British Columbia (Lepidoptera: Tortricidae)

1966 ◽  
Vol 98 (6) ◽  
pp. 588-589
Author(s):  
T. N. Freeman
Keyword(s):  
British Columbia ◽  
New Species ◽  
Research Laboratory ◽  
Insect Pests ◽  
Sitka Spruce ◽  
Companion Paper ◽  
Forest Research ◽  
The Past ◽  
Queen Charlotte Islands ◽  
A New Species

During the past few years Mr. S. F. Condrashoff, Forest Research Laboratory, Canada Department of Forestry, Victoria, B.C., has been studying the insect pests of Sitka spruce on the Queen Charlotte Islands. One of these is a new species and the description of it is presented here to enable Mr. Condrashoff to describe the larva in a companion paper that follows (Can. Ent. 98: 703–706 (1966), in press).

Impact of feeding damage by the porcupine on western hemlock – Sitka spruce forests of north-coastal British Columbia: 15-year results

2003 ◽  
Vol 33 (10) ◽  
pp. 1983-1989 ◽  
Author(s):  
Alex J Woods ◽  
Stefan Zeglen
Keyword(s):  
British Columbia ◽  
Mixed Forest ◽  
Sitka Spruce ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Western Hemlock ◽  
North Coast ◽  
Feeding Damage ◽  
Decay Fungi ◽  
Dead Trees

American porcupine (Erithizon dorsatum L.) feed on the cambial tissues of several tree species. This study assessed feeding by porcupine over a 15-year period on midrotation age western hemlock (Tsuga heterophylla (Raf.) Sarg.) dominated stands on the north coast of British Columbia, Canada. Although four coniferous hosts were available, hemlock was, by far, the most preferred and most seriously impacted. Of 398 hemlock studied, 260 were wounded by porcupine feeding and 86 died by 2000. Porcupine attacked two-thirds of the dead trees, over 82% of which were dominant or codominant, while almost all unattacked dead trees were intermediate or suppressed. This loss resulted in a 14.6% reduction in the proportion of volume per hectare represented by hemlock and an increase in the representation by other species, all of which suffered little or no feeding damage. Results indicate that the final merchantable volume of hemlock expected at rotation age will be lower than projected and will consist mainly of damaged trees of poor form and quality due to decay fungi, such as Stereum sanguinolentum (A. & S. ex Fr.), entering through feeding wounds. Porcupine activity has led to a shift in species composition and volume from a condition where a single species, western hemlock, dominates to a mixed forest consisting of amabilis fir (Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes), Sitka spruce (Picea sitchensis (Bong.) Carrière), and western hemlock.

Seasonal Variation of Stump Infection by Fomes Annosus in Coastal British Columbia

1970 ◽  
Vol 46 (3) ◽  
pp. 200-202 ◽  
Author(s):  
D. J. Morrison ◽  
A. L. S. Johnson
Keyword(s):  
British Columbia ◽  
Seasonal Variation ◽  
Sitka Spruce ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Lower Percentage ◽  
Fresh Cut ◽  
Coastal British Columbia ◽  
Cut Stumps

Susceptibility of fresh-cut stumps of western hemlock, amabilis fir, Douglas-fir and Sitka spruce to infection via Fomes annosus (Fr.) Karst. spores was determined at 12 consecutive monthly intervals. Over 40% of the amabilis fir, western hemlock, Douglas-fir and Sitka spruce stumps became infected throughout the year when inoculated with a basidiospore suspension. Airborne spore infection of amabilis fir was high (> 80%) throughout the year; infection of Douglas-fir was lower during the summer, whereas infection of hemlock was lower during the fall and winter. Excepting amabilis fir, natural airborne spore inoculum resulted in a lower percentage stump infection than when the stumps were inoculated with basidiospores.

The Relation of Weather to Population Trends of the Black-headed Budworm Acleris variana (Fern.) (Lepidoptera: Tortricidae)

1960 ◽  
Vol 92 (6) ◽  
pp. 401-410 ◽  
Author(s):  
G. T. Silver
Keyword(s):  
British Columbia ◽  
West Coast ◽  
Vancouver Island ◽  
Tsuga Heterophylla ◽  
Population Trends ◽  
Western Hemlock ◽  
Canal Area ◽  
Queen Charlotte Islands ◽  
History Of ◽  
Coastal British Columbia

The history of the black-headed budworm, Acleris variana (Fern.), in the western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests of coastal British Columbia is one of recurring cycles of outbreaks. The latest cycle occurred from 1952 to 1957 and was represented by three main outbreaks in the Portland Canal area from Prince Rupert to Stewart, the Queen Charlotte Islands, and on northern Vancouver Island. Previous to this, groups of West Coast outbreaks were recorded from 1940 to 1945, and from 1927 to 1931 (Prebble and Graham, 1945a).

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