Western Redcedar Seed, a Food of Pine Siskins

The Murrelet ◽  
1966 ◽  
Vol 47 (3) ◽  
pp. 73
Author(s):  
Jay S. Gashwiler ◽  
A. Lorin Ward
Keyword(s):  
2018 ◽  
Vol 40 (3) ◽  
pp. 368-377 ◽  
Author(s):  
Michael G. Cruickshank ◽  
Cosmin N. Filipescu ◽  
Rona N. Sturrock

2015 ◽  
Vol 91 (04) ◽  
pp. 436-443 ◽  
Author(s):  
Verena C. Griess ◽  
Rajat Panwar ◽  
Julie Cool

Western redcedar (WRC) is a highly desirable species in British Columbia's Coastal Western Hemlock zone, both from a management and a conservation perspective. However, it is also highly palatable for ungulates. Existing countermeasures against browsing all have high costs and imperfect results in common. We used the portfolio method to display how diversification can help to lower investment risk. Using risk-return ratios of a WRC and Douglas-fir (DF), we derived species portfolios that yield maximum financial return per unit of risk. Financial indicators were calculated based on Monte Carlo simulations, which consider timber price fluctuation and browsing risk. Results show how economic risks of a forest investment could be reduced by creating a species portfolio. The optimum portfolio leading to most beneficial risk-return combination is 75% WRC and 25% DF if browsing is lowered using protective measures that double planting costs; and 30% WRC and 70% DF if no protective measures are applied. Accordingly, the most desirable risk-return combination is that of a mixed-species forest, whereas the 2 species don't have to be grown in intimate mixtures. Our research sketches a path forward that can help to ensure WRC will remain an important asset in BC's timber portfolio.


2001 ◽  
Vol 79 (6) ◽  
pp. 753-756 ◽  
Author(s):  
Lisa M. O'Connell ◽  
Frédérique Viard ◽  
John Russell ◽  
Kermit Ritland

2001 ◽  
Vol 31 (6) ◽  
pp. 978-987 ◽  
Author(s):  
J M Kranabetter ◽  
P Kroeger

We examined epigeous ectomycorrhizal mushroom richness and productivity after partial cutting in a western hemlock (Tsuga heterophylla (Raf.) Sarg.) - western redcedar (Thuja plicata Donn ex D. Don in Lamb.) forest of northwestern British Columbia. Mushrooms were collected throughout the fruiting season (July to October) for 3 years, starting 5 years after partial cutting, from plots with mesic soil conditions and residual basal areas ranging from 23 to 69 m2/ha for western hemlock and 0 to 26 m2/ha for western redcedar. Partial cutting had no apparent effect on mushroom phenology over the 3 years. Significant block interactions demonstrated that reductions in basal area of western hemlock could lead to positive, neutral, and negative responses in mushroom richness, biomass, and number of fruiting bodies. These responses were related to stand structure and the potential differences in tree vigour after partial cutting. In addition, there was weak evidence that western redcedar, a host for vesicular-arbuscular mycorrhiza, had a negative effect on average taxon richness. The study demonstrated that partial-cutting systems could allow some timber removal without necessarily reducing ectomycorrhizal mushroom communities.


2006 ◽  
Vol 36 (10) ◽  
pp. 2439-2453 ◽  
Author(s):  
Timothy B Harrington

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western redcedar (Thuja plicata Donn ex D. Don) seedlings were planted in March 2001 within three clearcut-harvested, shelterwood, or thinned stands of mature Douglas-fir near Olympia, Washington. From 2002 to 2005, areas of vegetation control of 0, 4.5, or 9 m2 were maintained with herbicides around a total 162 seedlings per species. Photosynthetically active radiation (PAR) was 34%, 62%, and 100% of full sunlight in thinned stands, shelterwoods, and clearcuts, respectively. Effects of overstory level and vegetation control on seedling growth and resource availability generally were additive. Seedling stem volume index in clearcuts averaged four to eight times that observed in thinned stands, and with vegetation control, it averaged two to four times that observed without it. In thinned stands, relative growth rate of seedling stem volume index had a positive linear relationship with PAR (R2 = 0.38). Foliar nitrogen content of Douglas-fir explained 71% of the variation in relative growth rate. Factors explaining the most variation in foliar nitrogen content differed between thinned stands (PAR, R2 = 0.34) and clearcuts or shelterwoods (midday water potential, R2 = 0.63), suggesting that light and root competition, respectively, were the primary growth-limiting factors for these overstory levels.


1980 ◽  
Vol 10 (2) ◽  
pp. 169-175 ◽  
Author(s):  
J. Harry G. Smith

Growth in ring width and percentage latewood on a very good site is described for 21-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), 20-year-old western hemlock (Tsugaheterophylla (Raf.) Sarg.), and western redcedar (Thujaplicata Donn) planted at five spacings (0.91 to 4.57 m). Cores extracted at breast height are used to show the effects of spacing through growth rate and crown development, and of age through number of rings from pith for the years 1965 to 1976. Percentages of latewood measured by binocular microscope are compared with results obtainable by X-ray methods for analysis of ring widths and densities. Influences of spacing on wood quality are discussed. It is concluded that wide initial spacings increase ring width and decrease percentage latewood significantly, but the reduced costs and increased sizes at wide spacings provide more than adequate compensation for the moderate reduction in wood quality.


Sign in / Sign up

Export Citation Format

Share Document