scholarly journals Mapping the environmental limitations to growth of coastal Douglas-fir stands on Vancouver Island, British Columbia

2007 ◽  
Vol 27 (6) ◽  
pp. 805-815 ◽  
Author(s):  
N. C. Coops ◽  
S. B. Coggins ◽  
W. A. Kurz
2000 ◽  
Vol 30 (4) ◽  
pp. 566-572 ◽  
Author(s):  
Fangliang He ◽  
Hugh J Barclay

The 27-year response of understory vegetation in a 51-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forest to thinning and N fertilization treatments was examined in a silviculture experiment at Shawnigan Lake on southern Vancouver Island of British Columbia. The experiment was a two-way factorial design with three levels for each of thinning and N fertilization. No significant treatment effects on the number of either vascular or nonvascular species were detected. This was also true for the covers of the majority of understory species except salal (Gaultheria shallon Pursh) and Oregon beaked moss (Kindbergia oregana (Sull.) Ochyra). Heavy thinning led to high salal and Oregon beaked moss cover, whereas heavy fertilization resulted in lower cover of salal but had no effect on the cover of Oregon beaked moss. Although thinning had a marginal effect on the cover of canopy trees 27 years after treatment, the cover of the canopy trees had only minimal effects on understory vegetation. Conversely, no adverse effect of understory vegetation on canopy trees was found. This study suggested that after 27 years thinning and fertilization had little effect on understory vegetation whether in terms of species richness or vegetation cover. An effective way to conserve species diversity is to protect specific substrate types, e.g., tree trunks, stumps, and coarse woody debris. A commercial thinning was recommended to reduce the time of stem exclusion in similar type of forests.


1950 ◽  
Vol 82 (4) ◽  
pp. 85-86 ◽  
Author(s):  
George A. Hardy

The following article contains two records apparently new to Vancouver Island, notes concerning two species rare in collections from the island and remarks concerning the status of Leptura soror LeConte.Holopleura murginata LeC. A single male, taken on Mount Tzouhalem, Duncan, Vancouver Island, on May 21, 1947, by R. L. Fiddick apparently provides the first record for the island. This interesting species was called to my attention by G. Stace Smith of Creston to whom it was originally sent for determination. The only other British Columbia record, published by H. B. Leech (1945) is based on a single specimen beaten from a Douglas fir at Arrowhead, B.C. by G. Slade on May 10, 1945.


1958 ◽  
Vol 90 (2) ◽  
pp. 65-80 ◽  
Author(s):  
G. T. Silver

The silver-spotted tiger moth, Halisidota argentata Pack., is a potentially dangerous defoliator of Douglas fir in British Columbia. Natural control factors have always prevented populations from building up to destructive proportions.The literature contains little information on this insect. Fletcher recorded the first outbreak of what was probably H. argentata in British Columbia in 1887 (2). Moths were identified as H. sobrina Stretch, but this form is now recorded only from California so it was probably H. argentata. The outbreak, probably on southern Vancouver Island, was reported as “committing great depredations on the spruces here.” Mathers found H. argentata at Chilliwack in the Fraser River Valley in 1934, but there was no report of an outbreak (4). A few larvae were collected on southern Vancouver Island from 1936 to 1952. In 1953 a considerable number of colonies were observed, and the following year the silver-spotted tiger moth was in infestation proportions. In 1955 the outbreak increased in intensity, and spread northward to the limit of its known range. A survey in the spring of 1956 failed to find a single colony south of Lantzville, and the population in the northern portion of the range was greatly reduced.


1992 ◽  
Vol 22 (11) ◽  
pp. 1646-1655 ◽  
Author(s):  
A.L. Roth ◽  
S.M. Berch

Ectomycorrhizal colonization of container-grown Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings was determined in a container nursery near Nanaimo, British Columbia, and after one growing season under a range of field conditions on eastern Vancouver Island. The percentage of Douglas-fir and western hemlock short roots colonized by ectomycorrhizal fungi in the nursery was highly variable, but over 99% of the ectomycorrhizae were formed by Thelephoraterrestris Ehrh.:Fr. Between 72 and 93% of the new roots were ectomycorrhizal after one field season, and Thelephoraterrestris remained the dominant fungus in most cases. Rhizopogonvinicolor like ectomycorrhizae were also common on new roots of Douglas-fir. Cenococcumgeophilum Fr. was less common. Douglas-fir seedlings formed 33 morphologically distinct ectomycorrhizae on eight sites within one growing season in the field. Western hemlock formed nine types on a single site.


2018 ◽  
Vol 603 ◽  
pp. 189-200 ◽  
Author(s):  
WD Halliday ◽  
MK Pine ◽  
APH Bose ◽  
S Balshine ◽  
F Juanes

1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.


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