Biological Factors Affecting Contarinia oregonensis (Diptera: Cecidomyiidae) Infestations in Douglas-Fir Seed Orchards on Vancouver Island, British Columbia

1984 ◽  
Vol 13 (3) ◽  
pp. 873-877 ◽  
Author(s):  
G. E. Miller
Keyword(s):  
British Columbia ◽  
Vancouver Island ◽  
Douglas Fir ◽  
Biological Factors ◽  
Seed Orchards ◽  
Factors Affecting

Some aspects of the vegetation ecology of the Nanoose–Bonell estuary, Vancouver Island, British Columbia

1986 ◽  
Vol 64 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Neil K. Dawe ◽  
Eric R. White
Keyword(s):  
British Columbia ◽  
Vascular Plants ◽  
Dry Weight ◽  
Vancouver Island ◽  
Distichlis Spicata ◽  
Factors Affecting ◽  
Salicornia Virginica ◽  
Major Factors ◽  
Triglochin Maritimum ◽  
Water Elevation

A study of the vegetation of the Nanoose – Bonell salt marsh, Vancouver Island, British Columbia, was conducted during the period of May – September 1978. A total of 49 species of vascular plants was identified, 10 of which dominated the flora of the estuarine marsh. Six of those dominant species (Distichlis spicata, Glaux maritima, Salicornia virginica, Triglochin maritimum, Plantago maritima, and Atriplex patula) are tolerant of high salinities. Eight plant communities were identified and mapped within the study area. Aerial biomass was dominated by that of the Carex – channel edge community with a peak aboveground biomass of 1259 g dry weight/m2. Major factors affecting the occurrence and distribution of species within the marsh were salinity of the inundating water, elevation of the marsh platform, and soil texture.

Estimation of seed orchard efficiencies by means of multistage variable probability sampling

1988 ◽  
Vol 18 (11) ◽  
pp. 1397-1404 ◽  
Author(s):  
C. Bartram ◽  
G. Miller
Keyword(s):  
British Columbia ◽  
Sampling Methods ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Alternative Methods ◽  
Seed Orchards ◽  
Probability Sampling ◽  
Variable Probability Sampling ◽  
Efficiency Data ◽  
Variable Probability

This paper describes two frameworks for developing effective multistage variable probability sampling methods to estimate seed orchard efficiencies. In both cases a standard multistage approach is implemented initially in multiple orchards and years. The effectiveness of this approach is then evaluated against several alternative methods, using the initial efficiency data collected, and subsequent survey procedures are prescribed on the basis of this analysis. An example illustrating the application of this methodology in coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seed orchards in British Columbia is presented.

DISTRIBUTION AND IMPACT OF LEPTOGLOSSUS OCCIDENTALS HEIDEMANN (HEMIPTERA: COREIDAE) IN SEED ORCHARDS IN BRITISH COLUMBIA

1996 ◽  
Vol 128 (6) ◽  
pp. 1065-1076 ◽  
Author(s):  
Suzie E. Blatt ◽  
John H. Borden
Keyword(s):  
British Columbia ◽  
Seed Production ◽  
Pseudotsuga Menziesii ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Douglas Fir ◽  
Seed Orchards ◽  
Threshold Levels ◽  
Management Measures ◽  
Leptoglossus Occidentalis

AbstractLeptoglossus occidentalis Heidemann (Hemiptera: Coreidae) is considered to be an important cone and seed pest in seed orchards in British Columbia; however, no impact studies have been done in Canada. Surveys to determine the distribution of L. occidentalis were conducted over a 3-year period in three coastal seed orchards of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, and over a 2-year period in two seed orchards of lodgepole pine, Pinus contorta var. latifolia Engelmann. Leptoglossus occidentalis was found to distribute itself in patches, coinciding with a clonal preference. Seed losses were assessed for 2 years in the coastal Douglas-fir orchards and for 1 year in one lodgepole pine orchard. The percentages of partially filled seed that could have been caused by feeding of L. occidentalis or by a number of other factors were < 5% in coastal Douglas-fir for both 1992 and 1993 and ~14% in lodgepole pine in 1993. Apparently because populations of L. occidentalis were low, there was no correlation between the percentage of partially filled seed and number of insects per tree. Except in unusual circumstances, management measures in Canada are judged not to be necessary as populations of L. occidentalis are consistently below the calculated threshold levels required to cause ≥5% loss in seed production.

scholarly journals The Development of a Program for the Genetic Improvement of Douglas-fir in British Columbia

1969 ◽  
Vol 45 (6) ◽  
pp. 395-399 ◽  
Author(s):  
A. L. Orr-Ewing
Keyword(s):  
British Columbia ◽  
Seed Production ◽  
Genetic Improvement ◽  
Service Industry ◽  
Douglas Fir ◽  
Important Species ◽  
Seed Orchards ◽  
Seed Sources ◽  
Interim Measure ◽  
Production Areas

The Douglas-fir, one of the most important species in western North America, has been widely planted in coastal British Columbia since 1930. The present measures being taken by the British Columbia Forest Service, Industry and the University of British Columbia to improve the genetic quality of the large amounts of seed required, are discussed. These include seed production areas, selections of plus trees in clone banks and seed orchards, together with the research programs being undertaken by all three organizations. It is noted that at the present time more than 90 per cent of the Douglas-fir seed is collected from unimproved stands. It is considered that the acreage of the seed production areas and the planned expansion of seed orchards will not be sufficient to ensure that future collections will be from improved seed sources. An immediate expansion of seed production areas is suggested as an interim measure. It is considered that there is great potential for the genetic improvement of Douglas-fir as it has already been demonstrated that the species is adaptable to radically different methods of breeding.

Long-term response of understory plant species to thinning and fertilization in a Douglas-fir plantation on southern Vancouver Island, British Columbia

2000 ◽  
Vol 30 (4) ◽  
pp. 566-572 ◽  
Author(s):  
Fangliang He ◽  
Hugh J Barclay
Keyword(s):  
British Columbia ◽  
Vancouver Island ◽  
N Fertilization ◽  
Douglas Fir ◽  
Understory Vegetation ◽  
Marginal Effect ◽  
Specific Substrate ◽  
Significant Treatment ◽  
Commercial Thinning ◽  
Canopy Trees

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.

Notes on, and Additions to the Cerambycidae of Vancouver Island

1950 ◽  
Vol 82 (4) ◽  
pp. 85-86 ◽  
Author(s):  
George A. Hardy
Keyword(s):  
British Columbia ◽  
First Record ◽  
Vancouver Island ◽  
Douglas Fir ◽  
Single Specimen ◽  
Single Male ◽  
The Status ◽  
Interesting Species

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.

Studies on the Silver-spotted Tiger Moth, Halisidota argentata Pack. (Lepidoptera: Arctiidae), in British Columbia

1958 ◽  
Vol 90 (2) ◽  
pp. 65-80 ◽  
Author(s):  
G. T. Silver
Keyword(s):  
British Columbia ◽  
Vancouver Island ◽  
Douglas Fir ◽  
River Valley ◽  
Fraser River ◽  
Natural Control ◽  
Control Factors ◽  
Single Colony ◽  
Tiger Moth ◽  
Northern Portion

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.

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