Slow growth, long-lived trees, and minimal disturbance characterize the dynamics of an ancient, montane forest in coastal British Columbia

2006 ◽  
Vol 36 (11) ◽  
pp. 2826-2838 ◽  
Author(s):  
Roberta Parish ◽  
Joseph A Antos
Keyword(s):  
British Columbia ◽  
Tree Species ◽  
Vegetative Reproduction ◽  
Tsuga Heterophylla ◽  
Growth Patterns ◽  
Small Scale ◽  
Seedling Bank ◽  
History Of ◽  
Coastal British Columbia ◽  
Level Disturbance

Elucidating the factors that structure very old forests is crucial to understanding their dynamics. We reconstructed the history of an ancient (1000-year-old) stand in the mountains of coastal British Columbia that contained four tree species (Abies amabilis (Dougl.) Forbes, Chamaecyparis nootkatensis (D. Don) Spach., Tsuga mertensiana (Bong.) Carr., and Tsuga heterophylla (Raf.) Sarg.) in the canopy and the seedling bank. Using dendrochronological procedures, we examined the growth patterns of all trees (>4.0 cm diameter at breast height) in four 0.25 ha mapped plots. We also sampled the seedling bank in the four plots. Age structures indicated variable but rather continuous recruitment for all species. Periods of increased amounts of release or rapid early growth occurred but were not pronounced. Overall, we found little evidence for stand-level disturbance or the formation of large gaps. All four tree species appear able to persist in the stand in the absence of major stand-level disturbance, but the mechanisms contributing to coexistence differ. One species, C. nootkatensis, depends primarily on vegetative reproduction for persistence. Single-tree gap dynamics have predominated in the stand for centuries, placing this stand at the far end of the gradient from forests controlled by large, severe disturbances to those where very small-scale processes predominate.

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).

Forest reproduction methods for coastal British Columbia: Principles, criteria, and a stand selection guide

1994 ◽  
Vol 70 (5) ◽  
pp. 569-577 ◽  
Author(s):  
K. Klinka ◽  
G. J. Kayahara ◽  
R. E. Carter
Keyword(s):  
British Columbia ◽  
Tree Species ◽  
Stand Structure ◽  
Species Selection ◽  
Cutting Method ◽  
Management Objectives ◽  
Dichotomous Key ◽  
Management Factors ◽  
Reproduction Method ◽  
Coastal British Columbia

Once a decision to regenerate a particular stand is made at the forest level, a forester has to make critical decisions at the stand level as to the choice of cutting method for existing stands to regenerate the desired species and develop a stand of the desired structure. Two related critical decisions in stand-level forest management are (1) selecting the best tree species to regenerate on a given site, and (2) selecting the appropriate method of cutting existing stands for both the regeneration of the desired species within a certain time and for maintaining or developing the desired stand structure. This paper discusses the management factors and principles and criteria for choosing a cutting method to meet decision (2) (i.e., the reproduction method). The four criteria used to guide the appropriate reproduction method are (1) maximum sustainable forest productivity, (2) stand reliability, (3) silvicultural feasibility, and (4) harvesting feasibility. With these criteria in mind, a stand-level guide devised for coastal British Columbia is proposed. This guide is in the form of a dichotomous key and is based on 13 selected ecological, stand, and management factors. Combining this approach with principles, criteria and guidelines for tree species selection already practiced, regeneration and management objectives can be achieved both on a species-and site-specific basis. Key words: forest reproduction methods, decision support systems, silvicultural prescriptions, harvesting methods, stand regeneration, stand structure

scholarly journals Estimating the Number of Filled Seeds per Cone of Western Hemlock from Coastal British Columbia

1996 ◽  
Vol 11 (2) ◽  
pp. 44-49
Author(s):  
M. D. Meagher
Keyword(s):  
British Columbia ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Linear Relationships ◽  
The Face ◽  
Predetermined Level ◽  
Exponential Factors ◽  
The Relationship ◽  
Coastal British Columbia ◽  
Filled Seeds

Abstract Unopened western hemlock (Tsuga heterophylla) cones from coastal British Columbia were tested for the relationship between total filled seeds per cone and the number of sound seeds exposed by slicing through the center of the cone's long axis, and with cone length. Predictive linear relationships of total number of filled seeds per cone (TFS), based on number of filled seeds cut on the face through the cone's long axis (CC), were found in a cone sample bulked from a number of trees. The regression based on CC explained about 63% of the variation in TFS. More accurate estimates of TFS were found where cone length, and exponential factors of CC and cone length, were included in the analysis. Analyses of cones from seven parents did not find statistically significant trends of TFS on CC in all cases, and differed in slope in most cases. Sample sizes (cones) to estimate TFS to a predetermined level of precision were much larger than cones needed to accept or reject a tree for study. West. J. Appl. For. (11)2:44-49.

scholarly journals Foraging behaviour by gray wolves on salmon streams in coastal British Columbia

2003 ◽  
Vol 81 (2) ◽  
pp. 349-353 ◽  
Author(s):  
C T Darimont ◽  
T E Reimchen ◽  
P C Paquet
Keyword(s):  
British Columbia ◽  
Foraging Behaviour ◽  
Foraging Ecology ◽  
Capture Rate ◽  
Indirect Evidence ◽  
Terrestrial Ecosystems ◽  
Gray Wolves ◽  
History Of ◽  
The Relationship ◽  
Coastal British Columbia

Spawning salmon (Oncorhynchus spp.) are important resources for terrestrial ecosystems and often shape the ecological strategies of organisms with which they co-evolve. Gray wolves (Canis lupus), primarily predators of ungulates, are sympatric with salmon over large areas, but the relationship between the two remains poorly understood. We report here observations of direct and indirect evidence of salmon predation by wolves in several watersheds of coastal British Columbia and in detail report on the foraging behaviour of four wolves at one river during September and October 2001. Wolves oriented themselves upstream during detection and pursuit of salmon. The pooled mean capture rate was 21.5 salmon/h and mean efficiency (successes/attempt) was 39.4%. In most cases, wolves consumed only heads of salmon, perhaps for nutritional reasons or parasite avoidance. Preying on salmon may be adaptive, as this nutritious and spatially constrained resource imposes lower risks of injury compared with hunting large mammals. We infer from capture rates and efficiencies, as well as stereotypical hunting and feeding behaviour, a history of salmon predation by wolves and, as a corollary, a broad distribution of this foraging ecology where wolves and salmon still co-exist.

Olympia Interstadial: vegetation, landscape history, and paleoclimatic implications of a mid-Wisconsinan (MIS3) nonglacial sequence from southwest British Columbia, Canada

2016 ◽  
Vol 53 (3) ◽  
pp. 304-320 ◽  
Author(s):  
Richard J. Hebda ◽  
Olav B. Lian ◽  
Stephen R. Hicock
Keyword(s):  
British Columbia ◽  
Tsuga Heterophylla ◽  
Silty Sand ◽  
Western North America ◽  
Climate History ◽  
Southern Limit ◽  
Vegetation Landscape ◽  
History Of ◽  
Cordilleran Ice Sheet ◽  
Vegetation And Climate

Lithostratigraphic, 14C, and palynologic analyses of peat and silty peat at three nearby sites reveal a 25 000 year vegetation and climate history of the Olympia Interstade for the Fraser Lowland, British Columbia, 300 km within the southern limit of the Cordilleran Ice Sheet. At Lynn Valley, Polypodiaceae fern spores and nonarboreal pollen dominate >47.8 14C ka BP, reflecting unstable and cold landscapes. A Pinus–Poaceae zone follows, representing pine parkland and cool dry climate. Fluctuating values of Picea and Tsuga mertensiana pollen at Lynn and Seymour valleys and Port Moody characterize most of the Olympia Interstade during local peat deposition in Cyperaceae and Myrica wetlands until about 26.7 14C ka BP under a cool and moist climate. A brief Pinus – Tsuga heterophylla zone at Lynn Valley 44–39 14C ka BP suggests a climatic optimum. A Poaceae–Artemisia assemblage and deposition of silty sand after 26.7 14C ka BP reflect cooling and drying after which a unique Lycopodium assemblage at Lynn Valley suggests cold arid climate and Fraser Glaciation onset. These sequences have no progression to vegetation typical of warm, interglacial, Holocene-like climates, indicating an interstadial not an interglacial interval. Correlation with vegetation changes elsewhere in western North America suggests that the Olympia Interstade started about ∼52 14C ka BP (∼57 cal ka BP) and ended about 26 14C ka BP (30 cal ka BP).

Overturning resistance of western redcedar and western hemlock in mixed-species stands in coastal British Columbia

2007 ◽  
Vol 37 (5) ◽  
pp. 931-939 ◽  
Author(s):  
Kenneth E. Byrne ◽  
Stephen J. Mitchell
Keyword(s):  
British Columbia ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Specific Information ◽  
Mixed Species ◽  
Stem Form ◽  
Western Redcedar ◽  
Applied Forces ◽  
Coastal British Columbia

Specific information about the applied forces that cause trees to fail is required to validate mechanistic models of windthrow in different forest types. Static tree-pulling tests were conducted to examine the overturning resistance of western redcedar ( Thuja plicata Donn ex D. Don) and western hemlock ( Tsuga heterophylla (Raf.) Sarg.) in a mixed species second-growth stand in coastal British Columbia. Although widely used, tree-pulling techniques are not standardized. Data from three inclinometers were used to estimate stem deflection, which was found to increase with tree slenderness. Differing methods of fitting stem curvature had a small effect on estimates of self-loading at failure. The distance of the pivot point from the centre of the stem base increased with tree diameter. Accounting for the correct self-loading at failure produced a small difference in the overall turning moment regressions but did not improve the fit of these regressions. However, this difference increased with tree size and warrants consideration in future tree-pulling tests with large or plate-rooted trees. The stem mass – overturning resistance relationship had the best fit and was not significantly different for these species in spite of their differences in wood density and stem form.

Vanterpoolia, a new genus of sporodochial hyphomycetes

1982 ◽  
Vol 60 (6) ◽  
pp. 973-975 ◽  
Author(s):  
A. Funk
Keyword(s):  
British Columbia ◽  
New Genus ◽  
Single Species ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Coastal British Columbia

Vanterpoolia, a new genus of sporodochial hyphomycetes, is erected for a fungus occurring on necrotic, newly flushed needles of western hemlock (Tsuga heterophylla (Raf.) Sarg.) in coastal British Columbia, Canada. The genus is characterized by triradiate conidia or rodlike, appendaged conidia produced in acropetal chains from simple, septate conidiophores arising from a pseudoparenchymatous stroma. A single species, Vanterpoolia tsugae n.sp., is described.

Taxonomic Studies on the Acleris gloverana-variana Complex, the Black-headed Budworms (Lepidoptera: Tortricidae)

1962 ◽  
Vol 94 (8) ◽  
pp. 833-840 ◽  
Author(s):  
Jerry A. Powell
Keyword(s):  
British Columbia ◽  
Abies Balsamea ◽  
Tsuga Heterophylla ◽  
Northern Forest ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Important Host ◽  
Northern United States ◽  
Taxonomic Studies ◽  
Coastal British Columbia

The black-headed budworm has long been known as an endemic resident and occasional epidemic defoliator of coniferous forests in Canada and parts of northern United States. The moth is distributed across the whole of the northern forest area from Cape Breton Island to the west coast of Canada and Alaska. It is a serious and recurrent defoliator particularly in British Columbia and Washington (Silver, 1960). The larvae feed on various conifers of the genera Abies, Larix, Picea, Pseudotsuga, and Tsuga, and different hosts are preferred in different parts of the range. Thus, Schaffner (1950) gives Abies balsamea as the most important host in eastern areas, Raizenne (1952) indicates that species of spruce (Picea) are most often utilized in southern Ontario, while Tsuga heterophylla has been found to be preferred in coastal British Columbia (Leech, 1933; Keen, 1952; Evans and Silver, 1954; Silver, 1960).

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