Surface pollen spectra from southern Vancouver Island, British Columbia, Canada

1999 ◽  
Vol 77 (6) ◽  
pp. 786-799 ◽  
Author(s):  
Gregory B Allen ◽  
Kendrick J Brown ◽  
Richard J Hebda
Keyword(s):  
Pseudotsuga Menziesii ◽  
Vancouver Island ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Mean Annual Precipitation ◽  
Vegetation Types ◽  
Quercus Garryana ◽  
Surface Samples ◽  
Proxy Measure ◽  
Pollen And Spores

Analyses of surface samples of 84 sites from southern Vancouver Island were used to characterize pollen and spore spectra of modern vegetation types. Xeric Quercus garryana Dougl. and grassland associations can be identified by Quercus pollen and abundant nonarboreal pollen, respectively. Coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) forests are distinguished by high proportions of Pseudotsuga and low Pseudotsuga to Tsuga heterophylla (Raf.) Sarg. ratios. Coastal Western Hemlock zone forests have abundant Tsuga heterophylla pollen. Dry Coastal Western Hemlock subzones have diagnostically abundant Pseudotsuga and Tsuga heterophylla pollen, and intermediate Pseudotsuga to Tsuga heterophylla ratios. Moist Coastal Western Hemlock variants are characterised by little or no Pseudotsuga pollen and high Pseudotsuga to Tsuga heterophylla ratios. The Mountain Hemlock zone exhibits abundant Tsuga mertensiana (Bong.) Carr. pollen percentages and notable nonarboreal pollen and spore values. Relatively high Alnus values are not necessarily indicators of dominant alder stands, especially when obtained from open communities. Pseudotsuga to Tsuga heterophylla ratios are useful as a proxy measure of mean annual precipitation between 700 and 2700 mm.Key words: pollen and spores, surface spectra, Vancouver Island, biogeoclimatic zone, vegetation, precipitation.

Survival dynamics of mechanically topped Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) snags in Douglas-fir plantations, Oregon, USA

2019 ◽  
Vol 433 ◽  
pp. 105-110
Author(s):  
Matthew E. Hane ◽  
Andrew J. Kroll ◽  
Aaron Springford ◽  
Jack Giovanini ◽  
Mike Rochelle ◽  
...  
Keyword(s):  
Pseudotsuga Menziesii ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock

Effects of genetic selection for growth on frost hardiness in western hemlock

1999 ◽  
Vol 29 (4) ◽  
pp. 509-516 ◽  
Author(s):  
Mats Hannerz ◽  
Sally N Aitken ◽  
John N King ◽  
Sonya Budge
Keyword(s):  
Genetic Gain ◽  
Genetic Selection ◽  
Seed Orchard ◽  
Vancouver Island ◽  
Tsuga Heterophylla ◽  
Frost Hardiness ◽  
Western Hemlock ◽  
Spring Frost ◽  
Queen Charlotte Islands ◽  
Sib Families

Fall and spring frost hardiness was determined from electrolytic leakage of artificially frozen needle segments in 22 full-sib families of western hemlock (Tsuga heterophylla (Raf.) Sarg.) from British Columbia and Washington State representing different levels of genetic gain, and of four provenance materials (stand progenies from the Queen Charlotte Islands, Vancouver Island, and Oregon Cascades, and seed-orchard progenies from the northern Oregon Coast Range). Samples for freeze testing were collected in a 5-year-old trial at Jordan River on southwestern Vancouver Island. Height and date of bud flush were recorded in the field. Genetic gain among the full-sib families was not correlated with fall frost hardiness, but high-yielding families displayed a lower spring frost hardiness and an earlier bud flush than low-yielding families. Both fall and spring frost hardiness increased and height growth decreased with the latitude of provenances. The highest growth, earliest bud flush and lowest fall and spring frost hardiness was demonstrated by the Oregon provenances, while the lowest growth, latest bud flush and highest hardiness was found for the Queen Charlotte Islands provenance.

Diaporthe lokoyae n. sp., the perfect state of Phomopsis lokoyae

1968 ◽  
Vol 46 (5) ◽  
pp. 601-603 ◽  
Author(s):  
A. Funk
Keyword(s):  
New Species ◽  
Pseudotsuga Menziesii ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Perfect State ◽  
Ascigerous State ◽  
A New Species

A new species of Diaporthe, for which the name D. lokoyae Funk is proposed, is described on the host Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and in culture. This Diaporthe is shown to be the ascigerous state of Phomopsis lokoyae Hahn. An outbreak of dieback in Douglas fir associated with this Diaporthe is described and discussed; a single occurrence on western hemlock (Tsuga heterophylla (Raf.) Sarg.) is reported.

Origin, development, and dynamics of coastal temperate conifer rainforests of southern Vancouver Island, Canada

2002 ◽  
Vol 32 (2) ◽  
pp. 353-372 ◽  
Author(s):  
K J Brown ◽  
R J Hebda
Keyword(s):  
Late Glacial ◽  
Vancouver Island ◽  
Tsuga Heterophylla ◽  
Fire Disturbance ◽  
Thuja Plicata ◽  
Quercus Garryana ◽  
Mixed Conifer Forests ◽  
Forested Ecosystems ◽  
Increasing Precipitation ◽  
Early Late

Pollen and charcoal from East Sooke Fen, Pixie Lake, and Whyac Lake were used to reconstruct the post glacial vegetation, climate, and fire-disturbance history across a precipitation gradient on southern Vancouver Island, British Columbia. An open Pinus woodland covered the landscape in the early late-glacial interval. Fires were absent under a cool and dry climate. Closed mixed conifer forests of Pinus, Picea, Abies, Tsuga heterophylla (Raf.) Sarg., and Tsuga mertensiana (Bong.) Carrière replaced the Pinus biogeochron in the late late-glacial interval. Fires became more common even though climate was cool and moist. Open Pseudotsuga menziesii (Mirb.) Franco forests expanded westward during the warm dry early Holocene, though closed Picea and Tsuga heterophylla forests grew in the wettest part of the area at Whyac Lake. Modern precipitation gradients likely originated at this time. Fires occurred in forested ecosystems, although East Sooke Fen at the driest end of the gradient experienced less fire. The middle and late Holocene was characterized by increasing precipitation and decreasing temperature, respectively. Quercus garryana Dougl. stands spread westward during the mid-Holocene. Extant closed Tsuga heterophylla and Cupressaceae (Thuja plicata Donn. ex D. Don) forests arose in the wetter part of the gradient, whereas Pseudotsuga forests occupied drier eastern areas. During this interval, fires were rare in wet western regions but apparently more common in dry eastern regions.

Multi-decadal establishment for single-cohort Douglas-fir forests

2014 ◽  
Vol 44 (9) ◽  
pp. 1068-1078 ◽  
Author(s):  
James A. Freund ◽  
Jerry F. Franklin ◽  
Andrew J. Larson ◽  
James A. Lutz
Keyword(s):  
Pseudotsuga Menziesii ◽  
Temporal Patterns ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
Old Growth Forests ◽  
Western Washington ◽  
Century Development ◽  
Single Cohort

The rate at which trees regenerate following stand-replacing wildfire is an important but poorly understood process in the multi-century development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests. Temporal patterns of Douglas-fir establishment reconstructed from old-growth forests (>450 year) have generated contradictory models of either rapid (<25 year) or prolonged (>100 year) periods of establishment, while patterns of tree establishment in mid-aged (100 to 350 year) forests remains largely unknown. To determine temporal patterns of Douglas-fir establishment following stand-replacing fire, increment cores were obtained from 1455 trees in 18 mature and early old-growth forests in western Washington and northwestern Oregon, USA. Each of the stands showed continuous regeneration of Douglas-fir for many decades following initiating fire. The establishment period averaged 60 years (range: 32–99 years). These results contrast both with the view of rapid (one- to two-decade) regeneration of Douglas-fir promoted in the early forestry literature and with reports of establishment periods exceeding 100 years in older (>400 year) Douglas-fir–western hemlock stands. These results have important implications for management designed to create and promote early-seral forest characteristics.

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).

REPRODUCTION AND SURVIVAL OF THE AMBROSIA BEETLE TRYPODENDRON LINEATUM (OLIV.) (COLEOPTERA: SCOLYTIDAE) IN DOUGLAS-FIR AND WESTERN HEMLOCK LOGS

1987 ◽  
Vol 119 (2) ◽  
pp. 131-139 ◽  
Author(s):  
T.L. Shore ◽  
J.A. McLean ◽  
J.C. Zanuncio
Keyword(s):  
Sex Ratio ◽  
Pseudotsuga Menziesii ◽  
Pupal Stage ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Flight Period ◽  
Trypodendron Lineatum ◽  
Brood Production ◽  
Linear Relationships

AbstractSpring-felled logs of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, and western hemlock, Tsuga heterophylla (Raf.) Sarg., were attacked by ambrosia beetles, Trypodendron lineatum (Oliv.), in the year after felling. By monitoring individual galleries it was determined that brood production was similar to that found in fall- and winter-felled logs. The sex ratio of the brood did not differ significantly from 1:1. Only beetles that had failed to establish successful galleries emerged during the "second" flight period. Significant linear relationships were found between frass weight and each of the following variables: number of egg niches, emerged adult progeny, and gallery length. Mortality in galleries in Douglas-fir and western hemlock logs, respectively, was found to be 9.4 and 12.4% between the egg and larval–pupal stage and 19.5 and 32.1% between the larval–pupal and adult stages.

Crown profile equations for stand-grown western hemlock trees in northwestern Oregon

2003 ◽  
Vol 33 (11) ◽  
pp. 2059-2066 ◽  
Author(s):  
David D Marshall ◽  
Gregory P Johnson ◽  
David W Hann
Keyword(s):  
Pseudotsuga Menziesii ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Lower Portion ◽  
Data Set ◽  
Profile Model ◽  
Crown Width ◽  
Crown Form

Crown profile equations were developed for stand-grown western hemlock (Tsuga heterophylla (Raf.) Sarg.) in northwest Oregon. The profile model uses a segmented approach, dividing the crown into an upper and lower portion at the point of the largest crown width (LCW). The model explains about 86% of the variation in crown width when LCW is known but only 66% when LCW is predicted using a model developed from a larger data set collected in the same area as the data for developing the crown profile models were collected. The model can be adjusted using measurements or predictions of LCW for western hemlock in other populations. Comparisons are made with the crown form of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco).

A new Nitschkia on western conifers and its probable microconidial state

1979 ◽  
Vol 57 (20) ◽  
pp. 2113-2115 ◽  
Author(s):  
A. Funk
Keyword(s):  
British Columbia ◽  
New Species ◽  
Pseudotsuga Menziesii ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Coastal British Columbia ◽  
A New Species

A new species, Nitschkia molnarii (Ascomycetes: Nitschkiaceae), is described from Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) in coastal British Columbia, Canada. A microconidial state closely associated with the ascocarps is described, but not separately named.

A New Species of the Genus Cinara Curtis (Homoptera: Aphididae) from Tsuga heterophylla (Raf.) Sarg

1960 ◽  
Vol 92 (8) ◽  
pp. 605-608 ◽  
Author(s):  
G. A. Bradley
Keyword(s):  
British Columbia ◽  
New Species ◽  
Vancouver Island ◽  
Tsuga Heterophylla ◽  
The Body ◽  
Western Hemlock ◽  
A New Species ◽  
Made In

Aphids of the species described below were first seen by the author at Cowichan Lake, Vancouver Island, in 1956. Additional observations and collections were made in 1959 at several other locations in southern British Columbia.The species is unique in that it is apparently the only one in the genus living on western hemlock, Tsuga heterophylla (Raf.) Sarg.All measurements of the body and appendages are in millimetres.

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