Canker of Dwarf Mistletoe Swellings on Western Hemlock Caused by Nectriafuckeliana var. macrospora

1973 ◽  
Vol 3 (1) ◽  
pp. 71-74 ◽  
Author(s):  
A. Funk ◽  
R. B. Smith ◽  
J. A. Baranyay
Keyword(s):  
British Columbia ◽  
Western Hemlock ◽  
Artificial Inoculation ◽  
Dwarf Mistletoe

Nectriafuckeliana Booth var. macrospora (Wr.) Booth was commonly associated with open, resinous cankers of dwarf mistletoe swellings of western hemlock (Tsugaheterophylla (Raf.) Sarg.) in British Columbia, Canada. Pathogenicity of the fungus was proved by artificial inoculation and reisolation from cankered tissues. Cankers substantially reduced dwarf mistletoe reproduction.

Field evaluation of ecological differentiation of dwarf mistletoe on shore pine and western hemlock

1976 ◽  
Vol 6 (2) ◽  
pp. 225-228 ◽  
Author(s):  
R. B. Smith ◽  
E. F. Wass
Keyword(s):  
British Columbia ◽  
Field Evaluation ◽  
Field Studies ◽  
Western Hemlock ◽  
Lake Area ◽  
Dwarf Mistletoe ◽  
Varied Composition ◽  
Coastal British Columbia ◽  
Ecological Races ◽  
Shore Pine

Hemloclc dwarf mistletoe (Arcenthobiiuntsugense (Rosend.) G. N. Jones) principally infects western hemlock (Tsugaheteropliylla (Raf.) Sarg.), but it is also damaging to shore pine (Pinuscontorta Dougl. ex Loud.) growing in coastal British Columbia. Stands of varied composition were studied in the Home Lake area of Vancouver Island to compare the levels of infection in shore pine and western hemlock. Infection of shore pine occurred whether or not infected hemlock trees were present in the stand. Observations and measurements from these field studies support indications from earlier artificial inoculation trials that two ecological races of A. tsugense exist.

Development of dwarf mistletoe in western hemlock regeneration in southeast Alaska

1982 ◽  
Vol 12 (3) ◽  
pp. 482-488 ◽  
Author(s):  
Charles G. Shaw III
Keyword(s):  
British Columbia ◽  
Disease Control ◽  
Control Strategies ◽  
Severe Infection ◽  
Host Tissue ◽  
Western Hemlock ◽  
Dwarf Mistletoe ◽  
Local Conditions ◽  
Southeast Alaska ◽  
Understory Trees

Western hemlock (Tsugaheterophylla (Raf.) Sarg.) regenerated within 9.14 m of old-growth hemlock severely infected with dwarf mistletoe, Arceuthobiumtsugense ((Rosendahl) G.N. Jones), and left standing on cutover sites in southeast Alaska were felled and examined for infection. The percentage of understory trees infected among the 3429 examined averaged 9, 7, 5, and 17, respectively, in 17-, 19-, 35-, and 43-year-old stands. Ninety-two percent of all infections in the 17-, 19-, and 35-year-old stands were alive, but only 51% were alive in the 43-year-old stand. In all stands few trees had more than two live infections and few had any infections in their middle or upper crown. In all stands, advanced regeneration was more frequently infected and accounted for a significantly greater proportion of crop trees than new reproduction. A significantly higher proportion of hemlock crop trees were infected than non crop trees, but the number of infections on crop trees was consistently low. Most infections were established on host tissue 5 years or younger, but tissue up to 13 years old was infected. At a comparable age, young stands in Alaska appear to be less severely affected by A. tsugense than similar stands in Washington, Oregon, and British Columbia. Disease control strategies, developed for stands experiencing more severe infection intensities than those now known to prevail in southeast Alaska, will require modification to meet local conditions.

The Rate of Upward Advance and Intensification of Dwarf Mistletoe on Immature Western Hemlock

1972 ◽  
Vol 2 (3) ◽  
pp. 313-316 ◽  
Author(s):  
K. S. Richardson ◽  
B. J. van der Kamp
Keyword(s):  
British Columbia ◽  
Height Growth ◽  
Western Hemlock ◽  
Dwarf Mistletoe ◽  
Rate Of Spread ◽  
History Of ◽  
Dense Stand ◽  
Individual Trees ◽  
Crown Closure

The rate of upward advance and intensification of dwarf mistletoe on immature coastal western hemlock were determined by reconstructing the infection history of individual trees from data on age, height above ground, and sex of mistletoe infections present at the time of observation. The vertical rate of spread was 30 ± 4 cm/year in a dense stand (750 trees per hectare, 19 m in height) and 65 ± 4 cm/year in an open stand (250 trees per hectare, 26 m in height). This compares with height growth of the trees of 33 and 58 cm/year in the two stands, respectively. The number of new infections per year increased logarithmically with time, doubling roughly every 4 years. An asymtotic stabilization of the rate of intensification over the last 6 years probably reflects crown closure. The results suggest that dwarf mistletoe may not be a serious threat to thrifty, immature, dense, coastal hemlock stands in southern British Columbia, unless such stands are overtopped by infected residual trees.

Epidemiology of dwarf mistletoe in western hemlock stands in south coastal British Columbia

1985 ◽  
Vol 15 (5) ◽  
pp. 909-913 ◽  
Author(s):  
R. I. Alfaro ◽  
W. J. Bloomberg ◽  
R. B. Smith ◽  
A. J. Thomson
Keyword(s):  
British Columbia ◽  
Spatial Distribution ◽  
Distribution Pattern ◽  
Tree Mortality ◽  
Infection Intensity ◽  
Western Hemlock ◽  
Intensity Level ◽  
Dwarf Mistletoe ◽  
Infection Index ◽  
Coastal British Columbia

Surveys of seven western hemlock (Tsugaheterophylla) stands in south coastal British Columbia using fixed-radius plots assessed dwarf mistletoe (Arceuthobiumtsugense) infection intensity level and spatial distribution patterns. Regression analysis indicated a close relationship between the plot infection index (average dwarf mistletoe rating of trees in a plot) and the percentage of infected trees. Plot infection index reached 4.0 when all trees in a plot were infected. Infected trees were either associated with widely spaced infection centers or were more or less evenly distributed throughout the stand. Spatial distribution pattern and spread rate were related to (i) the severity and distribution pattern of the initial inoculum sources, (ii) the manner of stand regeneration and resulting stand structure, and (iii) the presence of barriers to spread such as a high nonhost component and drastic slope increases. Tree mortality from dwarf mistletoe averaged 0.6% (range, 0–1.8%) and was much lower than mortality from other causes. On average, 9.3% of the trees had large dwarf mistletoe caused swellings on the lower third of the bole.

FUNGI FROM DWARF MISTLETOE INFECTIONS IN WESTERN HEMLOCK

1966 ◽  
Vol 44 (5) ◽  
pp. 597-604
Author(s):  
J. A. Baranyay
Keyword(s):  
British Columbia ◽  
Western Hemlock ◽  
Coastal Forest ◽  
Dwarf Mistletoe ◽  
Epicoccum Nigrum ◽  
Fungi Imperfecti

Nine ascomycetes and two fungi imperfecti were found associated with cankers on branch swellings caused by western hemlock dwarf mistletoe, Arceuthobium campylopodum Engelm. forma tsugensis Gill, in an investigation in the coastal forest of British Columbia. One ascomycete is described as Durandiella tsugae sp. nov. The following fungi are discussed: Lachnellula agassizii (Berk, and Curt.) Dennis, Caliciopsis pseudotsugae Fitzp., Capnodium spongiosum Barr, Durandiella tsugae Baranyay sp. nov., Helotium sp., Lophium mytilinum (Pers.) Fries, Mytilidion tortile (Schw.) Ell. & Ev. non Sacc, Retinocyclus abietis (Crouan) Groves & Wells, Biatorella resinae (Fr.) Mudd., Epicoccum nigrum Link, and Truncatella truncata (Lév.) Steyaert.

Potebniamyces gallicola n.sp., from dwarf mistletoe infections in western hemlock

1981 ◽  
Vol 59 (9) ◽  
pp. 1610-1612 ◽  
Author(s):  
A. Funk ◽  
R. B. Smith
Keyword(s):  
British Columbia ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Dwarf Mistletoe

Potebniamyces gallicola n.sp. is described from dwarf mistletoe galls (Arceuthobium tsugense (Rosendahl) G. N. Jones) on western hemlock (Tsuga heterophylla (Raf.) Sarg.), growing in British Columbia, Canada. It has a typical Phacidiopycnis anamorph which is produced both in the host and in culture, as well as hyphal "bud" conidia produced in fresh agar cultures.

TOXICITY OF SMOKE FROM SPOROPHORES OF THE INDIAN PAINT FUNGUS AND WOOD FROM WESTERN HEMLOCK TO YELLOWFEVER MOSQUITOES

1987 ◽  
Vol 119 (12) ◽  
pp. 1109-1115
Author(s):  
W.P.L. Osborn ◽  
J.H. Borden
Keyword(s):  
British Columbia ◽  
Aedes Aegypti ◽  
Combustion Products ◽  
Tsuga Heterophylla ◽  
Water Soluble ◽  
Western Hemlock ◽  
Aqueous Extracts ◽  
Smoke Water

AbstractTo mitigate the effects of mosquitoes, settlers in the Revelstoke area of British Columbia reportedly burned the sporophores of the Indian paint fungus, Echinodontium tinctorium (Ell. & Ev.) Ell. & Ev., a pathogen of western hemlock, Tsuga heterophylla (Raf.) Sarg., and true firs, Abies spp. Larval and adult yellowfever mosquitoes, Aedes aegypti (L.), were exposed to aqueous extracts of smoke (smoke-waters) from E. tinctorium sporophores, and from western hemlock sapwood and heartwood. Smoke-waters were of approximately equal toxicity to larvae. Fungus smoke-water, but not sapwood or heartwood smoke-waters, lost 50% of its potency in 5 months. Vapors from fungus smoke-water were significantly more toxic to adult mosquitoes than those from sapwood or heartwood. Thus smoke from E. tinctorium sporophores and T. heterophylla wood apparently contain different water-soluble combustion products toxic to A. aegypti.

STUDIES IN FOREST PATHOLOGY: VII. DECAY IN WESTERN HEMLOCK AND FIR IN THE FRANKLIN RIVER AREA, BRITISH COLUMBIA

1949 ◽  
Vol 27c (6) ◽  
pp. 312-331 ◽  
Author(s):  
D. C. Buckland ◽  
R. E. Foster ◽  
V. J. Nordin
Keyword(s):  
British Columbia ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Forest Pathology ◽  
Abies Amabilis ◽  
Armillaria Mellea ◽  
Forest Region ◽  
Volume Increment ◽  
Juan De Fuca

An investigation of decay in western hemlock (Tsuga heterophylla (Raf.) Sarg.) and fir (mainly Abies amabilis (Loud.) Forb.) in the Juan de Fuca forest region of British Columbia has shown that the major organisms causing root and butt rots are the same in both species. These are Poria subacida (Peck) Sacc., Fomes annosus (Fr.) Cke., Armillaria mellea Vahl ex Fr., Polyporus sulphureus Bull. ex Fr., and P. circinatus Fr. Those organisms causing trunk rots of western hemlock, in decreasing order of importance, are Fomes pinicola (Sw.) Cke., F. Pini (Thore) Lloyd, Stereum abietinum Pers., Fomes Hartigii (Allesch.) Sacc. and Trav., and Hydnum sp. (H. abietis). These same organisms causing trunk rots of fir, in decreasing order of importance, are Fomes pinicola, Stereum abietinum, Hydnum sp. (H. abietis), Fomes Pini, and Fomes Hartigii. The logs of 963 western hemlock were analyzed in detail. Maximum periodic volume increment was reached between 225 and 275 years of age. Maximum periodic volume increment was reached between 275 and 325 years of age in the 719 fir that were analyzed. Scars were the most frequent avenue of entrance for infection. In 59% of the cases of infection studied the fungus had entered through wounds.

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