Ectomycorrhizal community structure across forest openings on naturally regenerated western hemlock seedlings

1998 ◽  
Vol 76 (2) ◽  
pp. 189-196 ◽  
Author(s):  
J M Kranabetter ◽  
T Wylie
Keyword(s):  
Forest Canopy ◽  
Forest Edge ◽  
Soil Disturbance ◽  
Tsuga Heterophylla ◽  
Community Diversity ◽  
Western Hemlock ◽  
Competitive Balance ◽  
Cenococcum Geophilum ◽  
Ectomycorrhizal Community ◽  
Forest Openings

We examined the diversity and distribution of ectomycorrhizal morphotypes on naturally regenerated western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings across small forest openings (50-75 m in diameter) in northwest British Columbia. The total and average morphotype richness decreased across the 4-year-old forest openings despite the rapid establishment of western hemlock and lack of soil disturbance. Average fungal richness decreased from 13.1 morphotypes under the forest canopy to 9.6 at the forest edge (27% reduction) and to 7.8 in the forest opening (40% reduction). Cenococcum geophilum, Mycelium radicis atrovirens, and Lactarius I were the most abundant ectomycorrhizae at each gap position, and none of the ectomycorrhizal fungi found in openings were eliminated by "late-stage" fungi in mature stands. This fungal distribution supports the "multistage" concept of ectomycorrhizal succession. Seedlings under the forest canopy had a total of 38 fungal morphotypes in a relatively even distribution pattern that corresponded well to the "random niche boundary" hypothesis. Fungal distributions were progressively less even for seedlings at the forest edge and opening than for seedlings beneath the canopy, perhaps because reduced fungal diversity and hyphal inoculum had affected the competitive balance of the ectomycorrhizal community.Key words: ectomycorrhizal community, diversity, succession, forest gaps.

First-year survival of Tsuga heterophylla without mycorrhizae and subsequent ectomycorrhizal development on decaying logs and mineral soil

1982 ◽  
Vol 60 (9) ◽  
pp. 1601-1605 ◽  
Author(s):  
E. Jennifer Christy ◽  
Phillip Sollins ◽  
James M. Trappe
Keyword(s):  
Mineral Soil ◽  
Root Systems ◽  
Growing Season ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
First Year ◽  
Cenococcum Geophilum ◽  
Piloderma Croceum

Roots of western hemlock (Tsuga heterophylla) seedlings 1–5+ years old that had established naturally on logs in three states of decay or on mineral soil were compared for numbers and kinds of ectomycorrhizae. Mycobionts colonizing root systems included Cenococcum geophilum Fr., Piloderma croceum (Bres.) Erikss. & Hjorts., and four unidentified fungi distinguished by color and morphology. About half the seedlings surviving the first growing season (2–7 months) were nonmycorrhizal. Nonmycorrhizal seedlings were most frequent on the least decayed logs. However, mycotrophy appeared to be advantageous to hemlock; 1st-year mycorrhizal seedlings had shoots 60% longer and roots 47% longer than 1st-year nonmycorrhizal seedlings. All 2nd-year and older seedlings were mycorrhizal. The ability of western hemlock to survive the first growing season without mycorrhizae may contribute to its success in colonizing decaying logs, which may contain microsites devoid of effective ectomycorrhizal inocula.

Ectomycorrhizal community structure on western hemlock (Tsuga heterophylla) seedlings transplanted from forests into openings

2002 ◽  
Vol 80 (8) ◽  
pp. 861-868 ◽  
Author(s):  
J M Kranabetter ◽  
J Friesen
Keyword(s):  
Fungal Community ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Stand Development ◽  
Mature Forest ◽  
Rooting Density ◽  
Ecm Fungi ◽  
Forest Openings ◽  
Hyphal Contact ◽  
Species Importance

This study tested whether mature-forest ectomycorrhizal (ECM) communities could be maintained in forest openings on seedlings. Naturally regenerated western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings were transplanted from mature forests into openings and the ECM fungal community was compared after 2 years with similar seedlings planted back into the forests or seedlings from openings planted back into openings. Fewer ECM morphotypes, lower average richness per seedling, and a steeper, less even species distribution curve were found, all of which suggest that the mature-forest ECM fungal community changed after transplanting forest seedlings into the openings. The increased abundance of pioneer fungi such as Thelephora terresteris suggested that many of the mature-forest ECM fungi were unable to maintain or continue root colonization in openings. Results suggest that many mature-forest ECM fungi require further stand development to maintain enough rooting density and hyphal contact to persist.Key words: ectomycorrhizal succession, disturbance, species-importance curves, multistage and late-stage fungi.

Spatial distribution and succession of epiphytes on Tsuga heterophylla (western hemlock) in an old-growth Douglas-fir forest

2000 ◽  
Vol 78 (7) ◽  
pp. 957-968 ◽  
Author(s):  
Betsy Lyons ◽  
Nalini M Nadkarni ◽  
Malcolm P North
Keyword(s):  
Forest Canopy ◽  
Spatial Scales ◽  
Coniferous Forest ◽  
Tsuga Heterophylla ◽  
Forest Understory ◽  
Western Hemlock ◽  
Old Growth ◽  
Old Growth Forest ◽  
Crown Structure ◽  
Large Trees

We examined the distribution and abundance of nonvascular epiphytes on western hemlock trees in an old-growth coniferous forest focusing on patterns of epiphyte distribution at different spatial scales, epiphyte abundance amongst trees differing in size, and crown structures associated with epiphyte abundance. Total epiphyte cover was greatest in four canopy microhabitats: the upper canopy strata, crowns of large trees, lower crown branches, and inner branch plots. Epiphyte functional groups were stratified vertically within the stand and horizontally within branches. Alectorioid and "other" lichens were most abundant in the upper canopy and outer branch plots. Cyanolichens and Sphaerophorus globosus (Huds.) Vain. were most abundant in the lower to mid canopy. Although cyanolichens were most abundant in middle branch plots, Sphaerophorus was most abundant in inner branch plots. Bryophytes were most abundant in the lower canopy and inner branch plots. At the stand level, canopy height and tree size were the main influences on epiphytes. Within trees, plots closer to the tree trunk and lower in the crown had the greatest abundance of epiphytes. In this forest, understory trees were colonized first by bryophytes, not by alectorioid and "other" lichens as is common for small trees in young stands.Key words: epiphyte succession, lichens, western hemlock, old growth, forest canopy, crown structure.

Growth ofPseudotsuga menziesiiandTsuga heterophyllaseedlings along a light gradient: resource allocation and morphological acclimation

1997 ◽  
Vol 75 (9) ◽  
pp. 1424-1435 ◽  
Author(s):  
D. Mailly ◽  
J. P. Kimmins
Keyword(s):  
Leaf Morphology ◽  
Biomass Accumulation ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Low Light ◽  
Growing Seasons ◽  
Light Levels ◽  
Light Gradient ◽  
Relative Light Intensity

Silvicultural alternatives that differ in the degree of overstory removal may create shady environments that will be problematic for the regeneration of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Gradients of light in the field were used to compare mortality, growth, and leaf morphological acclimation of two conifer species of contrasting shade tolerances: Douglas-fir and western hemlock (Tsuga heterophylla (Raf.) Sarg.). Results after two growing seasons indicated that Douglas-fir mortality occurred mainly at relative light intensity (RLI) below 20%, while western hemlock mortality was evenly distributed along the light gradient. Height, diameter, and biomass of the planted seedlings increased with increasing light for both species but at different rates, and maximum biomass accumulation always occurred in the open. Douglas-fir allocated more resources to stem biomass than western hemlock, which accumulated more foliage biomass. Increases in specific leaf area for Douglas-fir seedlings occurred at RLI ≤ 0.4 and red/far red (R/FR) ratio ≤ 0.6, which appear to be the minimal optimum light levels for growth. Conversely, western hemlock seedlings adjusted their leaf morphology in a more regular pattern, and changes were less pronounced at low light levels. These results, along with early mortality results for Douglas-fir, suggest that the most successful way to artificially regenerate this species may be by allowing at least 20% of RLI for ensuring survival and at least 40% RLI for optimum growth. Key words: light, light quality, leaf morphology, acclimation.

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.

Genotype × shade effects for western hemlock

2005 ◽  
Vol 35 (6) ◽  
pp. 1496-1501
Author(s):  
G R Johnson ◽  
C Cartwright
Keyword(s):  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Different Levels

Western hemlock (Tsuga heterophylla (Raf.) Sarg.) families were grown under different levels of shade for 2 or 3 years at two nursery sites to determine whether families performed differently relative to one another in the different shade environments. Differences were found both for levels of shade and families, but no family × shade interaction was found. Results suggest that families selected in full-sun environments (clearcuts or farm fields) may be well suited for use in silvicultural systems where seedlings are planted in understory conditions.

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

A SAMPLING SYSTEM FOR EGGS OF WESTERN BLACKHEADED BUDWORM, ACLERIS GLOVERANA (WALSINGHAM) (LEPIDOPTERA: TORTRICIDAE), ON WESTERN HEMLOCK, TSUGA HETEROPHYLLA (RAF.) SARG.

1990 ◽  
Vol 122 (3) ◽  
pp. 555-562 ◽  
Author(s):  
R.F. Shepherd ◽  
T.G. Gray
Keyword(s):  
Sequential Sampling ◽  
Lower Surface ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Sampling System ◽  
Relative Contribution ◽  
Egg Density ◽  
Branch Weight ◽  
Branch Size ◽  
Criteria For Selection

AbstractEggs of western blackheaded budworm, Acleris gloverana (Walsingham), are laid on the lower surface of western hemlock, Tsuga heterophylla (Raf.) Sarg., needles. A comparison was made of the following measures of sample branch size as a basis for expressing egg density: fresh branch weight, branch area, total twig length, branch volume, and number of buds. The criteria for selection of these measures were as follows: correlations of branch size with dry needle weight, variances of egg density and their relative contribution to sample size, and ease of measurement. Fresh branch weight was the best choice. A sequential sampling system was developed on this basis and was related to a scale of predicted defoliation. In addition, a transformation was provided for use in data analysis.

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