Many higher plants have mycorrhizae associated with their roots. These structures are often essential for survival and growth (Harley & Smith 1983). Mycorrhizae are known for the abilities to enhance nutrient absorption. While nitrogen-fixing organisms are found as components of the mycorrhizosphere, mycorrhizal fungi are not presently known to fix...
Seedlings of Gaultheria shallon, Pseudotsuga menziesii, Rhododendron macrophyllum and Tsuga heterophylla were grown together in the greenhouse in soils from three young managed Douglas-fir forests in the Oregon Coast Range. The main objectives were 1 )to evaluate the ability of ericaceous plants and overstory conifers to share compatible mycorrhizal fungi...
Fusarium spp. frequent conifer nursery soils yet are rarely recovered from coniferous forest soils. Experiments were performed to determine what influence humic-rich organic amendments and volatiles from soil, ectomycorrhizal fungi and ectomycorrhizae have on the populations of several physiologic and taxonomic microbial groups potentially related to this phenomenon. A comparative...
Seedlings of Pseudotsuga menziesii (Mirb.) Franco and Betula papyrifera Marsh. were grown in the greenhouse in monoculture and dual culture in soils collected from a young mixed species plantation in the southern interior of British Columbia. The objectives of the study were (i) to evaluate the ability of P. menziesii...
Basidiospores of Rhizopogon viriicolor Smith and R. colossus
Smith were inoculated onto container-grown Douglas-fir (Pseudotsuga
menziesii (Mirb.) Franco) seedlings and grown under two levels of
soluble fertilizer and one level of slow-release fertilizer. Both
fungi formed abundant (54%) ectomycorrhizae under the soluble
fertilizer regimes. Slow-release fertilizer greatly reduced percent
ectomycorrhizae...
Beginning in the 1980s, large-scale commercial harvest of Tricholoma magnivelare created a need for management of forests to ensure sustainability, but little was known of the biology or ecology of this species to guide management decisions. Four of the five studies presented here explore the basic synecology of T. magnivelare...
Douglas-fir seedlings were inoculated with different species of
ectomycorrhizae-forming fungi in order to test the concept that
ectomycorrhizae enhance the drought tolerance of seedlings and to
investigate the mechanisms responsible for this effect.
Seedlings were transplanted at age 6 to 8 weeks into pots
containing pasteurized loam soil and inoculated...
Results from approximately 400 fungus-host pure culture
inoculations indicate that specificity of ectomycorrhizal associations
is a complex phenomenon and cannot be based solely on field observations
of sporocarp-host associations. Of the numerous sporocarp-host
specific fungi tested, most formed ectomycorrhizae with one or more
unexpected, non-associated hosts. These results conclusively demonstrate...
Recent surveys of belowground fungal biodiversity in Mexico and USA have revealed many undescribed truffle species, including many in the genus Tuber. Here we describe seven new species: Tuber beyerlei, T. castilloi, T. guevarai, T. lauryi, T. mexiusanum, T. miquihuanense and T. walkeri. Phylogenetic analyses place these species within the...
Solioccasus polychromus gen. & sp. nov., the most brightly colored hypogeous fungus known, is described from Papua New Guinea and tropical northern Australia south into subtropical forests along the Queensland coast and coastal mountains to near Brisbane. Phylogenetic analysis of molecular data places it as a sister genus to Bothia...
Most higher plants have evolved with an obligatory symbiotic relationship with my corrhizal fungi. Epigeous mycorrhiza formers have their spores dispersed by air currents, but hypogeous mycorrhizal fungi are dependent upon small mammals as primary vectors of spore dissemination. Mammalian mycophagists defecate within the coniferous forest ecosystem, spreading the viable...
Cenococcum is a genus of ectomycorrhizal Ascomycota that has a broad host range and geographic distribution. It is not known to produce either meiotic or mitotic spores and is known to exist only in the form of hyphae, sclerotia and host-colonized ectomycorrhizal root tips. Due to its lack of sexual...
Giant chinquapin (Chrysolepis chrysophylla) is an evergreen hardwood often found as a shrubby understory component of coniferous forests in the Pacific Northwest United States. Due to its ability to sprout quickly after disturbances such as fire and logging it is often viewed as a pest by forest managers. Like its...
Rhizopogon subgenus Villosuli are the only
members of the genus known to form an ectomycorrhizal
relationship exclusively with Pseudotsuga. The
specificity of this host relationship is unusual in that
Rhizopogon is broadly associated with several tree
genera within the Pinaceae and relationships with a
host genus are typically distributed across...
Detailed analysis of mixed-conifer and red fir forests were made from extensive, large vegetation sampling, systematically conducted throughout the Teakettle Experimental Forest. Mixed conifer is characterized by distinct patch conditions of closed-canopy tree clusters, persistent gaps and shrub thickets. This heterogeneous spatial structure provides contrasting microclimate, habitat and resource conditions...
Post-fire Pezizales often fruit seasonally approximately six weeks after a fire in successional groups over the course of two years. Two methods, pure culture synthesis and PCR-based identification, were used to determine if some of these species were mycorrhizal. Eleven fungal isolates, Anthracobia melaloma, Gyromitra infula, Helvella compressa, Morchella sp.,...
Rhizopogon is a hypogeous fungal genus that forms ectomycorrhizae
with genera of the Pinaceae. The greatest number and species of
Rhizopogon are found in coniferous forests of the Pacific Northwestern
United States, where members of the Pinaceae are also concentrated.
Rhizopogon spp. are host-specific primarily with Pinus spp. and
Pseudotsuga...
We investigated the root endophytic fungi of lupine using
four approaches: (1) occurrence of fungal colonization in field-collected
roots; (2) growth response of L. latifolius to inoculation
with two types of fungi; (3) structure of root colonizations of
Pinus and Lupinus by Phialocephala fortinii, a septate endophytic
fungus of lupine;...
The overall goal of this study was to investigate influences of ectomycorrhizae (EM) and
interspecific carbon transfer on seedling performance in species mixtures. The objectives were to:
(I) determine the potential for EM to link paper birch and Douglas-fir, (ii) quantify gross and net
interspecific carbon transfer, and (iii) evaluate...
These studies are part of the Demonstration of Ecosystem Management Options (DEMO) study, a program researching the effects of different levels and patterns of green-tree retention on ecological, economic, and social phenomena. We restricted our studies to the 15% basal area, evenly dispersed retention treatment. Our objectives were, first, to...
