Management Recommendations•Group 11

Uncommon Gilled Mushrooms: Hygrophorus caeruleus Miller and Hygrophorus vernalis A. H. Smith

TABLE OF CONTENTS

EXECUTIVE SUMMARY

Taxa: Hygrophorus caeruleus Miller and Hygrophorus vernalis A. H. Smith

Taxonomic Group: Fungi

ROD Component(s): 1 & 3

Other Management Status: Both taxa are listed as sensitive species in a preliminary report on endangered, threatened and sensitive macrofungi of Washington State by Ammirati (1994).

Range: Hygrophorus caeruleus is endemic to western North America. It is rare within the range of the northern spotted owl where it is known from the Cascade Mountains in Oregon and Washington. Hygrophorus vernalis is endemic to a portion of the range of the northern spotted owl. It is known from the Cascade Mountains in Washington and California.

Specific Habitat: Both taxa are ectomycorrhizal associates of Pinaceae, H. caeruleus may be restricted to Abies. They typically fruit in mid-elevation to montane conifer forests in spring near melting snowbanks.

Threats: Logging of is the most serious threat to both taxa. Since most populations are in protected areas of Federal ownership with high recreational use, road, trail, and campground construction could potentially impact these taxa.

Management Recommendations: Maintain habitat for both Hygrophorus caeruleus H. vernalis at known sites by retaining old growth forest structure and soil conditions. Avoid disturbance at known sites, including modification of canopy until additional data is collected on species viability.

Information Needs: Revisit known sites of both taxa and collect ecological data to more completely characterize habitat. Conduct inventories, particularly in late-successional reserves, Research Natural Areas and when appropriate where management treatments or projects are scheduled or proposed.

I. NATURAL HISTORY

A. Taxonomic/Nomenclatural History

Hygrophorus caeruleus was originally described from Bear Basin, Idaho by Miller (1984). There are no known synonyms. It is a gilled mushroom in the family Hygrophoraceae in the order Agaricales.

Hygrophorus vernalis was originally described from Deer Lake, Olympic National Park by Smith (1941). There are no known synonyms. It is a gilled mushroom in the family Hygrophoraceae in the order Agaricales.

B. Species Description

These fungal taxa are grouped together because they both belong to the family Hygrophoraceae and form similarly structured epigeous sporocarps.

1. Morphology

Hygrophorus caeruleus is a robust, blue-tinged, gilled mushroom with blue-green waxy gills, aconspicuous basal rhizomorph and a distinctly farinaceous odor. It fruits near melting snowbanks with Pinaceae. Hygrophorus canescens and H. pallidus have similar stature and coloration, but have no odor, interwoven gill trama, smaller spores, different cuticular morphologies, and different plant associates. Hygrophorus subviolaceus is similarly colored but has interwoven lamellar trama, a pileus cuticle with narrower (2-3 µm diam) hyphae, and a more fragile, slender stature.

Basidiospores (6.5-) 7-9 x 4-5 µm, elliptical, thin-walled, inamyloid; pileipellis an ixocutis of 2.5-5 µm diam thin-walled, hyaline hyphae; lamellar trama parallel; clamp connections numerous.

Hygrophorus vernalis is a white to yellow-brown gilled mushroom with a viscid pileus, sordid white gills and stipe with a thin glutinous layer on the base. It also fruits near melting snowbanks with Pinaceae. Hygrophorus variicolor has a darker pileus lacking vinaceous tones and much smaller spores (7-9 x 4.5-5.5 µm).

Pileus 30-50 mm broad, obtusely umbonate with incurved margin, viscid, moderate yellowish brown when young, becoming tinged with brighter pale vinaceous colors in age. Context thick, concolorous with cuticle or whitish vinaceous. Odor and Taste not distinctive. Lamellae arcuate, becoming long decurrent, whitish or paler than pileus margin. Stipe 40-60 x 7-9 mm, equal to slightly bulbous, whitish, with the thin layer of gluten on the lower portion forming shiny dingy yellowish patches. Basidiospores 11-15.5 x 5.5-7 µm, oblong ellipsoid, smooth, inamyloid. Basidia 50-70 x 7-11 µm, 2- & 4-spored. Gill trama divergent. Pleurocystidia and cheilocystidia absent. clamp connections rare (cuticular hyphae) to relatively common (gill trama).

2. Reproductive Biology

Both taxa are mushrooms and thus are presumed to be dependent on wind for dispersal of spores. No specific information on reproductive biology is available for any of these taxa at this time.

3. Ecology

Both taxa are presumed ectomycorrhiza formers. Mycorrhiza is the symbiotic, mutually beneficial association between a fungus and plant root. This highly interdependent relationship is based on the translocation of mineral nutrients and water by the fungus to the host plant while the fungus obtains photosynthetic carbon from the host plant. Some mycorrhizal associations are highly specific. Many plants depend upon mycorrhizal fungi for adequate uptake of nutrients and survival in nature. Likewise mycorrhizal fungi depend upon their host plant for carbohydrate. No specific ecological information is available for either taxa at this time except that both taxa form ectomycorrhiza with Pinaceae.

C. Range, Known Sites

Hygrophorus caeruleus is endemic the range of the northern spotted owl and is known from 2 sites: Washington, Kittitas Co., Twenty-nine Pines and Oregon, Jefferson Co., Deschutes National Forest, Jack Creek.

Hygrophorus vernalis is endemic to the range of the northern spotted owl and is known from 3 sites in Washington: , Clallam Co., Olympic National Park, near Deer Lake; Clallam Co., Olympic National Park, Hell Creek; Clallam Co., Olympic National Park, near Elwha campground.

D. Habitat Characteristics and Species Abundance

Both taxa occur in soil in association with roots of Pinaceae spp. near melting snowbanks in spring.

II. CURRENT SPECIES SITUATION

A. Why Species is Listed under Survey and Manage Standards and Guidelines

Both taxa are rare in California, Oregon, and Washington. Under option 9, these taxa were considered to have a 5 percent likelihood of being well distributed throughout their range, 50 percent likelihood of being locally restricted, 28 percent likelihood of restriction to refugia, and 18 percent likelihood of extirpation on Federal lands.

B. Major Habitat and Viability Considerations

The major viability considerations for Hygrophorus caeruleus and H. vernalis are loss of the known populations within the range of the northern spotted owl. Considerations include all management or recreational activities that remove host trees or disturb the soil and duff. The presence of extant populations in high recreational use areas exposes it to adverse impact due to management or recreational activities, particularly those that disturb the soil or damage host trees.

The autecology of these taxa is not well known. They are presumed ectomycorrhiza formers associated with Pinaceae. Therefore disturbance that affects the host will potentially strongly affect these taxa.

Climate change may result in decline in vigor of these taxa and may result in the extirpation of these taxa from the range of the northern spotted owl. Climate change could potentially impact all populations of both taxa. An increase in temperature or a decrease in precipitation could affect all populations.

C. Threats to the Taxa

Threats to Hygrophorus caeruleus and H. vernalis are those actions that disrupt stand conditions necessary for their survival particularly removal of Pinaceae, and associated litter, humus and soil. These include logging, road, trail, and campground construction that remove its litter, duff or potential mycorrhizal hosts, or otherwise modify microclimate.

These taxa are not routinely harvested for use as food.

D. Distribution Relative to Land Allocations

Of the two known sites for Hygrophorus caeruleus , one is in matrix land on the Deschutes National Forest and the other site is on non-Federal land in Kittitas Co., Washington. All 3 sites for H. vernalis are on congressionally withdrawn land in Olympic National Park.

III. MANAGEMENT GOALS AND OBJECTIVES

A. Management Goals for Taxon

The goal for the management of these taxa is to assist in maintaining extant populations within the assessment area. Known sites on Federal land of these rare taxa should be protected until sufficient information is generated to suggest management can sustain taxon viability, particularly on Federal land.

B. Specific Objectives

Maintain habitat conditions at all known sites on Federal land for both taxa.

The seemingly preferred habitat of the above two taxa is also somewhat under-collected by mycologists and in critical need of survey. New populations may be found with additional surveys.

IV. HABITAT MANAGEMENT

A. Lessons from History

There has not been any specific management of sites for Hygrophorus caeruleus or H. vernalis. Since both taxa are presumptive mycorrhiza formers and fruit in humus, the host and its litter and humus should be protected where populations exist. When mycorrhiza host trees are damaged or removed a negative impact is usually reflected in the population of the fungal partner. Although not documented for these taxa, many fungi are harmed by air pollution, acid deposition, N deposition, and SOx (Gulden et al., 1992).

B. Identification of Habitat Areas for Management

One reported site of Hygrophorus caeruleus within the range of the northern spotted owl is matrix land on Deschutes National Forest. This area should be managed to maintain the viability of this population. The other known population is on non-Federal land.

The reported sites of Hygrophorus vernalis within the range of the northern spotted owl are in Olympic National Park.

C. Management Within Habitat Areas

Status of specific management activities is unknown for extant sites. However, at and around known sites, it is recommended that current habitat conditions and micro-climatic conditions be maintained, impacts from soil disturbing activities minimized, and damage or removal of host trees be prevented.

The only known location on Federal land of Hygrophorus caeruleus should be managed to include an area that is large enough to maintain the habitat and associated micro-climate of the population. The Regional mycologist is available to consult with field staff and managers on the size of the appropriate area for management.

• Maintain dominance of specific host tree associates as outlined in section 1D, which are necessary for mycorrhizal association.
• Minimize loss, disruption or compaction of soil particularly from management, road, trail and campground construction or recreational activities.
• Manage tree diseases in the area to minimize loss of host trees.

D. Other Management Issues and Considerations

No additional management issues or considerations are identified at this time.

V. RESEARCH, INVENTORY, AND MONITORING NEEDS

A. Data Gaps and Information Needs

Revisit known sites of both taxa to collect ecological data to more completely characterize habitat. Conduct surveys to locate additional populations of both taxa particularly in late-successionalreserves, Research Natural Areas, and when appropriate where management treatments or projects are scheduled or proposed.

Data are lacking regarding the specific response of these taxa to management practices such as logging, road, trail, and campground construction, prescribed fire and collection of secondary forest products. Also needed are information on each fungus species concerning the area required to support viable populations, population age structure, dispersal requirements and maximum distance over which populations can interact. Exact host tree associations for each fungus species need documentation.

B. Research Questions

• What are the respective the ecological amplitudes of Hygrophorus caeruleus and Hygrophorus vernalis, particularly are they restricted to fruiting in associating with Pinaceae near melting snow?
• How do both taxa respond to manipulation or modification of the micro-climate?
• What is the range of suitable microclimate conditions, particularly humidity, soil moisture, and soil temperature?
• What is the relationship of stand age to population viability for both taxa?
• What is the density of tree hosts needed to sustain viability of the population?

C. Monitoring Needs and Recommendations

Known sites of both taxa should be revisited periodically to assess compliance with management guidelines and evaluate impacts.

VI. REFERENCES

Ammirati, J. 1994. Endangered, threatened and sensitive macrofungi of Washington State. Official Letter to C. Turley, Science team leader, Washington State Dept. of Natural resources. Dated March 26, 1994.

Gulden, G., K. Hoiland, K. Bendiksen, T.E. Brandrud, B.S. Foss, H.B. Jenssen, and D. Laber. 1992. Macromycetes and Air Pollution: Mycocoenological studies in three oligotrophic spruce forests in Europe. Bibliotheca Mycologica 144: 1-81.

Hesler, L. R., and A. H. Smith. 1963. North American Taxa of Hygrophorus. Knoxville: The University of Tennessee Press.

Largent , D. L. 1985. The Agaricales of California. 5. Hygrophoraceae. Eureka: Mad River Press, Inc. 208 pp.

Miller, O. K. Jr. 1984. A new taxa of Hygrophorus from North America. Mycologia 76(4): 816-820.

Norvell, L.L. 1996. unpublished report on file, Forestry Sciences Lab. Corvallis, Oregon.