Hygrophorus vernalis is a rare “snowbank” fungus forming ectomycorrhiza with conifers in high elevation forests in the Olympic, Cascade and Rocky Mountains in western North America. It produce fruitbodies in the spring and summer on the edges of melting snowbanks. Climate change is causing warmer and drier winters with elevated and lessened average snowfall which is causing a gradual, continued loss and deterioration of appropriate habitat for this species. A population decline of over 30% can be inferred over the next several decades. The species is assessed as Vulnerable.

Described by Smith (1941) from a collection made at Dear Lake, in Olympic National Park, Washington, USA.

Hygrophorus vernalis is a rare snowbank fungus, ectomycorrhizal with conifers in areas with deep winter snowpack in the Pacific Northwest mountains.

Currently known from seven locations, and experiencing decline in suitable habitat.

Confined to Western North America and known from Washington and Idaho in USA and from British Columbia, Canada. Several observations from Mount Shasta in northern California have been reported.

This snowpack fungus was described from the Olympic Peninsula in Washington. It is considered rare as it is currently known from nine sites in total: 3 from the Washington Cascade Range, one in eastern Washington, one in Idaho, one in British Columbia, Canada plus three observations from Mount Shasta in northern California (MyCoPortal 2024).  It is confined to old growth high elevation conifer forests. While it is certainly over-looked within its habitat restricted geographic distribution, the total number of locations is conservatively estimated to be less than 500 corresponding to fewer than 15000 mature individuals.

Its habitat is being drastically affected by changing climate; with warmer and drier winters that have elevated and lessened the average snowfall. Stoelinga et al. (2010) state that Cascade Range spring snowpack declined 23% during 1930-2007 while Fyfe et al 2017 cite a 21.8% loss between 1982-1993 and 2000-2010 and models suggest that the rate of snowpack decline will increase substantially by the end of the century (Mote et al 2005, 2018, Rhoades et al. 2018).  As this species is restricted to snowbanks, a population decline of over 30% can be inferred over the next several decades. 

 

Hygrophorus vernalis is an ectomycorrhizal fungus occurring in high elevation forest with Pinaceae, maybe also associating with hemlock. Fruiting in late spring or early summer, when winter snowpacks melt.  The fruitbodies occur scattered on melting snowbanks; often growing up through the snow, or on the immediate edge of banks. Ectomycorrhizal fungal mycelia is perennial and may live for several decades and potentially much more longer with a continuous presence of living trees in appropriate habitats.

Hygrophorus vernalis is a rare mycorrhizal snowbank fungus dependent on thick winter snowpacks to fruit. Snowbank fungi, unique to the western North American mountains, occur in areas with ample snowpack. They fruit in the spring and summer, as the snow melts and recedes. As the climate changes, warmer and drier winters have elevated and lessened the average snowfall.  Climate change, continued loss of habitat, decline in area of old growth forests, and hotter, stand replacing fires are detrimental to this species. 

Snowpack decline in the western North American mountains has been well documented (Mote et al. 2005, Mote et al 2018, Zeng et al. 2018, Stoelinga et al. 2010). Stoelinga et al. (2010) state that Cascade Range spring snowpack declined 23% during 1930-2007, and models suggest that the rate of snowpack decline with increase substantially by the end of the century (Rhoades et al. 2018).

Protect known populations from logging and development.

Attempts should be made to identify the ectomycorrhizal associate/s of this species. Identify habitat this species occurs in, and survey for additional populations.

None known.

Castellano, M., Smith, J.E., O’Dell, T., Cázares, E. and Nugent, S. 1999. Handbook to Strategy 1 Fungal Species in the Northwest Forest Plan. General Technical Report PNW-GTR-476. United States Department of Agriculture.

Cooke, W.B. 1955. Subalpine fungi and snowbanks. Ecology 36: 124–130.

Fyfe, J. C. et al. 2017. Large near-term projected snowpack loss over the western United States. Nat. Commun. 8, 14996 doi: 10.1038/ncomms14996.

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

Mote, P.W., Hamlet, A.F., Clark, M.P. and Lettenmaier, D.P. 2005: Declining mountain snowpack in western North America. Bulletin of the American Meteorological Society 86, 39–49.

Mote, P.W., Li, S., Lettenmaier, D.P. et al. 2018. Dramatic declines in snowpack in the western US. npj climate and atmospheric science 1, 2 (2018). https://doi.org/10.1038/s41612-018-0012-1

Rhoades, A.M., Jones, A.D. and Ullrich, P.A. 2018. The Changing Character of the California Sierra Nevada as a Natural Reservoir. Geophysical Research Letters. DOI: 10.1029/2018GL080308

Siegel, N. 2017. United States Forest Service R5 rare species assessment. Draft internal document. 

Smith, A.H. 1941. Studies of North American agarics -I. Contributions from the University of Michigan Herbarium. 5: 1–73.

Stoelinga, M.T., Albright, M.D. and Mass, C.F. 2010. A new look at snowpack trends in the Cascade Mountains. Journal of Climate 23: 10. 2473–2491. https://doi.org/10.1175/2009JCLI2911.1