Revised OR COULD IT QUALIFY FOR DECLINE AND HENCE COMPLY with NT or VU? -
LC suggested - However, in British Columbia, Canada, Arbutus distribution is at its northernmost range, and T. punicea sites are limited to southern Vancouver Island coastal areas where large mature trees are at risk due to declining populations, likely resulting in a NT listing specifically for the Canadian population. The habitat for the fungus, in this northern range of its tree host, is under threat from urban encroachment, forest fire suppression and disease, all of which have contributed to a well-documented decline of Arbutus in the scientific literature (although publications to date do not estimate the rate of decline). The much larger Arbutus population size observed in California supports estimated numbers of mature individuals at levels of least concern within the next 100 years, even if in this time frame there was a proven significant reduction (>30%) of Arbutus due to decline.
Basionym: Pholiota punicea A.H. Sm. & Hesler, North
Am. Species of Pholiota: 40. 1968
This mushroom has a dark-red to reddish-purple cap, vinaceous gills that at maturity become ochre-brown to cinnamon-brown from the spores, and a vinaceous stipe. Its fruits on rotting madrone and this substrate helps distinguish it from a very closely related species, Tubaria vinicolor which occurs on woody debris in disturbed habitats
This species has a very restricted habitat (hollowed bases of big Arbutus menziesii Pursh. trees). Its habitat in the northern range of its tree host is under threat from urban encroachment, forest fire suppression and disease (Arbutus decline), which have all contributed to a well-documented decline of Arbutus in this area However the larger, more robust Arbutus populations observed in California are likely to maintain the number of mature individuals at levels of least concern.
QUESTION - NO DECLINE IN POTENTIAL HABITAT DURING THE LAST 20 OR 20 YRS TO COME? THE TEXT APPEARS A LITTLE BIT CONTRADICTORY.
Known distribution based on herbarium collections is from south coastal Vancouver Island, British Columbia which is close to the northernmost extent of the range of Arbutus menziesii, south to coastal Marin County, California, with further observations to Monterey County in California (Mushroom Observer). Potential distribution is from south coastal BC to Southern California following the distribution range of the host tree, Arbutus menziesii.
Known from only 8 locations on southern Vancouver Land in British Columbia, Canada, 8 locations in northwest coastal California, USA (from herbarium specimens), and one collection (the type) from the Oregon-California border. Multiple (over 50) sitings reported on Mushroom Observer have been verified as occurring on Arbutus (Pers. comm Else Vellinge), the vast majority coastal. It might appear that the citation of 12 collections from British Columbia would indicate T. punicea is common in this province, but this is not the case. For example, at one Cobble Hill, Vancouver Island site, more than 100 mature trees were examined before two trees were found with the fungus. Other Vancouver Island localities were comparable to Cobble Hill, in number of trees surveyed before the fungus was found. No materials of T. punicea had been deposited at WTU before this study, which further supports its rare status in British Columbia where the habitat is far more limited than further south (Matheny et al. 2007). Collections of T. punicea have been made in 1937 (the type) and then not again until 2005, 2006, 2011-2016. It is considered to be exclusive to Arbutus, which limits the distribution to areas where large trees of this species occur in southwestern British Columbia, where it is restricted to water-shedding sites on southeastern Vancouver Island, the Gulf Islands, and adjacent coastal mainland, southward through Washington, Oregon, and California in the coastal mountains and west slopes of the Sierra Nevada.
Declines in Arbutus trees across their native range have been well documented due to diseases and urbanization. (Elliott, 1995; 2002).
Many Pacific madrones were sampled around the Seattle/Puget Sound area to gauge the effect of urban development and disturbance and whether they facilitated disease transmission and tree mortality. Thinning stands, soil loss and compaction, and a host of urban impacts increased susceptibility to disease. Dense stands of Pacific madrone are less affected by pathogens such as Neofusicoccum arbuti, and it was predicted that an increase in the proportion of seriously diseased trees would occur if forest stands were broken up (Adams et al. 1999). Based on fire suppression and Arbutus decline research and observations, T. punicea populations in Southern BC and Washington may be likewise affected due to habitat loss (fewer remaining large diameter trees with hollow bases). Populations are likely to remain at levels of least concern further south in California where the host tree occurs in dense large stands.
Population Trend: Uncertain
Tubaria punica is a saprotrophic fungus fruiting on rotten wood of Arbutus (Pacific Madrone, Ericaceae) typically in hollowed bases of large trees, sometimes damaged by fire, in mixed forest of Pseudotsuga, Arbutus or Quercus; distributed along coastal areas of British Columbia on sites with large mature Arbutus trees, south to Marin County, California, possibly elsewhere along the coast where mature Arbutus occur. The type was collected from a burned stump at the California-Oregon state line.
Since the habitat is exclusive to hollowed bases of large Arbutus menziesii trees and the hollowing is most often created by forest fires, then the habitat for T. punicea is certain to decline as Arbutus forests fall to development and forest fire is suppressed. Decline of A. menziesii has been reported over the past 40 years in the Pacific Northwest due to urbanization, fire suppression, and also disease (Elliott, 1995, Elliott, 2002, McGregor et.al. 2016). The pathogen Neofusicoccum arbuti is particularly well-documented as a cause of death and decline of stressed Arbutus trees McGregor et at, 2016, and the pathogen weakens the ability of the tree to store reserves in its burls, this preventing vigorous regeneration after fire or other catastrophic events.
Preservation of habitat containing host trees and preserve individual large Arbutus menziesii trees in British Columbia to help stabilize this potentially declining population
Further targeting of sites with large Arbutus for determination of additional confirmed collection sites.
Although this species is currently known from coastal areas of British Columbia south to Marin County, California, further searches of likely habitat may reveal whether it is more widespread, especially at inland areas in large arbutus stands.
Adams, A.B. and Hamilton, C.W. (Eds.), 1995. The decline of Pacific madrone (Arbutus menziesii Pursh): current theory and research directions. Proceedings of the April 28, 1995 Symposium held at the Center for Urban Horticulture, University of Washington, 146 p.
Elliot, M.E. 1999. The Decline of Pacific Madrone (Arbutus menziesii Pursh) in urban and natural environments: Its causes and management. MS thesis. University of Washington. College of Forest Resources.
Elliott, M.E., Edmonds, R.L., Mayer, S. 2002. Role of fungal diseases in decline of Pacific madrone. Northwest Science. 76(4): 293-303
Matheny, P.B., Vellinga, E.C., Bougher ,N.L., Ceska, O,, Moreau, P.A., Neves, M.A.,and Ammirati, J.F. (2007) Taxonomy of displaced species of Tubaria. Mycologia 99(4): 569-585.
McGregor, R.R., Sakalidis, M. &. Hamelin, R.C. 2016. Neofusicoccum arbuti: A hidden threat to Arbutus menziesii characterized by widespread latent infections and a broad host range. Canadian Journal of Plant Pathology, 38:1, 70-81.
Mushroom Observer. http://mushroomobserver.org/