Endemic to North America. Fevesia aurantica is an easily recognized hypogeous mycorrhizal fungus associated with old growth subalpine to alpine habitat containing Abies amabilis, A. lasiocarpa, A. magnifica var. shastensis, and Tsuga mertensiana. It is only known from 12 collections; eight from Oregon, three from Colorado and one from Idaho (the population is severely fragmented). Random Grid survey of 750 plots for two years across this region, including plots in this habitat type, did not reveal any new collections or sites for this species (area of occupancy is 480 km2). The total population is not considered to exceed 10 times higher number of sites. Harvest of mature and old-growth Abies forests potentially hosting F. aurantica are inferred to have caused and continue to cause habitat loss and degradation affecting the total population. In addition, these montane forests are subject to intense forest fires and disturbance from human activities. Climate change is potentially devastating to these high elevation mountain forests in western North America. This species therefore qualifies for listing as Endangered.
It is listed as a sensitive species by the USDA Forest Service and the Bureau of Land Management in Oregon (Cushman and Huff 2007). Ranked as Critically Imperiled (G1 S1) on the Global and National rankings by the Heritage Program (NatureServe 2015).
Restricted to USA in California, Oregon, Idaho, and Colorado. with 12 known collections, (sites), eight from Cascade Mountains of Oregon, three from Rocky Mountains of Colorado and one from Bitterroot Mountains of Idaho.Random Grid survey of 750 plots for two years across this region, including plots in this habitat type, did not reveal any new collections or sites for this species (Castellano 2007). Of the known sites, two are historic and not re-documented for over 30 years. One recent known site has been destroyed by forest fire.
Population size: the 12 known extant sites x5 mycelia = 60 potential mature individuals (see Dahlberg and Mueller 2001). The number of yet unknown sites is not considered to exceed 10, hence the total number of mature individuals not to exceed 600.
Population Trend: decreasing
This is a mycorrhizal fungus species so it is dependent on living host trees for population viability. This mutually beneficial, symbiotic association between fungus and plant host roots conveys numerous critical advantages for plant host survival. Mycorrhizal fungi are essentially the uptake organs for many nutrients i.e., nitrogen, phosphorus, numerous micronutrients, i.e., boron, selenium, copper, and plays a major role in uptake of water. Both the fungus and the plant host does not exist in nature without each other.
Fevesia aurantica is a hypogeous, mycorrhizal fungus associated with old growth forests of Abies amabilis, A. lasiocarpa, A. magnifica var. shastensis, and Tsuga mertensiana at 1,700-2,700 m elevation. Characterized by its sequestrate form, sticky, gelatinous, pink to orange gleba with gel-filled chambers (Castellano et al. 1999, Trappe and Castellano 2000). Fruiting from August through October. Dispersal is dependent on mycophagy (Castellano et al. 1999, Trappe and Castellano 2000). Home range of primary spore vector (small mammals) is less than 2 ha.
Fevansia aurantiaca is a mycorrhizal fungus species so it is dependent on living host trees for population viability. Mature and old-growth Abies forests are routinely harvested for wood products that has led to some forest fragmentation that impedes fungus dispersal and gene flow. In addition, these montane forests are subject to intense forest fires (from dry lightening storms in dry summer months), and disturbance from human activities, i.e. trail head development and trial construction, road building, home construction, and campground development. Global climate change is potentially devastating to high elevation mountain forests in western North America which are characterized by heavy snow pack in winter and cool summers.
Protect known sites and buffer known sites from ground and host disturbances. Mitigate impacts during vegetation management in or near known sites.