R-L categories correct, but text here does not match final assessment. Updated version will be published in IUCN´s Red List June or Nov 2019.
Amanita friabilis is a small ectomycorrhizal species that associates exclusively with Alnus spp. (A. glutinosa, A. incana, A. viridis), in wet to temporarily flooded biotopes in Europe, mainly in the boreal, continental and alps regions. The species is reported to have been declining in several countries. Its hosts, in the genus Alnus, have been undergoing deterioration across Europe due to disease (e.g. Phytophtora alni). The conservation status of its most common habitat has been reported as “unfavourable-bad” in the same regions where A. friabilis mainly occurs, meaning the habitat is in serious risk of becoming regionally extinct.
Red-listed as near threatened under criteria A2c+A3c because of past and future decline of habitat.
Synonyms: Amanitopsis vaginata * friabilis P. Karst. and
Amanitopsis friabilis (P. Karst.) Sacc.
Widespread in Europe, but occurring mainly in Boreal, Continental, and Alpine regions. Also reported in Turkey, in western Siberia (single record) and the western Caucasus.
The species is widespread in Europe, but mainly occurs in the Boreal, Continental and Alpine regions. It is rarer in the Atlantic region and very rare in the Mediterranean region. By 2015 the number of known sites in Europe was estimated at about 100. Outside Europe, it is apparently very very rare (e.g. one single record in Western Siberia).
The most common habitat of Amanita friabilis is “Alluvial forests with Alnus glutinosa and Fraxinus excelsior “(Natural 2000 code 91E0). According to the last report under Article 17 of the EU Habitats Directive (European Environmental Agency, 2007-2012), the conservation status of this habitat is “unfavourable-inadequate” in Black Sea, Mediterranean and Pannonian regions and “unfavourable-bad” in the Alpine, Atlantic, Boreal, and Continental regions, meaning the habitat is in serious risk of becoming extinct (at least regionally), precisely in the regions where A. friabilis occurs predominantly. Decline is expected as the future trend was assessed as negative in all regions except the Black Sea and Continental (stable) and Mediterranean (unknown) regions.
Populations of Alnus, the hosts of A. friabilis, have been deteriorating, as a result of pest damage and disease, for example, A. viridis in the Alps where the fungus Valsa oxystoma was considered the primary fungus involved, and A. glutinosa across Europe (by the oomycete Phytophtora alni), now reported in ten countries posing a serious threat to the species; note that trees growing on riverbanks or flood plains are particularly vulnerable since the presence of water appears to facilitate the transport of the pathogen.
The species is considered Extinct in The Netherlands and is RedListed in several European countries: e.g. Austria (EN), Czech Republic (EN), Estonia (VU), Sweden (NT).
Population Trend: Decreasing
Amanita friabilis is ectomycorrhizal exclusively with Alnus spp. (A. glutinosa, A. incana, A. viridis) in forests, groves and bushes in wet to temporarily flooded biotopes. It is restricted to wet soils and tolerates temporary flooding. In Europe, the species occurs in the following NATURA 2000 habitats (codes): 6310, 9010, 9050, 9080, 91E0 (“Alluvial forests with Alnus glutinosa and Fraxinus excelsior”; the most common habitat).
Among main threats belong hydrological changes in water level and regulation of watercourses. Changes in forest management & use and invasive alien species are also pointed out as threats.
European member states indicated four conservation actions: Establish protected areas/sites, adapt forest management, restoring/improving forest habitats, and restoring/improving the hydrological regime.
The species is not known to be used.
Romagnesi H. (1992) Bull. Soc. Mycol. France 108(2) : 78
Corriol G. (1999) Bull. Soc. Mycol. France 115(2) : 205