During this evaluation it was possible to correct one record erroneously attributed to the USA (MICH herbarium and attributed to C.G. Lloyd). Corrected record here > http://mycoportal.org/portal/collections/individual/index.php?occid=350450 )
Amanita torrendii is a typically Mediterranean species that occurs only in the Mediterranean and sub-mediterranean forests and shrublands in sandy soils. It is ectomycorrhizal, primarily with Quercus suber. The conservation status of its most common habitat is reported by the EU Habitat Directive as “Unfavourable-Bad” due to changes in area, structure and function (habitat quality), and future prospects. According to the IUCN Red List, the population of Q. suber, the species’ main host, is also decreasing. The population size of the species is estimated as 10,000-15,000. It is assessed as NT under the C1 criterion due to the size of the population and past and continuing decline of habitat and main host.
Synonym: Torrendia pulchella Bres.
Amanita torrendii was originally described as Torrendia pulchella by Bresadola (1902). Justo et al. (2010) transferred it to Amanita section Caesareae based on molecular data.
Amanita torrendii has so far been recorded in six countries in Europe (Spain, Portugal, France, Italy, Greece, and Cyprus), two countries in Africa (in the Atlas Mountains in Morocco and Algeria), and one in Asia (Turkey), a typical distribution around the Mediterranean Sea. The southern limit of distribution is unclear due to a lack of data (e.g. a single historical occurrence in Sierra Leone from 1905 by G. Malecón in GBIF). It is uncertain if the species occurs in other areas of Africa along the Mediterranean.
In Europe, A. torrendii is confined to the Mediterranean region and its most common habitat is Quercus suber (cork oak) forests (Natura 2000 habitat type 9330). The number of known sites for Amanita torrendii was about 100 in 2015, most in the Iberian Peninsula with only seven in France (including three in Corsica), and four in Italy (of which three in Sardinia) (Fraiture and Otto 2015). There are currently 210 records of the species in GBIF, approximately 155 are from Spain, and 33 are from Portugal; the number of records from the other countries is much lower (GBIF 2021). While the size of the suitable habitat throughout the region is large, the concentration of the host Quercus suber primarily is restricted to the Iberian Peninsula. There are an estimated 1000 - 1500 sites throughout its range, each with up to 10 mature individuals per site, giving a total population size of 10,000-15,000.
The conservation status of Q. suber forests is ‘Unfavourable-Bad’ (based on data from Spain and Portugal) due to changes in area, structure and functions (habitat quality), and future prospects (European Environment Agency, 2013-2018). This lower status in comparison with the previous assessment period (2007-2012; ‘Unfavourable-Inadequate’) indicates the ongoing decline of this type of habitat in the stronghold of the species. According to the IUCN Red List, the population of Quercus suber, the species’ main host, is also decreasing (Barstow and Harvey-Brown 2017). As a whole, the Mediterranean basin is subject to many pressures (FAO and Plan Bleu 2018). With a growing population and a climate that is expected to become drier and warmer, the pressure on Mediterranean forests is enormous. Direct causes of decline include the conversion of forests to fire-prone shrub communities, outbreaks of pests and pathogens, and increased forest fires.
Population Trend: Decreasing
Amanita torrendii is a typically Mediterranean species that occurs only in the Mediterranean and sub-mediterranean forests and shrublands in sandy soils. It is ectomycorrhizal with Quercus spp. (especially Q. suber), Pinus spp. (P. pinaster and P. pinea), Cistus spp. (C. monspeliensis and C. salvifolius) and, possibly, also with Castanea sativa. The species occurs in the following NATURA 2000 habitats (codes): 2180, 2270, 9230, 9260, 9330 (Quercus suber forests, the most common habitat), 9340, and 9540 (Dahlberg and Croneborg 2003).
The species is threatened by forest cutting and loss of habitat connectivity, and the modification of semi-natural woodlands management regimes, e.g. overgrazing. Climate change is a growing concern, with increased wildfires, pervasive drought stress and diseases affecting the species’ main host, Quercus suber (Barstow and Harvey-Brown 2017).
About half of the localities are part of the Natura 2000 network and hence thought protected, but appropriate management, e.g. preventing overgrazing, reducing fire frequency, etc. is needed. Protection from habitat changes outside of the Natura 2000 network is also needed.
Additional information on distribution and host preference is needed, especially from Africa.
Alfredo Justo, Ingo Morgenstern, Heather E. Hallen-Adams & David S. Hibbett (2010). Convergent evolution of sequestrate forms in Amanita under Mediterranean climate conditions. Mycologia 102: 675-688.
Bresadola G. 1902. Mycetes Lusitanici novi. Atti Imp. Regia Accad. Rovereto, ser. 3, 8:132.
Fraiture A. & Otto P. (eds) 2015. Distribution, ecology and status of 51 macromycetes in Europe. Results of the ECCF Mapping Programme. Scripta Botanica Belgica 53, Botanic Garden Meise.
Dahlberg A. & Croneborg H. (2003). 33 threatened fungi in Europe. Complementary and revised information on candidates for listing in Appendix I of the Bern Convention. A document compiled for EU DG Environment and the Bern Convention by Anders Dahlberg
and Hjalmar Croneborg at the Swedish Species Information Centre on behalf of the Swedish Environmental Protection Agency (EPA) and the European Council for Conservation of Fungi (ECCF).