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 caesarea is a common, widespread, and well-known edible ectomycorrhizal mushroom typically associating with oaks and other hardwood species in a variety of habitats from the Mediterranean and the Black Sea basins. Although red-listed in many European countries, A. caesarea doesn’t meet any of the criteria for a threatened category on a global scale. It has a large distribution and host breadth and there is no evidence of large-scale population decline. It can be locally very abundant where suitable habitat exists. Therefore, it is assessed as Least Concern (LC).
With a bright orange cap and yellow stem, provided with a ring and a volva, Amanita caesarea is an unmistakable fungus. It is a common and widespread edible ectomycorrhizal species from the Mediterranean and the Black Sea basins but has been declining for the last decades in some countries of occurrence and threats to its habitat (mostly related to forestry and airborne nitrogen deposition) have been identified. It is nationally red-listed in many European countries (Albania, Austria, Bulgaria, Czech Republic, France (regional RedList), Germany, Hungary, Montenegro, Poland, Russia (regional RedList), Serbia, Slovakia, Switzerland and Ukraine and protected by law in some (Croatia, Czech Republic, Germany, Serbia, Slovakia, Slovenia and Ukraine).
The species has its native distribution range around the Mediterranean and the Black Sea basins. It is known from northern Africa (Algeria, Morroco, Tunisia), the southern part of Europe (absent from The Netherlands, Poland, UK and Scandinavia), the Caucasus region (Georgia, Turkey), Ukraine, Crimea and the Russian Caucasus, mostly Krasnodar Kray (Svetasheva, personal communication). Contrary to some reports, a comprehensive study by Sánchez-Ramírez et al. (2015) showed that the species does not occur in North or Central America nor in East Asia.
Amanita caesarea has been reported from more than 500 sites in Europe (2015) and the total number, including yet unrecorded sites, is estimated to be at least a 10-fold higher. In Europe, reported population trends diverge: while the species is nationally red-listed in many countries of occurrence based on population decline (e.g. Austria, Switzerland, Bulgaria), some countries reported stable populations (e.g. France, Greece), and Romania and Belgium reported increases (Fraiture & Otto 2015). Population size and trends in northern Africa, Turkey and the Caucasus are unknown. In brief, there is no evidence of population decline on a global scale. The species can be locally abundant where suitable habitat exists. The total number of mature individuals is projected by large to exceed 10 000.
Population Trend: Uncertain
Amanita caesarea is ectomycorrhizal with trees in the Fagaceae, typically Quercus (Q. cerris, frainetto, gussonei, petraea, pubescens, robur, suber, ilex, rotundifolia), but also Carpinus, Fagus and Castanea. Outside the Fagaceae, it is reported to associate with Corylus (Spain), Tilia (Serbia), Abies borisii-regis and A. cephalonica (Greece) and Pinus sylvestris (Germany). It can be found in a variety of habitats, mainly in deciduous to sclerophyllous forests dominated by Quercus, but also other hardwood forests.
Mixed forests (Picea in Romania, Pinus in, e.g., Italy), dehesas (Spain), montados (Portugal), macchia and heaths, both in Italy, as well as extensively managed grasslands with solitary trees (Slovenia) are also suitable habitats.
From lowlands to lower mountain regions.
In Europe, the species occurs in the following Natura 2000 habitats (codes): 4030, 6310, 9110, 9130, 9150, 9160, 9170, 91F0, 91G0, 91H0, 91I0, 91L0, 91M0, 91W0, 91AA, 9230, 9240, 9260, 9270, 9280, 9330, 9340.
Identified threats in Europe mostly relate to forestry (e.g. increased fertilization) and airborne nitrogen deposition. Irresponsible picking has also been reported (Fraiture & Otto 2015).
In Europe, many populations are located within the Natura 2000 network of sites and hence are thought to be protected. The species is nationally red-listed in Albania, Austria, Bulgaria, Czech Republic, France (regional RedList), Germany, Hungary, Montenegro, Poland, Russia (regional RedList), Serbia, Slovakia, Switzerland and Ukraine, and protected by law in some (Croatia, Czech Republic, Germany, Serbia, Slovakia, Slovenia and Ukraine).
One of the most sought-after edible mushrooms in the Mediterranean. Commercially harvested.
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