Amanita ballerina is an easily identifiable Amanita species. It has recently been described from northern Thailand, although Amanita had been relatively intensively studied in nearby areas (mostly Yunnan, China; e.g., Yang 2005, Yang 2014, Yang 2015, Cai et al. 2016), and more broadly in SE Asia (e.g., Boedijn 1951, Corner & Bas 1962). The species is currently known from only two localities in Chiang Mai Province, northern Thailand, where it grows under Dipterocarp-dominated or Fagaceae-dominated forests, depending on elevation and form ectomycorrhizal association with yet to be determined tree species, belonging to Dipterocarpaceae and/or Fagaceae trees. Forest cover in northern Thailand was reduced by more than 75 % between 1915 and 1995, mostly because of conversion to cropland (Delang, 2002). The same trend was observed in nearby areas of the Greater Mekong Subregion (WWF, 2015). Despite some conservation efforts (through the creation of National Parks), forests in northern Thailand are still under threat from human activities such as recurrent burning and understorey tea or coffee plantation. Therefore, the species is inferred to be rare, declining, and under threat by deforestation and forest degradation.

Amanita ballerina is an easily identifiable Amanita species. It has recently been described from northern Thailand, although Amanita had been relatively intensively studied in nearby areas (mostly Yunnan, China; e.g., Yang 2005, Yang 2014, Yang 2015, Cai et al. 2016), and more broadly in SE Asia (e.g., Boedijn 1951, Corner & Bas 1962). The species is currently known from only two localities in Chiang Mai Province, northern Thailand, where it grows under Dipterocarp-dominated or Fagaceae-dominated forests, depending on elevation. Forest cover in northern Thailand was reduced by more than 75 % between 1915 and 1995, mostly because of conversion to cropland (Delang, 2002). The same trend was observed in nearby areas of the Greater Mekong Subregion (WWF, 2015). Despite some conservation efforts (through the creation of National Parks), forests in northern Thailand are still under threat from human activities such as recurrent burning and understorey tea or coffee plantation. Therefore, the species is inferred to be rare, and under threat by deforestation and forest degradation.

Known only from two localities in Chiang Mai Province, Northern Thailand (Thongbai et al. 2017; O. Raspé pers. obs.).

Known only from two localities in Chiang Mai Province, Northern Thailand (Thongbai et al. 2017; O. Raspé pers. obs.). In Doi Suthep-Pui National Park, the species has been found in three different sites at elevations between 740 m and 1170 m, but at each site, only 1 or 2 individuals were observed. So the subpopulation in Doi Suthep-Pui National Park is estimated to be below 200 . The size of the other known subpopulation is lower. We estimate the total population to be under 10,000, with a maximum of 50 subpopulations, each subpopulation harbouring less than 200 individuals.
Forest cover in northern Thailand was reduced by more than 75 % between 1915 and 1995, mostly because of conversion to cropland (Delang, 2002). The same trend was observed in nearby areas of the Greater Mekong Subregion (WWF, 2015). Despite some conservation efforts (through the creation of National Parks), forests in northern Thailand are still under threat from human activities such as recurrent burning and understorey tea or coffee plantation.  Because Amanita ballerina is an ectomycorrhizal species found in Dipterocarp-dominated forests, it is inferred that the species has declined and is still under threat by deforestation and forest degradation.

The species has been observed both in semi-deciduous forest dominated by Dipterocarpaceae and evergreen hill forests dominated by Fagaceae. It is ectomycorrhizal, but the ectomycorrhizal tree species with which it associates is (are) not known.

Forests cover in Northern Thailand was reduced by more than 75 % between 1915 and 1995, mostly because of conversion to cropland (Delang, 2002). The same trend was observed in nearby areas of the Greater Mekong Subregion (WWF, 2015). Despite protection measures and reforestation, Thailand lost 7.8 % of Intact Forest Landscapes between 2000 and 2013 (Potapov et al 2017). In the area where Amanita ballerina is known to occur, forests continue to be degraded by human activities (e.g., understorey tea or coffee plantation, recurrent burning).

There is no species-specific actions, but National Parks have been created in northern Thailand, beginning in 1962 (http://www.thainationalparks.com). The number and area of forests under protection should be increased. Burning of forested areas and understorey plantation of tea and coffee should be better controlled/limited.

The distribution needs to be better known. The ectomycorrhizal symbiotic partners should be identified.

No use known.

Boedijn KB (1951) Notes on Indonesian fungi. The genus Amanita. Sydowia 5: 317-327.

Cai Q, Cui YY & Yang ZL (2016) Lethal Amanita species in China. Mycologia, 108(5): 993–1009.

Corner EJH & Bas C 1962. The genus Amanita in Singapore and Malaya. Persoonia 2: 241–304.

Delang CO (2002) Deforestation in Northern Thailand: the result of Hmong swidden farming practices or Thai Development Strategies? Society and Natural Resources 15 (6): 483-501.

Potapov P, Hansen MC, Laestadius L, et al. (2017) The last frontiers of wilderness: Tracking loss of intact forest landscapes from 2000 to 2013. Science Advances 3: e1600821. https://doi.org/10.1126/sciadv.1600821

Thongbai B, Miller SL, Stadler M, Wittstein K, Hyde KD, Lumyong S, et al. (2017) Study of three interesting Amanita species from Thailand: Morphology, multiple-gene phylogeny and toxin analysis. PLoS ONE 12(8): e0182131. https://doi.org/10.1371/journal.pone.0182131

WWF (2015) WWF living forest report: chapter 5. Saving forests at risk.

Yang ZL (2005) Flora Fungorum Sinicorum. Vol. 27. Amanitaceae. Beijing: Science Press. 258 p.

Yang ZL (2015) Atlas of the Chinese Species of Amanitaceae. Beijing: Science Press. 213 p.