Stropharia acanthocystis was described by Cortez & Silveira in 2007.
Stropharia acanthocystis is a mushroom species from the Araucaria Moist Forests of Southern Brazil, a very fragile habitat that is estimated to have declined about 97% and is projected to further decline in the future.
It is assessed as VU under criterion C2a(ii).
The species is currently known from São Francisco de Paula National Forest, in Rio Grande do Sul state, and Rio do Peixe City Park in Joaçaba, Santa Catarina state, both in Southern Brazil, in the Araucaria Moist Forests of the Atlantic Forest domain.
It is expected to be found throughout the Araucaria Moist Forests in Southern Brazil and a small part of northern Misiones, Argentina.
Stropharia acanthocystis is currently known only from two sites, with 10 records. It is likely a rare species, as it is conspicuous and there are few records even in well surveyed areas in its potential range, with only 10 specimens being found in over 10 years since its description.
The habitat where the species is found has declined by about 97%, with the remaining areas heavily fragmented, with over 80% of the fragments with less than 50 ha, and surrounded by farming lands, which have been shown to hold a smaller diversity than larger forests, and with signs of disturbance (Ribeiro et al. 2009, Souza et al. 2012, Nodari et al. 2016).
Total population is estimated at no more than 10.000 mature individuals, distributed in around 250 sites, each with up to 40 mature individuals. Between 2001 and 2018, there has been a liquid cover loss of approximately 3.1% (13% loss and 9.9% gain) (Global Forest Watch 2020). However, in chronically disturbed areas, the Araucaria Moist Forests are kept at early successional stages, which may not hold the appropriate conditions to support species from pristine fungal communities, such as S. acanthocystis.
It is assessed as VU under criterion C2a(ii).
Population Trend: Decreasing
Stropharia acanthocystis is a saprotrophic mushroom found on dead angiosperm wood and less frequently on soil in Araucaria Moist Forests.
The species is threatened by habitat loss, mainly due to logging, fire and conversion of forests into farming lands. The Araucaria Moist Forests have lost about 97% of their original extent, with 80% of the remaining area being composed by fragments under 50 ha inside of private farms and surrounded by crop fields and grasslands, and largely disturbed. Only 3.1% of the remaining habitat is in protected areas, which corresponds to 0,09% of the orginal Araucaria Moist Forests range.
The Araucaria Moist Forests are restricted to higher altitude regions with subtropical climates, with high year-long precipitation, cold winters and temperate summers. Studies have shown that by 2070, Araucaria angustifolia, the dominant tree of the AMF, will likely be restricted to highland microrefugia as an impact of climate change. This means that the structure of the AMF can be drastically different, or that the AMF itself will also be restricted to these areas.
The main action to preserve the species is the protection of its habitat, restoration of Araucaria Moist Forests, and creation of new conservation areas to harbor the probable microhabitats to which the AMF may be restricted in the future. Also, measures must be taken to assure that the protected AMF areas reach a mature state.
More surveys are needed in other areas to confirm the species range, including its association with mature forestal conditions. Also, there are no DNA sequences available for the species, and no phylogenetic studies have been conducted to test its phylogenetic position.
Brooks, T., Balmford, A. (1996) Atlantic forest extinctions. Nature 380: 115.
Castro, M.B., Barbosa, A.C.M.C., Pompeu, P.V. et al. (2020) Will the emblematic southern conifer Araucaria angustifolia survive to climate change in Brazil?. Biodivers Conserv 29, 591–607. https://doi.org/10.1007/s10531-019-01900-x
Cortez, V.G., Silveira, R.M.B. (2007) A new species of Stropharia with hymenial acanthocytes. Mycologia, 99(1): 135–138. doi:10.1080/15572536.2007.11832609
Cortez, V.G., Silveira, R.M.B. (2008) The agaric genus Stropharia (Strophariaceae, Agaricales) in Rio Grande do Sul State, Brazil. Fungal Diversity 32: 31-57
Fundação SOS Mata Atlântica (2009) Atlas dos remanescentes florestais da Mata 822 Atlântica, período 2005 2008. Relatório Final. São Paulo. Fundação SOS Mata 823 Atlântica/Instituto Nacional de Pesquisas Espaciais
Global Forest Watch. 2020. World Resources Institute. Accessed in 20 April 2020. http://www.globalforestwatch.org/
Indrusiak, C., Monteiro S. (2009) Unidades de Conservação na área de distribuição da Araucária. In: Fonseca CR, Souza AF, Leal-Zanchet AM, Dutra TL, Backes A, Ganade G (eds) Floresta com Araucária: ecologia, conservação e desenvolvimento sustentável. Holos, Ribeirão Preto, pp 253–265
Myers, N., Mittermeier, R.A., Mittermeier, C.G., Fonseca, G.A., Kent, J. (2000) Biodiversity hotspots for conservation priorities. Nature 403(6772): 853-858.
Nodari, E. S. (2016) Historia de la devastación del Bosque de Araucaria en el sur del Brasil. Areas: Revista Internacional de Ciencias Sociales 35:75–85. http://revistas.um.es/areas/article/view/279171
Pinto, L.P., Bede, L.C., Paese, A., Fonseca, M., Paglia, A.P., Lamas, I. (2006) Mata Atlântica brasileira: Os desafios para a conservação da biodiversidade de um hotspot mundial. In: Rocha, C.F.D., Bergallo, H.G., Sluys, M.V., Alves, M.A.S. Biologia da conservação: Essências (ed. 1). Rima Editora. 91-118.
Ribeiro, M. C., Metzger, J. P., Martensen, A. C., Ponzoni, F. J., & Hirota, M. M. (2009) The Brazilian Atlantic Forest: How much is left, and how is the remaining forest distributed? Implications for conservation. Biological Conservation, 142(6), 1141–1153. doi:10.1016/j.biocon.2009.02.021
Salazar, L.F., Nobre, C.A., Oyama, M.D. (2007) Climate change consequences on the biome distribution in tropical South America. Geophysical Research Letters 34(9).
Seger, C. (2016) Revisão Taxonômica do Gênero Stropharia Sensu Lato (Agaricales) no Sul do Brasil (MSc Thesis) Universidade Federal do Paraná, Curitiba, Paraná, Brazil.
Sevegnani, L., Vibrans, A.C., Gasper, A.L. (2013) Considerações finais sobre a Floresta Ombrófila Mista em Santa Catarina. In: Vibrans, A.C., Sevegnani, L., Gasper, A.L., Lingner, D.V. (eds) Inventário Florístico Florestal de Santa Catarina Volume III: Floresta Ombrófila Mista. Edifurb, Blumenau. 275-278.
Silva, P. S., Cortez, V. G., & da Silveira, R. M. B. (2009) New species of Stropharia from Araucaria angustifolia forests of southern Brazil. Mycologia, 101(4): 539–544. doi:10.3852/08-097
Souza, A. F., Cortez, L. S. R. & Longhi, S. J. (2012) Native forest management in subtropical South America: long-term effects of logging and multiple-use on forest structure and diversity. Biodivers Conserv 21, 1953–1969 https://doi.org/10.1007/s10531-012-0287-1
Tabarelli. M., Fonseca G.A., Mittermeier, R.A. (2018) From hotspot to hopespot: An opportunity for the Brazilian Atlantic Forest. Perspectives in Ecology and Conservation. Perspectives in Ecology and Conservation 16(4): 208-214.
Vibrans, A.C., McRoberts, R.E., Lingner, D.V. et al. (2013) Extensão original e Remanescentes da Floresta Ombrófila Mista em Santa Catarina. In: Vibrans, A.C., Sevegnani, L., Gasper, A.L., Lingner, D.V. (eds) Inventário Florístico Florestal de Santa 1057 Catarina Volume III: Floresta Ombrófila Mista. Edifurb, Blumenau, pp 25 31
Wilson, O.J., Walters, R.J., Mayle, F.E., Lingner, D.V., Vibrans, A.C. (2019) Cold spot microrefugia hold the key to survival for Brazil’s Critically Endangered Araucaria tree. Glob Change Biol. 25: 4339– 4351. https://doi.org/10.1111/gcb.14755