Assessment Notes

Justification

Mycobonia brunneoleuca is a rare species of white-rot fungus, growing in neotropical forests restricted to montane environments, like Araucaria and cloud forests in Brazil, Colombia, Costa Rica, Honduras, Martinique, Panamá, Paraguay, Puerto Rico, and Venezuela. There are 16 collections of M. brunneoleuca known and it is estimated to occur in 1,000 to 2,000 sites with up to 10 mature individuals at each, resulting in a population of 10,000-20,000 mature individuals. Due mainly to climate change and deforestation of cloud forests in the Neotropics, the population is expected to be declining by at least 35-50% in the next 30 years. Thus the species is assessed as Vulnerable A3c.

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Geographic range

Mycobonia brunneoleuca is distributed in cloud forests and Araucaria forests at c.700–2,700 m asl. in Neotropical regions in Brazil (Gerlach and Loguercio-Leite 2011), Colombia, Costa Rica, Honduras (Nakasone 2015), Martinique (Burt 1919), Panamá (Martin 1939), Paraguay, Puerto Rico (Nakasone 2015), and Venezuela (type locality).

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Population and Trends

Mycobonia brunneoleuca's population can be considered to be divided into two subpopulations, one in cloud forest in northern tropical America, and the second in southern South America. There are only 16 collections of M. brunneoleuca, five found in Costa Rica, three in Brazil, and the remaining collections were found one in each of the following countries/territories: Colombia, Honduras, Martinique, Panamá, Paraguay, Puerto Rico and Venezuela. Mycobonia brunneoleuca is expected to be distributed elsewhere in the Neotropical forests, likely restricted to cloud forest and montane environments. Based on the extent of potential appropriate habitat, the species could occur in up to 1,000-2,000 additional sites, each site supporting 10 mature individuals resulting in an estimation of 10,000-20,000 mature individuals. 

Recent studies suggest that in 25 to 45 years, decreasing cloud immersion will reduce or dry up 57% to 80% of the neotropical cloud forest, including Mexico, Central America, the Caribbean, much of northern South America, and parts of southeastern Brazil (Helmer et al. 2019). Also Araucaria forests are suffering a continuing decline (Global Forest Watch 2020). Only a small part of the Araucaria forests are in conservation areas (Indrusiak and Monteiro 2009), and studies suggest that, due to climate change, by 2070 the species could be restricted to highland microrefugia, of which only 2.5% are in conservation areas (Wilson et al. 2019, Castro et al. 2020). Considering the expected loss of habitat, the population is inferred to be declining at least 35-50% in the next 30 years (three generations).

Population Trend: decreasing

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Habitat and Ecology

Mycobonia brunneoleuca is a rare and saprotrophic species causing white-rot on dead wood. Basidiomes are found solitary and it is only known from neotropical Araucaria and cloud forests, between 700 and 2,700 m asl.

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Threats

Araucaria and cloud forests are particularly susceptible to deforestation and climate change (Bubb et al. 2004). Cloud forests are restricted and dependent on rare microclimatic conditions (Mulligan et al. 2010, Oliveira et al. 2014), making it one of the most susceptible ecosystems to threats caused by climate change (Salazar et al. 2007, Williams et al. 2007, Goldsmith et al. 2013, Gotsch et al. 2014, Pompeu et al. 2014). The most widely recorded threat to cloud forests, and therefore to the species, is the conversion to agricultural land or pine and Eucalyptus plantations. Other important threats are conversion to grazing land, hunting, fire, timber harvesting, fuelwood harvesting, roads, mining, and deforestation for drug cultivation (Bubb et al. 2004).

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Conservation Actions

Protection of the species' habitat, neotropical cloud forest and Araucaria forest, by the establishment and management of conservation units should be considered at regional and local levels. Additional surveys and collections are needed, as well as information about host specificity. Further research should be conducted into its taxonomy, population size, distribution and trends, its ecology, and its potential for use as an edible species.

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Use and Trade

It is not currently used, but potential for its use should be researched.

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Source and Citation

Palacio, M., Westphalen, M., Gomez-Montoya, N., Benjumea, C., Alves-Silva, G., Martins da Cunha, K., Kossmann, T., Costa-Rezende, D.H., Trierveiler-Pereira, L., Baltazar, J.M., Vieira de Miranda, M. & Drechsler-Santos, E.R. 2022. Mycobonia brunneoleuca. The IUCN Red List of Threatened Species 2022: e.T209595073A209596310. https://dx.doi.org/10.2305/IUCN.UK.2022-1.RLTS.T209595073A209596310.en .Accessed on 5 August 2024

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• Country occurrence