Assessment Notes

Justification

Cortinarius aurantiobrunneus has only been reported from oak dominated forests in Costa Rica and Colombia. Where it has been found, it is common and occurs in medium to large size patches. In Colombia, the species has only been documented from the department of Santander. In Costa Rica it is documented from the northern part of the Talamanca mountains. Because of challenges in identifying species of Cortinarius, its broader distribution in Colombia, Costa Rica, and possibly Panama is unknown. There is no direct information that the population has declined, but a significant and continued decline is inferred due to extensive past and ongoing loss of its obligate mycorrhizal hosts and decline in habitat quality. As C. aurantiobrunneus is ectomycorrhizal and requires a Quercus host, a decline in host population directly negatively impacts its population size. The ongoing decline for the population of C. aurantiobrunneus is suspected to be between 25-30% over three generations as Quercus humboldtii populations have and continue to undergo significant and continuous loss in Colombia. Therefore, it is listed as Near Threatened.

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Taxonomic notes

The species was described from specimens collected in Costa Rica by Ammirati et al. (2007). The most similar species to Cortinarius aurantiobrunneus is C. limoneus from Europe.

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Geographic range

Cortinarius aurantiobrunneus was described from specimens found in Savegre, Costa Rica at 2,500 m asl. It is also found Colombia, in the Department of Santander- Municipio El Peñón at 2,830 and 2,870 m asl. It probably occurs in other oak forests distributed in Costa Rica and Colombia above 2,500 m asl. In the department of Santander the species occurs in the Municipality El Peñon. El Peñon is part of a large karst massif where caves develop (Lasso et al. 2019). It has not been reported from oak dominated forests in Panama, but it might be found there with additional survey efforts.

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Population and Trends

Cortinarius aurantiobrunneus has only been reported from oak dominated forests in Costa Rica and Colombia. Where it has been found it is common and appears in medium to large size patches. In Colombia, the species has only been documented from the department of Santander and specimens are housed in the ANDES_F fungal collection, Universidad de los Andes. In Costa Rica it is documented from the northern part of the Talamanca mountains. Because of challenges in identifying species of Cortinarius, its broader distribution in Colombia and Costa Rica, and possibly Panama is unknown.  

There is no direct information that its population has declined, but a significant decline is inferred due to extensive past and ongoing habitat loss and decline in habitat quality resulting in a significant reduction in its mycorrhizal host, species of Quercus. In Colombia, there has been a nearly 42% loss of Quercus humboldtii populations, and the tree is nationally listed as vulnerable (VU A2cd) (Cardenas and Salinas 2007). Deforestation in Colombia has increased in recent years and is anticipated to continue into the future. There is less data available to predict the decline of the species in Costa Rica. Parts of the Talamancas are protected in National parks, but other areas are privately held, and there is limited logging ongoing as well as commercial and housing developments. For the mountain areas where this species occurs in Costa Rica, the total forest cover has not significantly changed in the last 20 years (MINAE et al. 2018). As C. aurantiobrunneus is ectomycorrhizal and requires a Quercus host, a decline in host population directly negatively impacts its population size. The ongoing decline for the population of C. aurantiobrunneus is suspected to be between 25-30% over three generations due to its obligate association with Quercus which has and continues to undergo significant and continuous loss in Colombia, the country with the largest potential number of individuals due to its extent of potential habitat.

Population Trend: decreasing

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Habitat and Ecology

Cortinarius aurantiobrunneus is an ectomycorrhizal species associated with neotropical Quercus forests. It is associated with Q. seemannii and Q. copeyensis in Costa Rica and with Q. humboldtii in Colombia.

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Threats

The main known threat to Cortinarius aurantiobrunneus is declining habitat and fragmentation resulting in a significant decrease in populations of neotropical Quercus species. Anthropogenic pressure on oak forests and habitat degradation in Colombia is mainly due to deforestation due to land use change, logging, and urbanization. Due to policies aimed at conserving remaining natural areas, there is a lower threat level for the species in Costa Rica.

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Conservation Actions

Protecting native oak ecosystems and preventing further habitat loss in Colombia is needed. Moreover, encouraging public awareness on the importance of macrofungal diversity and their roles in ecosystems should be a priority for their protection. Survey and inventory efforts are needed to further document its distribution and population trends. Molecular analyses are needed for phylogenetic inference and to provide identified sequences to enable identification of environmental samples required for molecular based ecology studies. A taxonomic review of the collections deposited in Colombian and Costa Rican herbaria should be carried out, as there are many unidentified Cortinarius specimens in the collections.

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Use and Trade

There are no uses of trade of this species.

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Source and Citation

Vargas-Estupiñan, N., Benjumea, C., Corrales, A., Gomez-Montoya, N., Niño Fernandez, Y.M., Peña-Cañón, R., Sanjuan, T. & Vasco-Palacios, A.M. 2020. Cortinarius aurantiobrunneus. The IUCN Red List of Threatened Species 2020: e.T174799358A179541600. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T174799358A179541600.en .Accessed on 3 February 2024

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• Country occurrence