Synonyms: Amanita brunneolocularis var. pallida N. Vargas, (2017)
Amanita brunneolocularis is a distinctive and conspicuous macrofungus, discovered in the 1986 and formally described in 1992 on the basis of material from Colombia (Holotype HUA, Ovrebo 2506)
Sometimes this specie can be misidentified as A. rubescens, however the spores in A. rubescens differ from those in A. brunneolocularis by being more ellipsoidal (Q’ = 1.4) (Tulloss 2002), whereas in A. brunneolocularis they are globose to subglobose; the pileus is white at first (Tulloss 2002) to cream with bronze stains in A. rubescens and grayish yellow to light orange (but not white) in young or mature specimens in A. brunneolocularis; the universal veil in A. rubescens is pale yellow to cream, and pale cream to pink in A. brunneolocularis (Vargas et al., 2017)
The species is associated to mountain oak forests in Colombia, Costa Rica and Honduras. There are not enough information about the trend of the population of A. brunneolocularis, however, habitat loss and degradation are the main threatened. Tropical forests dominated by oak are restricted to mountain areas with anthropic pressures due to land use change, deforestation, timber extraction causing a decrease in populations, fragmentation and loss of habitat quality.
The species has been reported for Colombia in the departments of Antioquia (Vasco-Palacios & Franco 2013), Boyacá (Vargas et al. 2017), Valle del Cauca (Soto-Medina & Bolaños-Rojas 2013) and Tolima (Murillo). In Panama it has been reported for the Chiriquí province, in the Fortuna Forest Reserve (Corrales and Ovrebo, 2020). In Costa Rica in the provinces of San José and Cartago (Tulloss et al. 2011) and in Honduras (Tulloss 2009d) in the department of Olancho. Although this species has also been reported for the United States of America in the state of North Carolina (Tulloss et al., 2011), this is the only record for the whole country and it was found in association with an unusual host (Pinus strobus). For those reasons it is unlikely that this record is part of this species natural distribution given that A. brunneolocularis has generally been associated with Quercus spp.
The extent of occurrence (EOO) of this species is estimated to be 327998 km², based on the polygon formed by the known localities, and the area of occupancy (AOO) is estimated to be 96 km². Considering the ability of this species to form ectomycorrhizas with Quercus, it is likely that this species occurs in other Central American countries where this host plant is found.
This species has currently been reported for four countries: Colombia, Panamá, Costa Rica and Honduras. There are 53 known collections of this species, with the largest number of records present in Colombia. In Colombia many specimens have been collected in the department of Antioquia (municipality of Belmira, Medellín (Santa elena), El Retiro, Santa Rosa de Osos), Tolima (municipality of Murillo), Boyacá (municipality of San Miguel de Sema, Villa de Leyva and Arcabuco) and Valle del Cauca (hamlet of Chicoral). In Panama, the only known record is from the Fortuna Forest Reserve in the Chiriqui province. In Costa Rica there are 20 records distributed in two provinces, San José (Perez Zeledón, San Gerardo de Dota) and Cartago (Cañón, Empalme). The only records from Honduras is from the department of Olancho (La Tigra Natural Park).
There is no direct information suggesting that the population of A. brunneolocularis has declined. However, a significant decline is inferred due to the extensive past and ongoing habitat loss and decline in habitat quality.
The subpopulations present in Colombia are associated with Quercus humboldtii, a host species found in the Andes mountain range of Colombia. Nevertheless, this ecosystem is highly threatened. In 1990, these oak forests covered a total of 1.210.000 hectares. However, by 2015 this coverage fell to 530.000 hectares. Due to this fact, this ecosystem became one of the most affected by deforestation (Velásquez 2018). Expansion of the agricultural frontier is the factor that is causing the greatest alteration and degradation of this habitat. The opening of new paddocks, through a gradual and almost imperceptible process has highly contributed to this problem. (Avella 2016). Which means that almost 42% of Quercus humboltii populations have undergone an intense process of decline, which makes oak trees been located in the vulnerable category (VU A2cd) for Colombia (Cárdenas & Salinas 2007), and listed as LC globally (Gallagher 2018). A loss of its mycorrhizal host directly impacts A. brunneolocularis and it is estimated that the species has undergone rapid population decline in the past and that will continue into the future resulting in a population decline of between 30-50% in Colombia.
Costa Rica is the second country with the most records of the species, where most of them are located within the Private Biological Reserve of the Hotel de Montaña Savegre, which reduces the threats for these forests and in consequence for the species Amanita brunneolocularis. However, this species likely occurs throughout the country and has not yet been reported. Although less data is available to predict the decline of the species in Costa Rica, parts of the Talamancas are known to be protected in national parks, but other areas are privately owned and there is ongoing limited logging, as well as commercial and housing developments. For the mountainous areas where this species is found, the total forest cover has not changed significantly in the last 20 years (MINAE 2018).
Honduras only has one record in La Tigra National Park, but the presence of species is possible in more areas of the territory, since its relationship with oak trees allows us to deduce that it is present in a large part of the tropical montane cloud forests of this country. Although these forests are an important part of the National System of Protected Areas of Honduras (SINAPH) (Padilla 2003), for 2001, 417,600 hectares of this forest were registered, of which only 103,200 hectares were in protected areas (Brown & Kappelle 2001). Deforestation in Honduras is one of the highest in the world, it is estimated that 35,000 to 85,000 ha of forest are deforested each year in the country and it is estimated that the forests have suffered a rapid decrease in the past and that they will continue in the future, resulting in a decrease of the population in the future of between 30-35% in Honduras (DiBio 2017).
There is less data available to predict the decline of the species in Panama and the species is present the in the Fortuna Forest Reserve (Corrales and Ovrebo 2020). As A. brunneolocularis is ectomycorrhizal and requires a Quercus host, a decline in host population directly negatively impacts its population size, although the sites in Costa Rica are relatively stable, the sites in Colombia, Panama and Honduras will continue to face significant threats and continued decline
Population Trend: Decreasing
Amanita brunneolocularis is an ectomycorrhizal mushroom associated with different species of Quercus. It grows in tropical montane forest, associated with Quercus humboldtii in Colombia, Quercus copeyensis in Costa Rica and Quercus insignis in Honduras. In Panama, Corrales and Ovrebo (2020) reported that this species could be associated with Quercus sp. or Oreomunnea mexicana (Juglandaceae)
The main known threat to Amanita brunneolocularis is declining habitat and fragmentation due to deforestation and the decrease of populations of Quercus species. In Colombia, around 40% of the territory has been transformed due to population increase and changes in land use (Avella & Rangel 2017). In the Andean region, deforestation has transformed at least 60% of the areas original ecosystem, and have significantly reduced the area of Quercus humboldtti forests (Avella & Rangel 2017). Anthropogenic pressure on oak forests and habitat degradation is mainly due to deforestation due to land use change, logging, and urbanization. In addition, timber extraction carried out for the production of charcoal in the past and continued use of wood for construction of houses and furniture has significantly negatively impacted oak populations (Cárdenas & Salinas 2007, Nieto & Rodriguez 2010). There are several large mining initiatives being considered for the region, and if they come to fruition they will have a significant negative impact. There has been nearly 42% loss of Quercus humboldtii populations, and the tree is listed as vulnerable (VU A2cd) in Colombia (Cardenas & Salinas 2007). Deforestation in Colombia has increased in recent years and is anticipated to continue into the future.
Furthermore, it is estimated that the forests of Honduras have the highest deforestation rates in the world, according to the National Commissioner for Human Rights (CONADEH 2016), between 34,000 and 58,000 ha are lost annually due to deforestation, to illegal logging and other inadequate forest management practices (TRAGSATEC 2016), putting the populations of A. brunneolocularis present in this country at risk.
Although due to a policy aimed at conserving the remaining natural areas, there is a lower level of threat to the species in Costa Rica (MINAE 2018).
Regarding the main threats to Panama forests, according to the EPANB the greatest threat is due to the land-use change. From 2001 to 2018, Panama lost 380 kha of tree cover, which is equivalent to a 6.7% decrease in tree cover since 2000 (GFW 2020)
Habitat protection and management are needed mostly in Colombia, Panama and Honduras.
Quercus humboldtii, occur at several protected sites for Colombia, , including the slopes of Nevados del Puracé and Huila, Parque Nacional Darién, Los Guacharos National Park, Corredor de Conservación de Robles Guantiva – La Rusia – Iguaque, and biological reserves on private land (Cárdenas & Salinas 2007). Quercus populations in Panama are restricted to few montane forest in the north west and Darien areas. For Honduras, it is found in reserve areas such as La Muralla National Park, Sierra de Agalta National Park, La Montaña Celaque National Park, Montecillos Biological Reserve, Güisayote Biological Reserve, and Guajiquiro Biological Reserve (Padilla 2003). However, most of the habitat in these countries is not protected and is susceptible to deforestation or degradation. Fungi are not included in conservation and biodiversity policy and laws
To understand a little more the distribution patterns of this species, it would be necessary to promote mycological expeditions in reserve areas where the presence of oaks has been detected, since the most conserved areas could reflect the status of this species to a greater extent. This accompanied by morphological and molecular analyzes, are needed for phylogenetic inference and to provide identified sequences that allow the identification of samples, clarifying various ecological aspects (for example, possible hosts other than Quercus)
A taxonomic review of the collections deposited in the herbaria should be carried out, given the similarities of this species with other Amanita species.
Tullos (2009d) mentions that no uses are reported for this species, but it should be expected to be poisonous if eaten raw. However, Soto-Medina and Bolaños-Rojas (2013) mention that A. brunneolocularis has edible potential, but does not taste good.