Lactifluus hallingii is endemic to southern neotropical montane oak forest ecosystems (Costa Rica, Panama, and Colombia) found at altitudes ranging from 1,900 to 2,900 m asl. The species is an obligate ectomycorrhizal fungus with neotropical Quercus, including Q. costaricensis, Q. seemannii and Q. humboldtii. Lactifluus hallingii can be solitary or found in large patches of basidiocarps, and it has been commonly encountered at the sites where it has been reported. A loss of its mycorrhizal hosts directly impacts L. hallingii. Additionally, there is evidence of replacement of native mycorrhizal fungi on the roots of Quercus by exotic species, including Amanita muscaria, that were introduced with pines. In Colombia and Panama, it is estimated that L. hallingii has undergone rapid population decline in the past and the decline will continue into the future resulting in a population reduction of between 30-50%. As many of the sites in Costa Rica are protected, it is inferred that the species is relatively stable there. Based on past, ongoing and future inferred population reduction in Colombia and Panama, the ongoing reduction for the population of Lactifluus hallingii is suspected to be between 25-35% over three generations. It is precautionarily listed as Vulnerable.
Lactifluus hallingii is a recently described species from Panamanian material that is also widely distributed in Colombia and Costa Rica (Delgat et al. 2019). Specimens of this species had been previously been identified as Lactarius deceptivus Peck originally described from North America and could be considered a cryptic species.
Lactifluus hallingii is a conspicuous neotropical milk cap. The species is associated to mountain oak forests in Costa Rica, Panama, and Colombia. There are not enough information about the trend of the population of L. hallingii. However, habitat loss and degradation are the main threatened. Tropical forests dominated by Quercus 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.
Lactifluus hallingii is an ectomycorrhizal fungus associated with Quercus species in Costa Rica, Panama, and Colombia. This species was recently described from material from wet montane forest in Cerro Punta (Chiriquí province, Panama). The species has also been reported in Colombia, in the departments of Antioquia, Boyacá, Santander, and Tolima (Vasco-Palacios and Franco-Molano 2013, Peña-Venegas and Vasco-Palacios 2019, Vargas and Restrepo 2019). In Costa Rica it is associate with Quercus seemannii and Q. copeyensis in the Cordillera Talamanca.
Lactifluus hallingii is known from Quercus dominated forests in Colombia, Panama, and Costa Rica. In Panama it is only known from the type locality in Chiriqui province. In Colombia the species forms ectomycorrhizas with Quercus humboldtii in Antioquia, Boyacá, Santander, and Tolima departments. There are over 130 Colombian herbarium specimens collected from at least 21 different localities (identified as Lactarius deceptivus). Those collections are housed in herbaria at the University of Antioquia (HUA) and at Universidad de los Andes (ANDES). Its host tree has a wider distribution in Colombia, and L. hallingii likely occurs in other localities around the country. There are collections of Costa Rican material in the University of Costa Rica (USJ), Costa Rican National Museum (CR), and New York Botanical Garden (NYBG). In Panama L. hallingii is only known from 1 herbarium collection from a site where it was associated with Quercus costaricensis and Q. seemannii (Delgat et al. 2019).
There is no direct information that the 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 decline in its mycorrhizal hosts, species of Quercus. Further pressure and population reductions are expected to continue. There has been a nearly 42% loss of Quercus humboldtii populations in Colombia, and the tree is listed nationally as vulnerable (VU A2cd) (Cardenas and Salinas 2007). Deforestation in Colombia has increased in recent years and is anticipated to continue into the future. In Panama, Quercus species are mostly found in the mountainous areas in the provinces of Chiriquí and Darien. Little data are available regarding population trends of the oak forests of Panama; however, a report published in 2019 by the National Ministry of Environment (MiAMBIENTE 2019 ) documents that about 50% of the total forest cover of the country has been lost since 1950. This report also states that deforestation rates have been increasing in the country during the last years with an annual deforestation rate of 11.415 ha/year between 2000 and 2012. Forests in Costa Rican sections 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, the total forest cover has not significantly changed in the last 20 years (MINAE et al. 2018).
A loss of its mycorrhizal hosts directly impacts L. hallingii. Additionally, there is evidence of replacement of native mycorrhizal fungi on the roots of Quercus by exotic species, including Amanita muscaria, that were introduced with pines (Vargas et al. 2019). In Colombia, it is estimated that L. hallingii has undergone rapid population decline in the past and this will continue into the future resulting in a population decline of between 30-50%. Based on the documented loss of habitat in Panama, a loss of up to 50% is inferred for that country. As many of the sites in Costa Rica are protected, it is inferred that the species is relatively stable there. Based on past, ongoing and future estimated population declines in Colombia and Panama, the ongoing decline for the overall population of L. hallingii is suspected to be between 25-35%.
Population Trend: Decreasing
Lactifluus hallingii inhabits southern neotropical montane forest ecosystems dominated by oaks, in an altitude range ranging from 1,900 to 2,900 m asl. (Vasco-Palacios and Franco-Molano 2013, Delgat et al. 2019). The species is obligatorily ectomycorrhizal with neotropical Quercus, including Q. costaricensis, Q. seemannii and Q. humboldtii. Lactifluus hallingii can be solitary or found in large patches of basidiocarps (Franco-Molano et al. 2000, Delgat et al. 2019) and it has been commonly encountered at the sites where it has been reported.
The main known threat to Lactifluus hallingii is habitat loss and fragmentation due to deforestation resulting in population decline of Quercus, its mycorrhyzal host. 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 and Salinas 2007, Nieto and Rodriguez 2010). In Colombia there are several large mining initiatives being considered for areas where the species occurs, and if they come to fruition they will have a significant negative impact. Deforestation in Colombia and Panama has increased in recent years and is anticipated to continue into the future. Due to a policy aimed at conserving remaining natural areas, there is a lower threat level for the species in Costa Rica (MINAE et al. 2018). In addition to loss of mycorrhizal host, there is evidence of replacement of native mycorrhizal fungi on the roots of Quercus by exotic species, including Amanita muscaria, that were introduced with pines (Vargas et al. 2019).
Habitat protection and enhanced forest management are needed in Panama and Colombia. Quercus populations in Panama are restricted to a few montane forest in the north west and Darien areas. In Colombia, the host tree, Quercus humboldtii, occurs in several protected sites, 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 and Salinas 2007). But most of the habitat is unprotected and susceptible to deforestation or degradation. Fungi are not included in Colombian conservation and biodiversity policy and laws.
Research is needed to evaluate population trends and further document distribution. 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 the Colombian and Costa Rican herbaria should be carried out, as this is a cryptic species that was previously treated as Lactarius deceptivus.
It is probably edible (Franco-Molano et al. 2000, Peña-Cañón and Henao-Mejia 2014) given that the closely related species, Lactarius deceptivus, is used widely for food in other parts of the world. L. hallingii is starting to be marketed as an edible in some Colombian cities.