Gyroporus austrobrasiliensis A.C. Magnago, in Magnago, Alves-Silva, Neves & Silveira, Nova Hedwigia 107(3-4): 293 (2018)
It is an endemic species from dense ombrophilous in southern Brazilian Atlantic forest.
Gyroporus austrobrasiliensis is endemic to the Brazilian Atlantic Forest. The Atlantic Forest is unique, highly threatened ecosytem. Gyroporus austrobrasiliensis is known from only three sites, but it is likely to be more widespread occurring in high quality Atlantic Forest areas, with a total population estimate of around 4,500-9,000 mature individuals. Based on the severe habitat decline within the area, we infer a population decline around at least 30% in the last three generations (50 years) and this decline is ongoing. It is assessed as Endangered C1.
The species is currently known from subtropical dense ombrophilous Atlantic Forest in three localities in southern Brazil: at Campeche Island, located in Santa Catarina, 1.6 km from the coast, with an area of 59,2 ha covered mostly by the dense ombrophilous forest; at Refúgio da Vida Silvestre da UFRGS, Morro Santana, an urban reminiscent of the Atlantic Forest, with an area of 1000 ha of which 600 ha are part of the Universidade Federal do Rio Grande do Sul, and at Horto Botânico Irmão Teodoro Luis, this area occupies about 25 ha, and today is located within the Experimental Station Terras Baixas of Embrapa, with a transient vegetation between Pampa and Atlantic Forest, the last two areas cited are located in Rio Grande do Sul state (Magnago et al. 2018). However, many other areas of Atlantic Forest towards north of Brazil have been intensively explored in search of the species, but so far no success, which indicates that the species might be rare.
At the moment there are eleven collections of the species deposited in fungaria. The oldest collection is from the Horto Botânico Irmão Teodoro Luis (RS), from 1960 with only one basidiome. The second collection is from the costal Campeche Island (SC), from 2014, also with just one basidiome in the collection. The other nine collections were made at Morro Santana (RS). All these nine collection were made around the same spot along 2015, 2016 and 2017, and in each collection the number of basidiomes varies between one to four. Except for the first area cited, the other two areas had been part of routine collection expeditions, especially the latter (Morro Santana) was visited monthly for four years (2014-2018). The species has small basidiomes, comparing with other boletoid mushrooms, but are colorful with an orange brown pileus and whitish hymenophore, and easy to identify at species level, with medium to high detectability and after intensively collecting effort along the Atlantic forest the species seems to be rare to find.It is the only Gyroporus species known for the Brazilian Atlantic Forest.
There are three known sites, but the species is expected to be distributed along the dense ombrophilous Atlantic Forest with occurrence up to 500-1000 additional potential sites, each supporting around 9 mature individuals. This gives a total population estimate around 4.500-9.000 mature individuals, restrict to one subpopulation. The longest distance between known collecting sites does not exceed 700 km.
The Atlantic Forest has been deforested over decades, and the remaining fragments are suffering from biomass and biodiversity erosion. The Atlantic Forest is one of the most fragmented tropical/subtropical forests in the world, and only around 28% percent of the original forest in Brazil is left, much of it in small, unconnected fragments (Rezende et al., 2018).
Population decline was estimated in light of extensive loss of suitable habitat (Rezende et al., 2018) and the putative influence that habitat degradation has on species occupation in a given environment (Berglund & Jonsson, 2003; Haddad et al., 2015). Based on this information, we precautionarily assume there has been a habitat loss of at least 30% within the past three generations (50 years) and that this also equates to a population decline of the fungus of at least 30% or more within this timeframe, and this decline is likely continuing into the future.
Population Trend: Decreasing
The species was found in the subropical dense ombrophilous Atlantic Forest of south of Brazil. All the collections were made during the late spring and summer season, in December and January. Many species in this genera are considered to be ectomycorrhizal, but no registers of the possible host are presented for Gyroporus austrobrasiliensis (Magnago et al. 2018).
The extraction of timber, intensive land use including tourism, urban expansion, industrialization and fuelwood harvesting are some of the reasons for deforestation in the Atlantic Forest. Only 28% of its natural coverage remains, largely composed of small forest fragments and secondary forests (Tabarelli et al., 2010; Rezende et al., 2018). Changing temperature and rainfall is causing habitat shifts and alteration. These factors are the biggest threat to the Gyroporus austrobrasiliensis, impacting directly on its habitat and life.
In the three colleting area some efforts have been made, the Campeche Island was declared National Archaeological and Landscape Heritage for its cultural importance. There are marks of very old occupation in the island. The Horto Botânico became an area of Permanent Preservation (APP) regulated in 1964. Since then, trail maintenance, pruning, collection and public visitation is prohibited without authorization. At Morro Santana, part of the 600 ha belonging to UFGRS was designated in 2004 as Nature Conservation Unit Wildlife Refuge (REVIS) with an area of 321.12 ha, however the inspection in this area is still precarious.
The main action to preserve the species is the protection of its habitat and creation of new conservation areas to harbor the probable habitats to which the Atlantic Forest may be restricted in the future. The preservation of pristine forests could be critical for the maintenance of this species, since it has only been found in preserved areas. Also, forest protection policies must be taken to assure that the protected Atlantic Forest areas reach a mature state.
More collections are needed to try to understand the real geographic distribution of the species. The genus is considered ectomycorrhizal, so it is necessary to confirm the mycorrhizal status of the species and study its possible hosts.
Edible, but it is still a species not known among the population.