Assessment Notes

Justification

Phylloporia minuta is a small parasitic polypore. It was described in 2018 after specimens collected in an urban protected area of Atlantic Forest, southern Brazil, growing on stems of a climbing plant, Doliocarpus schottianus Eichler. It was found again in 2019, on the same host, in another preserved forest area next to the urban area of other municipality, in Santa Catarina state. It is expected that it is a specific parasite of D. schottianus. The known and expected distribution is covered by Atlantic Forest, which is under threat from deforestation, amongst other threats. More research on neotropical polypores is needed to confirm the potential distribution of this species, its biology and the magnitude of the population trend. However, with the population size estimated at 8,000 mature individuals, Phylloporia minuta is assessed as Vunerable (VU) under criterion C2a(ii).

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Taxonomic notes

Phylloporia minuta was described by Bittencourt et al. (2018) based on specimens collected in Blumenau, southern Brazil. Currently, the species has no synonyms. Its epithet refers to the very small size of its basidiomata.

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Geographic range

Phylloporia minuta is a parasitic species so far known to grow exclusively on Doliocarpus schottianus, an endemic climbing plant of the coastal Atlantic Forest of southern-southeastern Brazil. It is currently known from a small urban protected area in the downtown of Blumenau municipality and in an experimental area of the University of Joinville municipality, both in Santa Catarina State, southern Brazil. Its distribution is expected to match that of its host’s, spanning around 1,300 km in a linear distribution across the southern and south-eastern coastal Atlantic Forest, from Santa Catarina state to Espirito Santo state, being endemic to this area. The core of its population is expected to be found between northern Santa Catarina and the south of São Paulo, where its host is most commonly found, with fewer sites throughout northern São Paulo, Rio de Janeiro and Espírito Santo states, where there are few records of D. schottianus.

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Population and Trends

The species is currently known from 2 sites and 11 collections. Its basidiomata are very small (<20 mm), and are found on living stems of climbing plants. The small size and its occurrence on an overlooked substrate for polypores are the probable reasons why it has only been recently described, despite the areas where it is known from being historically well sampled. The species' inconspicuousness makes it difficult to find, meaning that it could be more common than the current paucity of collections may suggest.

Its distribution is expected to match that of its host’s, spanning around 1,300 km in a linear distribution across the southern and south-eastern coastal Atlantic Forest, from Santa Catarina to Espírito Santo states, being endemic to this area. Its host, Doliocarpus schottianus, is usually found in climatic, humid forests of the coastal Atlantic Forest, especially close to water streams, but also secondary forest fragments. The habitat where it is usually found is now much rarer than it was in the past, as the Atlantic Forest has been reduced to less than 28% of what it once was, with the remaining areas being mostly fragmented and not fully mature (Rezende et al. 2018). This suggests that in the past the species was probably much more abundant, with its population now being just a fraction of what it once was. Despite the large longitudinal range, there are an estimated 100 sites of occurrence along its host’s distribution, as it is expected to be restricted to humid areas, with sites mostly concentrated between northern Santa Catarina and southern São Paulo, where its host is most commonly found, and fewer sites throughout northern São Paulo, Rio de Janeiro and Espírito Santo, where there are few records of D. schottianus. Each site is estimated to contain up to 80 mature individuals. Total population size is estimated at no more than 8,000 mature individuals.

Population Trend: decreasing

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Habitat and Ecology

The species is an obligate parasite, growing on young stems of Doliocarpus schottianus, a climbing plant (Bittencourt et al. 2018) endemic to the southern-southeastern coastal Atlantic Forest in humid areas. According to Kubitzki and Reitz (1971), D. schottianus is a selective hygrophyte and sciophyte, frequent in the interior of primary forests. The fungus is expected to occur along its host's distribution, also being endemic to the coastal Atlantic Forest.

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Threats

Phylloporia minuta is found in the coastal Atlantic Forest of Brazil, regarded as a biodiversity hotspot for conservation priorities due to its high diversity, endemism rates and habitat loss (Myers et al. 2000). This phytogeographical domain is estimated to have only 28% of vegetation remaining (Rezende et al. 2018). According to Pinto et al. (2006), the Atlantic Forest is found in this situation due to predatory exploitation of resources and territorial occupation. Over 60% of the Brazilian population lives in the Atlantic Forest, mainly in coastal areas, where the country’s largest cities are located (Rezende et al. 2018). Other threats to the Atlantic Forest include an increase in fire frequency and intensity, introduction of invasive species and the connection between these factors (Brooks and Balmford 1996, Tabarelli et al. 2004, Pinto et al. 2006). Also, a reduction and ‘savannization’ of Atlantic Forest is expected due to climate change in the next decades (Salazar et al. 2007). The only two sites where P. minuta specimens were found are protected areas very close to urban areas, and other unprotected sites are possibly threatened with illegal land occupation, fire, exotic species , pollution and other anthropogenic activities.

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Conservation Actions

The main actions to prevent the decline of the species are the protection of its habitat by the implementation of conservation areas and enforcement of public policies to recover secondary forests. Also, further research work should be conducted. The conservation status of the host plant species should be assessed, while more surveys are needed to better understand the species' distribution, as well as to confirm its host specificity and its phenology. Also, research regarding its host conservation, such as potential threats and its conservation status are needed.

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Use and Trade

No use/trade is known.

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Source and Citation

Bittencourt, F., Kossmann, T., Martins da Cunha, K., Leopoldo, E., Gumboski, E.L. & Drechsler-Santos, E. 2021. Phylloporia minuta. The IUCN Red List of Threatened Species 2021: e.T196135686A198498944. https://dx.doi.org/10.2305/IUCN.UK.2021-2.RLTS.T196135686A198498944.en .Accessed on 2 October 2024

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• Country occurrence