Assessment Notes

Justification

This conspicuous Amauroderma species is known from only three disjunct sites in Brazil. However, it is expected to occur over a wider area. Despite this it is likely to be rare, given how other Amauroderma species are more commonly found. In total the population size is estimated to be in the range 4,000-8,000 mature individuals, split into multiple subpopulations. A continuing decline in population size is inferred to be occurring as there has been extensive habitat loss and degradation in areas of its range. Therefore, A. renidens is listed as Vulnerable under criterion C2a(i).

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Geographic range

The species is currently known from three disjunct sites in Brazil. It has been found in Santa Catarina state in Blumenau municipality (Bresadola 1896, type locality), and in Bahia state in Gongogi municipality (Torrend 1940, Góes-Neto 1999), both in the Atlantic Rain Forest domain. The third record is from Rio Negro municipality, Mato Grosso do Sul State, in a private property (Fazenda Santa Emília), in the southern part of the Pantanal domain, very close to the Cerrado domain (Bononi et al. 2008). The species likely occurs also in the Cerrado domain. The known sites of occurrence are very distant from each other, with approximately 1,800 km between Rio Negro and Gongogi, and 1,050 km between Blumenau and Rio Negro.

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Population and Trends

The known sites of Amauroderma renidens represent only 3 records across 2 different phytogeographic domains in Brazil, the Atlantic Forest and Pantanal. The species likely occurs also in the Cerrado domain, but has not been recorded. The known records exhibit a disjunct distribution. In areas that have been intensively sampled, the species is rarely encountered and the assumption is that it is rare throughout its range. Because of the large area of potential suitable habitat, around 1,000 sites of occurrence are estimated. Also, considering its rarity, each site is estimated to contain only 4-8 mature individuals. Total population size is estimated at 4,000-8,000 mature individuals, split into multiple subpopulations, none of which would contain >1,000 mature individuals.

Although the Pantanal and the Cerrado are ecosystems with a largely understudied Funga, the Atlantic Forest has the longest mycological history in the country, and several studies on the diversity and taxonomy of macrofungi have been carried in the domain, especially in southern Brazil. Other Amauroderma spp. are found regularly throughout this range, so the scarcity of records of A. renidens is likely due to the rarity of this conspicuous polypore. 

Nevertheless, the number of sites could be smaller than estimated, as areas where the species has been found in Atlantic Forest have been historically deforested, and this domain has only 28% of its original coverage remaining, mainly composed by forest fragments (Myers 2000, Tabarelli et al. 2010, Rezende et al. 2018). Although the Pantanal is a considerably better-preserved ecosystem in Brazil, the accumulated deforestation in the biome is almost 20%, with an average of 0.33% habitat loss per year in recent years (Silva et al. 2011, SOS Pantanal 2017). The Cerrado has lost over half of its more than 2 million square kilometers, mainly in the last 50 years (Rocha et al. 2011, INPE 2020). Most of this habitat loss happened in the southern parts of the Cerrado, closer to where the species is known to occur. The deforestation rates in the biome has decreased in the last decade, stabilizing to 0.33% per year in 2018 and 2019 (INPE 2020), but are expected to increase due to current political trends of loosening environmental policies and legislation. On top of that, only 8.3% of the Cerrado’s area is currently under protection in conservation units (Françoso et al. 2015).

Overall, due to the past and ongoing decline in its habitat cover and quality, the species' population decline is suspected to be at least of 10% in the next 20 years.

Population Trend: decreasing

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Habitat and Ecology

This species is saprobic, wood-decomposer causing white-rot on dead wood, occurring in the Atlantic Forest and Pantanal domains. Also, it is expected that the species occurs in the Cerrado domain.

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Threats

In general, the threats to Amauroderma renidens are the degradation and fragmentation of its habitat, mainly related to loss of territory for agriculture, such as soybeans and large scale cattle ranching, growth of urban areas, fires and continuous secondary effects of previous deforestation, such as climate change, “secondarization” and “savannization” (Tabarelli et al. 2010, Scarano and Ceotto 2015, Alho et al. 2019). Possibly, some of the sites where the species has been recorded no longer exist as natural areas.

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Conservation Actions

The main actions required to preserve the species are the implementation of conservation units and the enforcement of protection policies, in order to preserve its habitat and prevent further loss. Additionally, more surveys in unexplored areas, such as the Cerrado and other areas of the Pantanal, are needed to understand the distribution and ecology of the species.

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Use and Trade

No use or trade is known.

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Source and Citation

Robledo, G., Drechsler-Santos, E.R., Kossmann, T., Bittencourt, F., Rezende, D. & da Cunha, K.M. 2020. Amauroderma renidens. The IUCN Red List of Threatened Species 2020: e.T187000558A187004585. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T187000558A187004585.en .Accessed on 21 February 2024

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• Country occurrence