Assessment Notes

Justification

The species is known from 3 small sites with an estimated total number of sites being up to 8. Sixteen mature individuals are thought to occur at the known sites, which would equate to a total of 43 mature individuals. As the sites occur near villages of indigenous peoples who practice shifting agriculture, the sites are threatened due to potential future disturbance. The species is listed as Critically Endangered.

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Taxonomic notes

Austroboletus amazonicus A.M. Vasco-Pal. & C. López-Quint. was described as new species by Vasco-Palacios et al. (2014).

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Geographic range

This species has a limited range, in association with its host, Pseudomonotes tropenbosii, Dipterocarpaceae (Vasco-Palacios et al. 2014). Specimens of Austroboletus amazonicus have been collected in three sites of the Amazon region: El Zafire Biological area, in the southern part of the Colombian Amazon, 27 km north of Leticia in the Amazonas Department; about 50 km downstream along the Rio Caqueta from Araracuara near Peña Roja, and close to the village of Puerto Santander, both at 200–300 m.

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Population and Trends

Austroboletus amazonicus appears to be rare, restricted to terra firme forests dominated by the endemic host tree Pseudomonotes tropenbosii (Dipterocarpaceae). The distribution of this species is restricted. Currently, A. amazonicus has been collected 13 times, at three sites distributed in two subpopulations. However, based on its symbiosis with Pseudomonotes tropenbosii, it is estimated that it also occurs in five more places were this tree has been reported. There are an estimated 16 mature individuals from the known sites, and it is predicted that the other five sites of suitable habitat have a similar number of mature individuals giving an estimated total number of mature individuals of 43.

Population Trend: unknown

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Habitat and Ecology

The species has been recorded from three sites of the Colombian Amazon in mycorrhizal association with Pseudomonotes tropenbosii (Vasco-Palacios et al. 2014). Pseudomonotes tropenbosii (Dipterocarpaceae) is an endemic tree species from Colombia. This tree grows in a patchy distribution in terra-firme forests. At present, only a few patches of P. tropenbosii have been reported, and the most extensive area does not occupy more than four hectares. These patches are located in the southern part of the Colombian Amazon, where the mean temperature is approximately 26°C, and the relative humidity is about 86%. Mean monthly precipitation is 280 mm, with a drier period between June-September and a rainy season between October-May. Soils in this area are sandy and mainly composed by quartz. The elevation in these areas is 80-300 m.

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Threats

Austroboletus amazonicus is restricted to 3-8 small sites associated with patches of Pseudomonotes tropenbosii. These site are close to indigenous villages. In this region, indigenous peoples use the terra-firme forests to establish chagras or farming areas. Although chagras are about 1 ha. they could destroy entire patches of species host, Pseudomonotes tropenbosii. Also, this region is being negatively impact from illegal mining (Forest 500 initiative).

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Conservation Actions

No conservation actions are currently in place for this species. Protection of habitat is needed, which would also entail informing the local population about the importance of these sites and enforcing policy on land use. Continuing the exploration of the region is also needed.

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Source and Citation

Vasco-Palacios, A.M., Calle, A., Drechsler-Santos, E.R., Kossmann, T., da Cunha, K.M. & TEHO Group 2020. Austroboletus amazonicus. The IUCN Red List of Threatened Species 2020: e.T75098759A179542191. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T75098759A179542191.en .Accessed on 2 February 2024

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• Country occurrence