Assessment Notes

Justification

This species occurs in the Valdivian forest of Argentina and Chile, and is restricted to forest with Saxegothaea conspicua. The species is suspected to be in decline, but there is not strong evidence for this. Overall the population size is estimated to be  small (500-900 mature individuals), but could potentially be larger. Precautionarily, this species is listed as Vulnerable under criterion D1.

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Geographic range

This species occurs in temperate forests (Valdivian forests) of Argentina and Chile. It is restricted to forest with Saxegothaea conspicua.

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Population and Trends

The species' host is in decline due to forest fragmentation and fires, and this species is suspected to be decreasing in line with the decrease of it's host population. The species is severely fragmented within its range, potentially found in small clusters of <10 mature individuals. Assuming that the number of sites where this species may occur in the wider habitat could be up to 5-10 times more than the number of known sites, the total population size of this species is estimated to be between 500-900 mature individuals.

Population Trend: Decreasing

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Habitat and Ecology

This species grows on the bark of living Saxegothaea conspicua trees.

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Threats

The host, Saxegothaea conspicua, is restricted in distribution and confined to national parks in Argentina, where it can be impacted by tourism activities and fire events. In Chile conversion of native forest in the coastal Cordillera to commercial plantations of Pinus radiata and Eucalyptus means that much of the habitat for this species has been lost and continues to disappear.

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Conservation Actions

Some subpopulations are known from protected areas. Protection of habitat and the host species is vitally important for this species. Raising awareness of this species and its host, in order to reduce the impacts of tourism activities, could be beneficial. Research into the population size, distribution and trends of this species would be beneficial, in particular investigating whether it may occur in more coastal areas of Chile, because at the moment it is only known from Andean parts of the Valdivian forest.

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Use and Trade

There is no use/trade of this species.

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Source and Citation

Greslebin, A., Kuhar, F., Pfister, D. & Truong, C. 2020. Uncobasidium roseocremeum. The IUCN Red List of Threatened Species 2020: e.T172779245A172861282. Accessed on 24 November 2025.

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• Country occurrence