Assessment Notes

Justification

This species has an estimated population size of around 700-7,000 mature individuals, in small subpopulations of no more than 50 mature individuals, along with a continuing decline in population size. It is, therefore, precautionarily assessed as Endangered C2a(i).

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Geographic range

This species is found from the Maule region to Los Rios region, Chile. It range spans from the coast to the foothills of the Andes. Based on the currently known records, the extent of occurrence is 43,558 km². The area of occupancy is quoted in the Chilean national assessment as 500 km², however, this is based on using a 10x10 km grid over the collection locality data.

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Population and Trends

There are seven collections in Chile from five localities, and it is estimated to occur in no more than 50-500 localities taking into account those yet unknown. Its present extent covers Maule, Bio Bio, Araucanía and Los Rios regions, with uncertain presence in Los Lagos region. It is restricted to Chile and is not present in Argentina. Based on the currently known records, the seven collections represent 70 ramets (mature individuals) at five localities. Assuming it is present in 10-100 times as many localities, the population size is estimated as 700-7,000 mature individuals, comprised of small subpopulations of no more than 50 mature individuals. A continuing decline in the population size is inferred based on a continuing decline in the area of available habitat, through forest loss and burning.

Population Trend: decreasing

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Habitat and Ecology

The basidiome is robust, growing singly or in small groups scattered in soil and litter under Nothofagus (i.e. N. obliqua, N. dombeyi and N. glauca). It reaches up to 1,350 m of altitude. It is the largest and most robust of the four native Chilean species of Russula. It is distinguished by a fishy or rubbery smell. It forms basidiomes in autumn-winter.

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Threats

The major threats to this species are associated with the reduction of its habitat, i.e. the deforestation of native forests covering the species' range. There is a latent danger from excessive deforestation in its area of distribution, where the habitat is already fragmented. In addition fire is a major threat, as these small native forest patches are surrounded by dense pine plantations which are deliberately burned.

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Conservation Actions

There are no conservation actions currently in place for this species, though it is nationally assessed as Vulnerable in Chile under B2ab(iii). The most important conservation action required is fire prevention, and the best way of achieving this would be to put firebreak clearings around the native forest patches. Additionally, better understanding of the ecology of the species is needed; and population genetics studies are also required.

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Use and Trade

This species is not used or traded.

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Source and Citation

Furci, G. 2021. Russula austrodelica. The IUCN Red List of Threatened Species 2021: e.T75124171A196462976. https://dx.doi.org/10.2305/IUCN.UK.2021-1.RLTS.T75124171A196462976.en .Accessed on 14 April 2023

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• Country occurrence