Assessment Notes

Justification

The distribution of this species is limited to Nothofagus forests, which are under constant pressure for logging and agricultural activities. It has so far only been found in three sites, of which one has been lost, leaving two sites which represent two locations. Given its large conspicuous nature, and the intensive surveying which has been carried out to find further occurrences, even though there may be further unrecorded sites it is precautionarily assumed that there will still be fewer than five locations. With an EOO of under 5000 km², and AOO of under 500 km², and continuing decline in the extent and quality of its habitat, it therefore qualifies as Endangered B1ab(iii)+2ab(iii).

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Geographic range

Its distribution is limited to the coastal zone of the Bio Bio and Los Lagos regions in southern Chile. Only three sites are known, one of which (the type locality) appears to have been lost due to habitat destruction: the area is now a pine plantation and the fungus has been searched for and not refound. Its EOO based on the three known sites (including the destroyed one) is 3,633 km² (it is reasonable to include the destroyed site in this calculation as the species may be present in further sites in the same areas). Its AOO is estimated as 300 km² based on the total sizes of forest patches within this area.

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Population and Trends

It has only been recorded at three sites. Its population size and trend are unknown, but it can be assumed to be in decline based on the extensive and ongoing forest fragmentation within this region.

Population Trend: decreasing

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Habitat and Ecology

This ectomycorrhizal species grows individually or in small scattered groups half buried in soil under native forest of Nothofagus (i.e. N. obliqua, N dombeyi). Its distribution reaches 770 m altitude. It is distinctive in form and colour, and is the only known species of secotioid boletes in South America. It forms sporulating bodies in autumn.

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Threats

The major threat is the decline in quality and changing land use of native forest where this species is found. Despite being a striking fungus, it has only been recorded three times in 30 years. There is a latent threat from excessive forest fragmentation in its area of distribution. Fire is another threat: in the last five years fire has affected the northern part of its distribution and this is likely to reoccur.

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Conservation Actions

There are no conservation actions currently in place for this species. Increasing the search effort around the known sites and in other likely localities is necessary to find further occurrences of this species.

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Use and Trade

This species is not utilized.

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Source and Citation

Furci, G. 2019. Gastroboletus valdivianus. The IUCN Red List of Threatened Species 2019: e.T75110094A75110098. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T75110094A75110098.en .Accessed on 3 February 2025

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• Country occurrence