Assessment Notes

Justification

Although it is currently only known from a few sites, this species appears to be very common, with a likely population size significantly exceeding the thresholds for the threatened categories under Criterion D and probably Criterion C. There is no reason to suspect any past, current, or immediate future population declines and, therefore, it would not qualify for a threatened category under Criterion A. As this species' spores are dispersed by air and rain, it is less likely to be restricted in distribution than species relying on an animal vector, and it could be widespread, so even though it is currently only known from a limited number of sites, it is not appropriate to assess it as threatened under Criterion B. It is therefore assessed as Least Concern.

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Taxonomic notes

Pseudotulostoma volvatum was originally described as P. volvata. The second species currently in the genus (P. japonicum) occurs in Japan (Asai et al. 2004). Phylogenetic analyses indicate these taxa are nested within Elaphomyces (Masuya and Asai 2004, Reynolds 2011, Castellano et al. 2016), which may require them to be reclassified as Elaphomyces.

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Geographic range

This species occurs at two sites in Guyana: Region 8, Potaro-Siparuni: Pakaraima Mountains, 1) Upper Ireng River, 3 km east of mouth of Sukabi River, toe slopes of Mt. Kukuinang alt. 800 m, under Dicymbe corymbosa. 2) Upper Potaro River, south bank, 3 km upstream from Ayanganna airstrip, alt. 750 m, under D. corymbosa.
It has also been collected in Colombia under Pseudomonotes tropnebosii in terra-firme forests, in Amazonia (A. Vasco-Palacios unpublished data).

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Population and Trends

It occurs frequently at one of its known localities in Guyana, being one of the most frequently occurring species, found in 27.6% of subplots in a survey of above-ground ECM fungi in a 3-ha plot conducted over 7 years (Henkel et al. 2012).

The population at the currently known sites in Guyana is likely to be significantly in excess of 1,000 mature individuals: this is based on a plot survey which counted an average of 96 ascomata per year (Henkel et al. 2012), each of which represent 2 ramets, though it is unclear what percentage of these will be the same individuals counted in multiple years. This 3-ha plot is only a small proportion of the potential habitat available at the site, and it is very likely to also be found in other sites. There is no reason to suspect any significant population decline at the currently known sites.

Population Trend: unknown

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Habitat and Ecology

Henkel et al. (2012) used morphological and molecular analysis to demonstrate that Pseudotulostoma volvatum forms ectomycorrhizal symbioses with Dicymbe corymbosa. In Colombia it has been collected under Pseudomonotes tropenbosii (Dipterocarpaceae) in terra-firme forests, in Amazonia (A. Vasco-Palacios unpublished data).

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Threats

Current threats include climate change and small-scale mineral extraction that can cause habitat disturbance and water pollution, although these threats are currently not thought to be severe as much of the interior of the region is very remote (pers. obs. and M. Smith pers. comm.). Future threats from timber and mineral extraction, and land use changes are anticipated, with the potential for these to be rapid if further road construction occurs (M. Smith pers. comm.). Further impacts of climate change, particularly droughts, are also anticipated.

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Conservation Actions

No conservation actions are currently in place for this species, but protection of its habitat is needed. Additional survey work to document the species' distribution and abundance, taxonomy, and life history are needed. Gene sequence data could be used to aid in such surveys.

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Use and Trade

There are no known uses of this species.

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Source and Citation

Dentinger, B. 2020. Pseudotulostoma volvatum. The IUCN Red List of Threatened Species 2020: e.T172832924A172861392. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T172832924A172861392.en .Accessed on 2 February 2024

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• Country occurrence