• Proposed
  • Under Assessment
  • Preliminary Assessed
  • DDAssessed
  • 5Published

Elaphomyces digitatus Castellano, T.W. Henkel & S.L. Mill.

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Scientific name
Elaphomyces digitatus
Author
Castellano, T.W. Henkel & S.L. Mill.
Common names
 
IUCN Specialist Group
Cup-fungi, Truffles and Allies
Kingdom
Fungi
Phylum
Ascomycota
Class
Eurotiomycetes
Order
Eurotiales
Family
Elaphomycetaceae
Assessment status
Assessed
Preliminary Category
DD
Proposed by
Francisca Rodriguez
Assessors
Bryn Dentinger, Matthew Smith
Contributors
Terry Henkel, Francisca Rodriguez
Comments etc.
Janet Scott, James Westrip
Reviewers
David Minter, Maria Alice Neves

Assessment Notes

Justification

This species is known from two sites in Guyana, where a tiny fraction of its possible suitable habitat has been surveyed. It has been found at two of three sites surveyed for it, and so this may be a common and widespread species: potential host plants occur in a large region encompassing parts of Venezuela, northern Brazil and southeast Colombia. However, these sites are in close proximity to each other, and it may be dependent upon an unknown animal vector and potentially restricted. This entire region is very under-sampled, being very remote and completely unsurveyed. In total approximately 0.002% of its potential suitable habitat has been surveyed for fungi. It is not possible to estimate population size or trends, EOO, or AOO. Increasing 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. It is therefore assessed as Data Deficient, and further survey work in this region is urgently needed.


Taxonomic notes


Why suggested for a Global Red List Assessment?

Elaphomyces digitatus is a rare species in lowland forests of the Guyana Shield region. This species should be considered because of its rarity within a narrow geographic region, and its obligate symbiosis with its hosts.


Geographic range

Elaphomyces digitatus is found in the Pakaraima mountains of Guyana within Dicymbe-dominated forests. It has been recorded at two sites, with multiple collections at one site. The first site is in Region 8 Potaro-Siparuni: Pakaraima Mountains, Upper Potaro River Basin, within a 15 km radius of Potaro base camp at 5.30133333, -59.91111111, 710–750 m. Collections here are from the old Ayanganna airstrip, ~200 m south-west of base camp at D. altsonii site; Dicymbe plot 1; vicinity of base camp; Benny’s ridge under D. corymbosa on lateritic ironstone soils; near Tadang base camp in mixed Dicymbe–Aldina forest on lateritic soils and attached directly to roots of A. insignis. The second site is in Region 10 Upper Demarara-Berbice: Mabura Ecological Reserve, field station at 5.15527778, -58.69972222, ~100 m. The collection here was in vicinity of the field station, under D. altsonii on brown sand soils (Castellano et al. 2012).

This entire region is very under-sampled, and there are areas in neighbouring Venezuela, northern Brazil and southeast Colombia with similar habitats but which are very remote and completely unsurveyed.


Population and Trends

There are 21 known collections of this species, at two sites: 17 of the collections were cited in the original Castellano et al. (2012) paper. All are from the same limited geographic area. It may be a common ectomycorrhizal associate of Dicymbe across the wider Guiana Shield region, however this is unknown. The animal vector required for its dispersal is also unknown. It is therefore not possible to estimate how many additional sites it could be found at, and therefore its population size is entirely unknown.

Population Trend: Uncertain


Habitat and Ecology

Elaphomyces digitatus forms ECM with Aldina insignis, and is found in mixed Dicymbe forest.

“Usually in clusters of 2–5 ascomata in hilly country on red lateritic soils at , 710 m in D. corymbosa monodominant forest, also in similar terrain in mixed D. altsonii, D. corymbosa and A. insignis forest, infrequently in sandy, alluvial soil partially embedded in humic material on forest floor under D. corymbosa, rarely elevated 1–2 m up the bole of a D. altsonii in mixed Dicymbe forest, or in D. altsonii-dominated stands at low elevation on brown sand soils; May–July and December–January rainy seasons; known from the type locality in the Upper Potaro River Basin of Guyana and ~100 km east in the Mabura Hill region.” (Castellano et al. 2012)

Subtropical/Tropical Moist Lowland Forest

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. 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. Further impacts of climate change, particularly droughts, are also anticipated.

Mining & quarryingRoads & railroadsUnintentional effects: subsistence/small scale (species being assessed is not the target) [harvest]Habitat shifting & alterationDroughts

Conservation Actions

No conservation actions are currently in place for this species. Protection of habitat is needed.

Resource & habitat protection

Research needed

Additional survey work to document the species’ distribution and abundance, taxonomy, and life history are needed: ascertaining the ectomycorrhizal host plant and the animal vector required for spore dispersal will clarify its ecological requirements.

Population size, distribution & trendsLife history & ecology

Use and Trade

There is no known use of this species.


Bibliography


Known distribution - countries

Regional Population and Trends

Country Trend Redlisted