R-L categories correct, but text here does not match final assessment. Updated version will be published in IUCN´s Red List June or Nov 2019.
Sarcodon leucopus is a conspicous hydnoid species with very large and striking basidiocarps. It is ectomycorrhizal fungus associated with pine on calcareous soil. It has a wide distribution in Europe, but it is very rare everywhere, with a fragmented distribution area. It has become extinct in large parts of Western and Central Europe, due to sensitivity to nitrogen deposition. In Northern Europe it is mainly threatened by cutting of old-growth pine stands. It is listed as Vulnerable under criteria A2c+3c+4c based on a inferred past, ongoing and suspected future decline to exceed 30% in 50 years (three generations).
Sarcodon leucopus is preliminary assessed as Vulnerable based n the criterion A4c based on a suspected, continuing decline of 40% in three generations (50 years).
Anders. Suggest A2c+A3c+A4c
In Europe the species is rather variable and possibly two cryptic species are involved (Maas Geesteranus, 1975). Sarcodon leucopus is reported from Siberia, Japan and North-America, but these records are considered here as doubtful. Conspecifity with European populations has to be proven.
Sarcodon leucopus is distributed in Europe. The records from Japan, Siberia and North-America are not considered to be conspecific
Sarcodon leucopus is rare and occurs on isolated localities throughout its distribution area. A strong decline has been reported from many regions and it is included in many National Red Lists: Extinct in the Netherlands (1849), Belgium (1882), Baden-Württemberg (1977); Critically Endangered in Czech Republic, France, Germany; Endangered in Sweden and Switzerland; Vulnerable in Finland; Near threatened in Norway. The species is unknown from Great-Britain. In Japan two records are known from Hokkaido. Norway is the centre of its global distribution with 120 known localities, mainly in Nordvestlandet, estimated to constitute 25-50% of the global population (Henriksen & Hilmo, 2015). The trend of S. leucopus is negative, with an estimated decrease to exceed 30% (30-50%) during the past 50 years (three generations) According to forest statistics the decline of old pine forests in Scandinavia amounts to approximately 1% on an annual basis. The decline is ongoing and projected to continue at the same rate.
Population Trend: Decreasing
Sarcodon leucopus is an ectomycorrhizal symbiont of old trees of Pinus sylvestris in old, often open coniferous forests on very dry, base-rich to calcareous soils with a very low nutrient status, often on thin soils above bedrock. In Norway S. leucopus is especially found in forests above olevine rocks, a habitat strongly threatened by quarrying.
Sarcodon leucopus is threatened in Western and Central Europe by the nitrogen deposition.The critical nitrogen load for this species is estimated at less than 15 kg N/ha/yr (REF?); a value exceeded now in almost entire Western and Central Europe, where the species has disappeared almost completely. In Northern Europe the species it is mainly threatened by logging of old-growth pine forests, more locally also by quarrying for olivine (Henriksen & Hilmo, 2015; Artdatabanken, 2015).
Reduction of air pollution by limitation of nitrogen emissions by agriculture, traffic and industry. Protection of old pine forests on base-rich mineral soils against clearcut.
Taxonomic research on homogeneity of the species in Europe (some characters are quite variable) and on possible conspecificity with populations from N. America, Japan and Siberia.
Artdatabanken 2015. Rödlistade arter i Sverige, SLU, Uppsala Artdatabanken
Arnolds, E. 2003. De stekelzwammen en Pruikzwammen van Nederland en België. Coolia 46: 1-96.
Maas Geesteranus, R.A.. 1975. Die Terrestrischen Stachelpilze Europas.
HENRIKSEN, S. & HILMO, O. 2015a. Norsk rødliste for arter 2015. Artsdatabanken, Norge.
Nitare, J. 2006. Atgärdsprogram för bevarande av rödlistade fjälltaggsvampar. (Species action plan for red-listed Sarcodon. In Swedish with an English summary). Naturvärdsverket, rapport 5609. Stockholm.
Walleyn, R. & A. Verbeken. 1999. Een gedocumenteerde Rode Lijst van enkele groepen paddestoelen in Vlaanderen.