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Hydnellum mirabile (Fr.) P. Karst.

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Scientific name
Hydnellum mirabile
Author
(Fr.) P. Karst.
Common names
raggtaggsvamp
børstebrunpigg
lošákovec podivný
IUCN Specialist Group
Mushroom, Bracket and Puffball
Kingdom
Fungi
Phylum
Basidiomycota
Class
Agaricomycetes
Order
Thelephorales
Family
Bankeraceae
Assessment status
Published
Assessment date
2015-04-27
IUCN Red List Category
VU
IUCN Red List Criteria
A2c+3c+4c
Assessors
Nitare, J.
Reviewers
Dahlberg, A.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/70408415/70408439

Justification

The hydnoid fungus Hydnellum mirabile is a rare, conspicuous and well-investigated species that has decreased in many parts of Europe, and has disappeared from some regions and has its main distribution concentrated to Fennnoscandia. It forms mycorrhiza with coniferous trees, mainly Norway Spruce (Picea abies), occasionally Scots Pine (Pinus sylvestris) in old-growth, herb-rich coniferous forests on base-rich or calcareous soils (Nitare 2006). The species seems to have a narrow ecological niche and special requirements. H. mirabile can be considered an indicator species of remnants of old spruce forest ecosystem on productive soils with long continuity, not affected by large-scale disturbances. These productive forest habitats are of high economic value and under heavy pressure from forestry. The prime cause for the decline of H. mirabile is clear-cutting. This old-growth habitat of H. mirabile  is estimated  to have decreased by more than 30% during the past 50 years  in Fennoscandia where it has its main distribution (estimated three generations) and probably more than 50% in a perspective of 100 years (Nitare 2006, Dahlberg and Mueller 2011). The decline of sites with H. mirabile is assessed to be in  the same magnitude. Therefore it is classified as Vulnerable under criteria A2c+3c+4c.

Taxonomic notes

Hydnellum mirabile is a well-characterized hydnoid fungus with large basidiocarps with an up to 15 cm broad, pale yellow to olive-brown, hispid pileus and a pale context with a weak adstringent taste. It has a mycorrhizal association  with coniferous trees (Maas Geesteranus 1975). However, the species has sometimes been confused with H. compactum (Pers.) P.Karst. That species differs i.a. in the pileus surface without hispid hairs, the strongly acrid taste and its association with deciduous trees (Maas Geesteranus 1975). In the past the two related species were known under the confusing name H. acre (Maas Geesteranus 1975). Hydnellum  mirabile  has been reported from North America, but all material should be compared to Eurasian material before it may be regarded as conspecific (Harrison 1961, Baird et al. 2013).

This assessment excludes the North American records.

Geographic range

In Europe Hydnellum  mirabile has a bicentric distribution within the natural range of Norway Spruce (Picea abies). The main area of occurrence is situated in the hemiboreal zone (Norway, Sweden, southern Finland into Russia) (Nikolajeva 1961; Gulden and Hanssen 1992a, b). It is also occurs  in the mountains of Central Europe (The Alps and Carpathians). It is unknown form northwest Europe, including Denmark, Germany, United Kingdom, the Netherlands and Belgium.

Population and Trends

Hydnellum mirabile is known from approximately 200 localities in Fennoscandia and maybe 20-25 localities in central  Europe. The number of localities in Russia is unknown. The total number of localities (including undiscovered ones) is estimated at less than 500, usually with small populations of 1-10 individuals each (less than 5,000 mature individuals in total).

The population of H. mirabile is decreasing throughout its range, mainly due to the impacts of forestry. Appropriate old-growth forests are estimated to have decreased with between 30-50% during the past 50 years  (estimated three generations)  (Nitare 2006, Dahlberg and Mueller 2011).  The decline of sites with H. mirabile is estimated to be in the same  magnitude.

Population Trend: decreasing


Habitat and Ecology

Hydnellum mirabile forms ectomycorrhiza with coniferous trees, mainly Norway Spruce (Picea abies), occasionally Scots Pine (Pinus sylvestris). It is confined to  old-growth, moss- and herb-rich coniferous forests on base-rich (calcareous) soils. The species is favored by long continuity of spruce (ancient boreal spruce forests) and seems to have very special requirements, growing in a narrow ecological niche in its entire range. H. mirabile is an indicator-species of hotspots of species diversity. Sites with this species are always very rich in rare and threatened species of fungi.

Threats

The main threat to Hydnellum mirabile  is destruction of its habitat by logging. The species disappears after clear-cut felling, and seems not to be able to reappear in younger forest stands.  At present there is heavy pressure on exploitation of remnants of old-growth spruce-dominated forests on productive soil (see Population Trend).  The decline of the habitat is expected to continue in future. An additional threat to H. mirabile, in particular in central Europe, is the accumulating effect of air pollution, in particular nitrogen deposition (Gulden and Hanssen 1991). The species is Red-listed in five European countries: Czech Republic (regionally extinct), France (Endangered), Finland (Vulnerable), Norway (Vulnerable) and Sweden (Endangered).

Conservation Actions

Sites of  Hydnellum mirabile are rarely protected in nature reserves. Protection of appropriate old-growth forest  habitat is needed as it does not survive clear-cutting forestry.


Use and Trade

The species is not known to be used

Source and Citation

Nitare, J. 2015. Hydnellum mirabile. The IUCN Red List of Threatened Species 2015: e.T70408415A70408439. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T70408415A70408439.en .Accessed on 3 February 2024

Country occurrence