Hygrocybe swanetica is a rare and easily recognisable colourful waxcup. It grows in an unusual habitat for waxcups, on large logs of Abies. It is only known from Russia (Western Caucasus and Eastern Russia) and Georgia and is restricted to old-growth or virgin forests formed by, or mixed with, Abies. The number of known localities (2018) is 10. Considering unrecorded localities, the total number of localities is estimated not to exceed 30, corresponding to that the number of mature individuals not to exceed 3000. Most findings are located within protected areas. It has not been found in managed forests. Ongoing clearcutting of old Abies forests within its geographic area is a threat and inferred to cause an ongoing decline in the population size. This species qualifies for listing as Vulnerable.
Pseudohygrocybe swanetica (Singer) Kovalenko (Kovalenko, 1989)
Hygrocybe swanetica is a rare mushroom species with colourful and easy recognizable appearance. It was described from Cental Caucasus (Georgia, Swaneti) and then found in several localities in Russian Western Caucasus and Russian Far East. This species is restricted to the old-growth or virgin forests formed by Abies and mixed forests with Abies. Usually it grows on the very large rottten logs and stumps of Abies and on the pieces of wood scattered around. Most of findings have been made inside protected areas, it has never been found in managed forests so it can be considered as an indicator of undisturbed forest communities. At present the large-scaled cutting of old fir forests close to the protected areas creates a threat to species population due to fragmentation of favourable ecotopes.
In Russian Federation Hygrocybe swanetica is protected on a regional level in three administrative units (Krasnodar territory, Adygei and Karachaevo-Cherkesia Republics). It’s recommended to the new edition of the Red Data Book of Russian Federation as Vu B2a; En С2ai. In Georgia it’s not protected. Globally it can be estimated as a threatened species because of a small fragmented population and habitat declining.
Only recorded in Georgia (Cental Caucasus) and Russia: Caucasus (Western and Central); Russian Far East: southern Sakhalin, middle Sikhote-Alin, Zeya river basin, Ussuriysky district. The known distribution is is disjunctive - Georgian and Russian Caucasus and Russian Far East with no records in between.
In total (2018), H. swanetica is is known from 10 localities in Russia and one locality in Georgia (the type locality in Swaneti). It’s registered almost every year in the basin of Belaya river (Russian Western Caucasus, Caucasian State reserve), in others localities the periodicity of fruiting is not known. One of known localities (outside protected areas) is most probably destroyed due to clearcutting.The total number of localities (incl. unknown) is estimated to be 50 and not to exceed 300. Typically, it is recorded from one log per site. Number of mature individuals (two mature individuals per functional individual, i.e. per trunk or log, c.f. Dahlberg & Mueller, 2011) is estimated to not to exceed 3000 (if conservatively assuming maximum 5 logs colonised with H. swanetica per locality). Habitat decline is ongoing due to clearcutting of old-growth forests of Abies and decreasing the amount of large logs, as well as disturbance of suitable habitats by road construction.
Population Trend: Deteriorating
Hygrocybe swanetica is one of few Hygrocybe species growing in rotten dead wood. It grows on large logs, up to 2 m in diameter, stumps, and pieces of scattered wood of Abies, sometimes also in soil containing wooden remains. It was found on Abies nordmanniana in Caucasus and A. holophylla in Far East. It appear to be rare at all known sites, typically with one records/site. Most of collections have been made in old-growth or virgin mesophilous forest formed by Abies and mixed forests with Abies. In Caucasus it was found only in forests with tertiary relict plant species (Rhododendron ponticum, Helix colchica etc.) (Red Data Book. 2012, 2017). Most known localities are located inside protected areas with different status of protection. It has not been been recorded in young or managed forests.
The main threat is declining of old-growth forests (clearcutting) and decreasing of large logs, as well as disturbance of suitable habitats by road construction and other human activities. For examples, some sites of valuable old forests were cut down during preparation to the Olympic Games in Sochi.
It’s protected on the regional level in in Russia at three administrative units (Krasnodar territory, Adygei and Karachay-Cherkess Republic), and preserved in three state nature reserves. It’s recommended to the new edition of the Red Data Book of Russian Federation as Vu B2a; En С2ai. In Georgia it’s not protected. All known sites should be protected. Needs continued protection of all habitats, old-growth Abies forests.
Research on the specie´s life history and ecology and better knowledge its geographic distribution.
The species is not used.
Singer R. 1931. Pilze aus dem Kaukasus. II. Ein Beitrag zur Flora Swanetiens und einiger angrenzender Ta’ler // Beih. Botanischen Centralblatt. 48: 513-542.
Kovalenko A.E. Definitorium Fungorum URSS. Ordo Hygrophorales - Leningrad: “Nauka”, 1989. 175 p. [in Russian]
Plantae non vasculares, fungi et bryopsida orientis extremi rossica. Fungi. T. 3 : Ustomycetes (Ustilaginales), Basidiomycetes (Hygrophorales), Ascomycetes (Laboulbeniales - Laboulbeniaceae et Peyritschiellaceae), Zygomycetes (Entomophthorales - Entomophthoraceae), Chytridiomycetes (Blastocladiales - Coelomycetaceae) / Z.M. Azbukina, O.K. Govorova, I.V. Karatygin, A.E. Kovalenko, E.Z. Koval - SPb: “Nauka”, 1995. 383 p. [in Russian]
Red Data Book of Karachaevo-Cherkesia Republiс. Cherkessk, Nartisdat,2013. 316 p (In Russian)
Red Data Book of Krasnodar Kray: Plants and fungi. III edition. / Edited by S.A.Litvinskaya - Krasnodar: Adm. of Krasnodar Kray, 2017. - 850 p. (In Russian)
Red Data Book of Republic of Adygeya. Rare and threatened representatives of the regional fauna and flora. Part 1. Introduction. Vegetabilia and Mycota. - The second edition. Maykop: Kachestvo, 2012. 340 p. (In Russian)
Flora, vegetation and mycobiota of the reserve “Ussuriysky”/ Z.M. Azbukina et al. - Vladivostok: Dalnauka, 2006. 300 p.(In Russian)
Plants, fungi and lichens of the Sikhote-Alin Reserve / the team of authors/ ed. E.A. Pimenova - Vladivostok: Dalnauka, 2016. - 557 p.