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.
Bondarcevomyces taxi is a very rare wood-inhabiting polypore growing on dead wood of Taxus baccata and Chamaecyparis formosensis (EN) in old-growth forests and characterized by clearly disjunctive areal forming by a few small mountain areas in Caucasus, South Siberia, Russian Far East, China, Taiwan and Japan. It has a well noticeable dark-orange strongly smelling fruit body which hardly can be overlooked. In spite of conspicuous appearance and special searching at the moment only 11 finds were recorded in 8 localities.
Preliminary redlist assessment: The total population is estimated <100 localities. The number of mature individuals per site is likely 2-5, so in total is 200-500. It can be assessed preliminary as Vulnerable C2a (i) because of a few known localities in the world (it’s assumed < 1000 mature individuals) and declining of habitats with Taxus baccata (in Russia) and Chamaecyparis formosensis.
Basionym: Polyporus taxi Bondartsev, Bot. Materialy Otdela Sporovykh Rastenii,V (1-3): 17 (1940);
Syn.: Hapalopilus taxi (Bondartsev) Bondartsev et Singer, Ann. Mycol. 39: 52 (1941);
Parmastomyces taxi (Bondartsev) Dai et Niemelä, Ann. Bot. Fennici 32: 222 (1995);
Tyromyces taxi (Bondartsev) Ryvarden et Gilb., Europ. Polypores, Pt. 2: 693 (1994)
According to phylogenetic analysis this species represents a separate brench in Boletales clade (Larsson et al., 2004), Binder, Hibbert, 2006; Binder et al., 2010)
Bondarcevomyces taxi is a transeurasian temperate polypore known predominantly in mountain regions of Caucasus, Siberia, Russian Far East, China, Japan, and Taiwan.
It was found in 5 regions of Russia: Western Caucasus (Krasnodar Kray, Adygeya Republic), Southern Siberia (Salair) and Far East (Khabarovsk Kray and Primorsky Kray). In Russia 8 finds are known today. In China it was found in Jilin Prov. (Changbai Co., Changbai Forest Reserve), in Taiwan it’s known from Ilan Prov., in Japan - Yuho, Toyama, Toyama Pref. (Hosoya, 2018). In Caucasus this species was found in relict plant communities with Taxus baccata. The type locality (yew-box groove in Khosta river canyon) is under threat of destroying because of epiphytoty of Buxus colchica and recreation press (http://maks-portal.ru/obshchestvo/video/chrezvychaynaya-situaciya-obyavlena-v-tiso-samshitovoy-roshche-ona-mertva-na-70) . Another locality is situated in unprotected area of Adygea Rep., it is vulnerable too. Plant communities with Taxus baccata are declining in Caucasus and this process is expected to continue in the next 50 years, followed by the decline of the species. Besides Chamaecyparis formoensis, another host of B.taxi in China now is also under threat of habitat loss, and it’s estimated as EN (https://en.wikipedia.org/wiki/Chamaecyparis_formosensis). The rest specimens was found in reserves (excl. Salair (Siberia) and Taiwan?) on Larix gmelinii, Larix sp. and Pinus koraiensis.
It is very important to note that in spite of wide distribution of Taxus baccata in Europe up to now only 11 records of B.taxi are known. This species is quite big and bright, has a strong smell, so it’s hardly possible to overlook it. Nevertheless there are no any records from the well mycologically studied Europe where Taxus baccata is widespread. Thus, the presence of a substrate in this case is not the only condition for the existence of this species, so obviously Bondarcevomyces taxi has some specific and narrow ecological preferences leading to global rareness.
Population Trend: Decreasing
It is a highly specialized wood-inhabiting fungus that causes brown heart rot (Parmasto, 1999) mostly of Taxus baccata and Chamaecyparis formoensis. B. taxi was registered for the first time on a stump of Taxus baccata in the Black Sea region of Caucasus. Then it was found on Chamaecyparis formosensis as well as single finds on Larix gmelinii (= L. dahurica) and Pinus koraiensis in Siberia and Far East. There is not enough data on its ecology. Presumably it is a saprotrophus but perhaps colonizes living trees and continues to degrade wood after the tree death. Specific set of colonized trees may be an evidence of the high specialization to woody substrate. The known collections have been found mainly in
protected areas of old-growth forests, so it can be supposed that this species tends to old forests. Usually only fruitbody has been found per tree and site what lets us estimate 1 functional individual and 2-5 mature individual per locality.
The main threat for the Caucasian subpopulation is the rapid declining of wild Taxus due to weak competitive ability in the changing enviroment, as well as intensive development of human activity (recreation, building, cutting down of Taxus tree for souvenirs, etc.). Also at the moment there is a strong threat of destroying Caucasian localities because of epiphytoty of Buxus colchica which forms plant communities together with Taxus baccata. Another host of B. taxi Chamaecyparis formoensis now is also under threat of habitat loss (see population trends above).
All known localities of B.taxi must be protected.
Detailed information about biology, ecology and distribution of this very rare species is needed. Data on genetics of individual and population size in different parts of the world would be very useful.
There is no any data on practical use of this species
Bondartsev A. S. Polypores of European part of Russia and Caucasus. - Moscow, Acad. Press, 1953. - 1106 p. (In Russian)
Vassilieva L. N. Fungi of Caucasian Reserve. - Uchenye Zapiski Kazanskogo universiteta. Otdelnyi ottisk. - Kazan,1939. - Vol. 99 (1). - 66 p. (In Russian)
Parmasto E. Bondarcevomyces, a new genus of polypores (Hymenomycetes, Basidiomycota) // Mycotaxon. – 1999. – Vol. 70. – P. 219-225.
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.
Zhang, D & Christian, T. 2013. Chamaecyparis formosensis. The IUCN Red List of Threatened Species 2013: e. Downloaded on 28 February 2018.
Hosoya T (2018). Fungal Specimens of National Museum of Nature and Science (TNS). National Museum of Nature and Science, Japan. Occurrence dataset https://doi.org/10.15468/y8xhm7 accessed via GBIF.org on 2019-03-16. https://www.gbif.org/occurrence/1946415279
Larsson,K.H., Larsson,E. and Koljalg,U. High phylogenetic diversity among corticioid homobasidiomycetes // Mycol. Res. 108 (PT 9), 983-1002 (2004)
Binder,M. and Hibbett,D.S. Molecular systematics and biological diversification of Boletales // Mycologia 98 (6), 971-981 (2006)
Binder,M., Larsson,K.H., Matheny,P.B. and Hibbett,D.S. Amylocorticiales ord. nov. and Jaapiales ord. nov.: early diverging clades of agaricomycetidae dominated by corticioid forms //Mycologia 102 (4), 865-880 (2010)
Bondarcevomyces taxi (Bondartsev) Parmasto, comb. nov. http://www.westerdijkinstitute.nl/Collections/BioloMICS.aspx?TableKey=14682616000000063&Rec=4633&Fields=All
GBIF https://www.gbif.org/occurrence/search?q=bondarcevomyces taxi