This is a bright eye-catching wood-inhabiting saprotrophic fungus with Holarctic distribution, inhabiting mainly boreal and mountain forest communities. It is declining on a European scale due to decreasing area of virgin or old growth spruce and fir forests and a poor capability to spread and establish in forests after clearcutting. The total number of localities has decreased by at least 20% for 50 years. It is regarded threatened in five European countries and 5 regions of Russia. The population in the North America is numerous and seems stable. Assessment is based on observed population reduction in Europe as Vulnerable under criteria A2c+3c+4c on the European level, but LC globally.

Pycnoporellus alboluteus (Ellis & Everh.) Kotl. & Pouzar, Česká Mykol. 17(4): 174 (1963)
Synonymy:
Aurantiporellus alboluteus (Ellis & Everh.) Murrill,
Aurantiporus alboluteus (Ellis & Everh.) Murrill,
Fomes alboluteus Ellis & Everh.,
Hapalopilus alboluteus (Ellis & Everh.),
Phaeolus alboluteus (Ellis & Everh.) Pilát,
Polyporus alboluteus (Ellis & Everh.) Ellis & Everh.,
Scindalma alboluteum (Ellis & Everh.) Kuntze,

This is a Holarctic circumboreal species known in the boreal and mountainous parts of Europe, the Caucasus, Asia, and North America.
The main part of the global population seems located in North America, especially in the western part: it is known from all the western USA states (e.g., Washington, Oregon, and the mountains of California), with recent reports also from eastern USA and Florida. In Europe, the population is much smaller and fragmented, with most of the records originating in the Scandinavian Peninsula (Sweden, Finland and Norway) and rather few locations in 11 other countries (e.g., eight locations in Estonia, five in Latvia, one in Belarus, Poland, Germany, Slovakia, Spain, and Serbia).
In Russia, it is known in 13 regions within the European part (Lenigradskaya, Arkhangelskaya, Moskovskaya, Tverskaya Oblasts, Krasnodar Kray, Republics Karelia and Karachaevo-Cherkesia),  Ural (Perm Kray, Sverdlovskaya Oblast, Republic Komi), Siberia (Tomskaya and Tumenskaya Oblasts) and Far East (Kamchatka).

The species occurs almost exclusively in boreal and mountain old-growth forests of spruce (Picea abies, P. obovata, P. glauca, P. engelmannii, P. pungens) and fir (Abies alba, A.  concolor, A. nordmanniana, A. lasiocarpa) with the majority of the European localities known from the Scandinavian Peninsula and Russia. It favours moist conditions of well preserved old forests of natural character, with abundance of huge overmossed fallen logs in various stages of decaying, therefore, it is absent in wide range of managed forests. The species seems to have poor ability to spread and establish in forests after clearcutting.

In total, less than 1500 records of this species are known; nearly 60% from North America, 40% from Europe, and single locations in Asia.
among them from America and Europe (~ 750 - USA+Canada; 120 - Europe, 2- George),  however the most of them were made more then 50 years ago,  besides the number of known localities in Europe decreased by at least 20 percents for 50 years. Today (1969-2019) it’s registered ~ 22 in Europe (incl. Caucasus). In several European countries P.alboluteus is considered as very rare and declining species and included in Redlists of Norway (Cr), Finland (En), Sweden (Cr), Estonia (Cr).
There are about 50 records related to ~ 30 localities (for the all time) in Russia, mostly known from recent time due to active investigations during the last two decades. Current trends in Russia could be considered as decreasing due to intensive timber harvesting (especially in Asian part) and partly habitat degradation.
Evaluation period 50 years = 3 generations (according to the recommendation of Dahlberg & Mueller, 2011). In North America the population is bigger and quite stable. Preliminary this species could be assessed as Vu A2c +3c +4c at European level but LC at Global level.

The species is an annual xylosaprotroph producing soft and spongy pollyporoid sporophores, which grows mainly on coniferous wood, causing brown rot. It is reported to colonise Picea abies, P. obovata, P. glauca, P. engelmannii, P. pungens, Abies alba, A. concolor, A. nordmanniana, A. lasiocarpa, Larix sp., Pinus sp., Pseudotsuga sp., Tsuga sp., and very rarely deciduous trees, viz. Populus tremuloides, P. trichocarpa, and Alnus sp.
The sporophores appear, as a rule, on the underside surfaces of logs in their central part, not in contact with the ground, at an early stage of decomposition, between the wood and the detaching bark, or shortly after the bark has fallen off. On the logs closely attached to the ground, the fruitbodies form on the lateral or even the upper sides, consisting of roof-like nodules. Most often, they emerge from fissures or clefts in the trunk, or from under the bark at the edge of decorticated wood. At least in Europe, they are repeatedly reported to grow on the substrate already colonised by Fomitopsis pinicola (Sw.) P. Karst.
The usual habitats of this fungus are situated in relief depressions which are well-drained throughout the growing season, housing temporary rivers during the spring, and a thick, long-lasting snow cover in the winter. The surrounding vegetation is luxuriant and relatively humid, like mixed deciduous forests with spruce or spruce and fir forests with aspen and other deciduous species, with gaps enriched with fallen logs of various decay stages.
Pycnoporellus alboluteus is considered as indicator species of well preserved forests of natural character (Niemelä 2013).
The American authors repeatedly report that the species grows near the receding snowline, or during the winter and spring on snow-covered trees. In Europe, it is found mainly at the beginning of autumn.

Forests clearcutting, habitat degradation because of removing of old trees and fallen logs, intensive recreational activities

Setting aside spruce and fir forest reserves where the species have good populations. At these forests, natural or prescribed burning should be considered to maintain desired forest dynamics. The removing of fallen logs in served areas should be prohibited.

Dahlberg A & Croneborg H. 2003. 33 threatened fungi in Europe. Complementary and revised information on candidates for listing in Appendix I of the Bern Convention T-PVS (2001) 34 rev 2.
Hintikka V. 1970. First record of Pycnoporellus alboluteus in NW Europe. Karstenia 11: 33-34.
Niemelä T. 1980. On Fennoscandian polypores 7. The genus Pycnoporellus. Karstenia 20: 1-15.
Tortić M., Jelić M. 1974. New European records of Tyromyces kmetii and Pycnoporellus alboluteus (Polyporaceae) and the identity of Irpex
woronowii Bres. Česká Mykologie 28: 26-34.

Khermansson Ya.  Representatives of Polyporaceae s.l. and some other genera of Aphyllophorales in Pechoro-Ilychsky Reserve// Flora and vegetation of Pechoro-Ilychsky Reserve. Ekaterinburg: 1997. C. 326-365.(In Russian)
Kosolapov D.A. Aphyllophoroid fungi of middle-taiga of European north-west Russia. Ekaterinburg, 2008. C. 56. (In Russian)
Mukhin V.A., Kotiranta Kh., Uchakova N.V. Polypores of Beringia sector of Holarctica // Fundamental and applied problems of botany at the beginning of XXI century: Proceedings of the All-Russian Conference (Petrozavodsk, September 22-27, 2008). Part 2: Algologia. Mycology. Lichenology. Bryology. Petrozavodsk: Karelian Research Centre, 2008.P. 135-137.(In Russian)
Parmasto E.Kh. To mycological flora of Komi ASSR// Proceeding on botany: scientific notes of Tartu University, 1963. V.136. C. 103-129 (In Russian)
Red Data Book of Karachaevo-Cherkesia Republik. Cherkessk, Nartisdat,2013. 316 p (In Russian)
Ruokolainen A., Manninen O. 2014. Aphyllophoroid fungi of Zaonezhye Peninsula. Biogeography, landscapes, ecosystems and species of Zaonezhye Peninsula, in Lake Onega, Russian Karelia. Reports of the Finnish Environment Institute. Vol. 40. Helsinki. P. 221-244.
Stavishenko I.V. Rare species of xylotrophic fungi of Vishersky Reserve // Modern Mycology in Russia: Abstracts of 1 congress of mycologists of Russia. Moscow, 2002. C.98-99. (In Russian)
Stavishenko I.V. [Ставишенко И.В.] 2006. Xylotrophyc fungi in the Visim Nature Reserve. Ecological researches in the Visim biosphere Nat. Res.: Proc. conf. of Visim Nat. Res. 35 years / Yu.F. Marin (ed.). Ekaterinburg: Middle Ural publ. P. 294-303. (In Russian)
Niemelä T., Kinnunen J., Lindgren M., Manninen O., Miettinen O., Penttilä R., Turunen O. (2001) Novelties and records of poroid Basidiomycetes in Finland and adjacent Russia // Karstenia 41(1):1–21
Novoselov A. P. (ed) (2008) Red Data Book of the Arkhangelsk Region [Красная книга Архангельской области]. Arkhangelsk: Committee for Ecology of the Arkhangelsk Oblast. 351 p. (in Russian)
Ezhov O. N. (2013) Aphyllophoroid fungi of the Arkhangelsk Oblast [Ежов О. Н. Афиллофоровые грибы Архангельской области]. Yekaterinburg: RIO UrO RAN. 276 p. (in Russian)
Ezhov O. N. (2014a) Complexes of spruce-associated aphyllophoroid fungi in the North of the Russian Plain (Arkhangelsk Region and adjacent areas) [Ежов О. Н. Комплексы афиллофороидных грибов, ассоциированные с елью европейской на севере Русской равнины (Архангельская область и сопредельные регионы)] // Transactions of Karelian Research Centre of the Russian Academy of Sciences (2):77–85 (in Russian)
Ezhov O. N., Ershov R. V., Ruokolainen A. V., Zmitrovich I. V. (2011) Aphyllophoroid fungi of the Pinezhsky Nature Reserve [Ежов О. Н., Ершов Р. В., Руоколайнен А. В., Змитрович И. В. Афиллофоровые грибы заповедника «Пинежский»]. Yekaterinburg: UrO RAN. 148 p. (in Russian)
Ezhov O. N., Zmitrovich I. V. (2015) Checklist of aphyllophoroid fungi (Agaricomycetes, Basidiomycota) in boreal forests of Pinega Reserve, north-east European Russia // Check List 11(1):1–11
Kotkova V. M. (2014b) Aphyllophoraceous fungi (Basidiomycota) in forest ecosystems of Setra River Basin (Arkhangelsk Region) [Коткова В. М. Афиллофоровые грибы (Basidiomycota) в лесных экосистемах бассейна реки Сётра (Архангельская область)] // Novosti sistematiki nizhshikh rasteniy 48:130–145 (in Russian)
Ruokolainen A., Manninen O. (2014) Aphyllophoroid fungi of Zaonezhye Peninsula // Reports of the Finnish Environment Institute 40:233–256
Parmasto E. (1963) Data on the fungus flora of the Komi A.S.S.R. [Пармасто Э. К микологической флоре Коми АССР] // Tartu Riikliku Ülikooli toimetised. Vihik 136. Botaanika-alased tööd. 6. Tartu. P. 103–129 (in Russian)
Parmasto E., Parmasto I. (1979) The xanthochroic reaction in the Aphyllophorales // Mycotaxon 8(1):201–232
Hermansson J. (1997) Members of the family Polyporaceae s. lat. and some other genera of the order Aphyllophorales in the Pechora-Ilychsky Reserve [Хермансон Я. Представители семейства Polyporaceae s. lat. и некоторых других родов порядка Aphyllophorales в Печоро-Илычском заповеднике] // Degteva S. V. (ed) Flora and plant cover of the Pechoro-Ilych Biosphere Preserve. Yekaterinburg: Ural Branch of RAS. P. 326–368 (in Russian)
Bondartseva M. A. (1998) Definitorium fungorum Rossiae. Ordo Aphyllophorales. Fasc. 2. Familiae Albatrellaceae, Aporpiaceae, Boletopsidaceae, Bondarzewiaceae, Corticiaceae (genera tubuliferae), Fistulinaceae, Ganodermataceae, Lachnocladiaceae (genus tubuliferus), Phaeolaceae, Polyporaceae (genera tubuliferae), Poriaceae, Rigidoporaceae. Saint Petersburg: Nauka. 391 p. (in Russian)
Ushakova N. V. (2000) Fungi-indicators of the native dark coniferous forests of the Urals [Ушакова Н. В. Грибы-индикаторы коренных темнохвойных лесов Урала] // Ekologiya protsessov biologicheskogo razlozheniya drevesiny. Yekaterinburg. P. 6–15 (in Russian)
Kosolapov D. A. (2008b) Aphyllophoroid fungi of middle taiga forests of European North East of Russia [Косолапов Д. А. Афиллофороидные грибы среднетаежных лесов европейского Северо-Востока России]. Yekaterinburg: UrO RAN. 230 p. (in Russian)
Taskaev A. I. (ed) (2009) Red Data Book of the Komi Republic [Красная книга Республики Коми]. Syktyvkar: Institute of Biology of the Komi Science Centre of the Ural Division RAS. 791 p. (in Russian)
Ezhov O. N. (2014a) Complexes of spruce-associated aphyllophoroid fungi in the North of the Russian Plain (Arkhangelsk Region and adjacent areas) [Ежов О. Н. Комплексы афиллофороидных грибов, ассоциированные с елью европейской на севере Русской равнины (Архангельская область и сопредельные регионы)] // Transactions of Karelian Research Centre of the Russian Academy of Sciences (2):77–85 (in Russian)
Zmitrovich I. V. (2003) Tremelloid, aphyllophoroid and pleurotoid Basidiomycetes of Veps Plateau (Northwest Russia) // Karstenia 43(1):13–36
Popov E. S., Morozova O. V., Kotkova V. M., Novozhilov Y. K., Zhurbenko M. P., Zmitrovich I. V., Kovalenko A. E. (2007) Preliminary list of Fungi and Myxomycetes of Leningrad region. Saint Petersburg: TREEART LLC. 56 p.
Ushakova N. V. (2000) Fungi-indicators of the native dark coniferous forests of the Urals [Ушакова Н. В. Грибы-индикаторы коренных темнохвойных лесов Урала] // Ekologiya protsessov biologicheskogo razlozheniya drevesiny. Yekaterinburg. P. 6–15 (in Russian)
Kotiranta H., Ushakova N., Mukhin V. A. (2007) Polypore (Aphyllophorales, Basidiomycetes) studies in Russia. 2. Central Ural // Annales Botanici Fennici 44(2):103–127
Kotkova V. M. (2012) Study aphyllophoroid fungi in the forests of the Tsentralno-Lesnoy State Nature Biosphere Reserve [Коткова В. М. Изучение афиллофоровых грибов в лесах Центрально-Лесного государственного природного биосферного заповедника] // Zheltukhin A. S. (ed) Dinamika mnogoletnikh protsessov v ekosistemakh Tsentralno-Lesnogo zapovednika. Trudy Tsentralno-Lesnogo gosudarstvennogo prirodnogo biosfernogo zapovednika. Vypusk 6. Velikiye Luki. P. 307–318 (in Russian)
Kotkova V. M. (2014) Fungi of the Tsentralno-Lesnoy Nature Reserve (annotated list of species) [Коткова В. М. Грибы Центрально-Лесного заповедника (аннотированный список видов)]. Flora and fauna of nature reserves. Vol. 122. Moscow. 94 p. (in Russian)
Kotkova V. M., Niemelä T., Viner I. A., Schigel D. S., Kurakov A. V. (2015) Polypore fungi: materials of the international course on ecology and taxonomy of lignicolous basidiomycetes in the Central Forest Reserve [Коткова В. М., Ниемеля Т., Винер И. А., Щигель Д. С., Кураков А. В. Трутовые грибы: материалы международного кура по экологии и таксономии дереворазрушающих базидиомицетов в Центрально-Лесном заповеднике]. Helsinki: Helsinki University Printing House. 95 p. (in Russian)
Viner I. A., Schigel D. S., Kotiranta H. (2016) New occurrences of aphyllophoroid fungi (Agaricomycetes, Basidiomycota) in the Central Forest State Biosphere Nature Reserve, Tver Region, Russia // Folia Cryptogamica Estonica 53:81–91
GBIF https://www.gbif.org/occurrence/search?offset=0&q=Pycnoporellus alboluteus