R-L categories correct, but text here does not match final assessment. Developed and updated version published at IUCN´s Red List update, July 18th 2019.
The orange polypore is a well known, conspicuous and much searched for rare wood-inhabiting polypore restricted to veteran trees of Quercus and Castanea in forest, farmland, parks and pastures. Its is a globally widely spread and present in North-east America, Europe and Easter Asia. It appear to have its main population in Europe. It is very rare in North-east America. It has a wide distribution and the status in Asia is unclear but assessed as more favourable than in Europe.
The population of the orange polypore has significantly declined during the last 200 years in in Europe and North America as the amount of coarse oaks and chestnuts have strongly declined and become very rare and scattered. The reasons are cutting and agriculture development and in the US also that the Amwrican chestnuts (Castanea dentata) was wiped out in the early 1900s by the devasting effects of chestnut blight (Cryphonectria parasitica). The future of the orange polypore in Europe looks bleak as the age-structure of oaks in Europe show serious gaps in the age structure, a few old coarse veteran oaks (>400 yrs), few mature oaks (200-400 years) and many young oaks (< than 100yrs ).
The orange polypore typically grow on trees several hundred years old.It has long lived individual mycelia that may persist for several hundreds of years. The evaluation period is estimated to be 100 years (=3 generations which in this long-lived species is considered to be more than 33 years).
Preliminary global red-list assessment: DD (Data Deficient) due to unknown status in Asia and North America. Can hopefully soon be cleared and a more comprehensive global assessment made.Red-List evaluation for Europe turns out to be CR (Critically Endangered).
A globally (and in Europe) widely spread species and not qualifying for criteria B and D. Difficult to estimate the population size, although in Europe it is known from about 100 localities (the highest no in Sweden, Latvia and Germany), with typically single to few occurrences (mycelia) per site. Possibly could the C-criteria be used. However, in the lack of estimation of population size, only criteria A can be used and population development inferred from habitat development. The evaluation period is estimated to be 100 years (=3 generations which in this long lived species is considered to be more than 33 years).
Should be namned Aurantiporus croeus (ref)
Hapalopilus croceus is distributed the temperate parts of eastern parts of North America, Europe and the eastern parts of Asia (China and Japan).
It has its main distribution in Europe where its is widely spread but rare, following the distribution of oak (Quercus) from the Mediterranean Sea to the northern boundary of oak in northern Europe. It is present but rare in eastern USA and also has been reported from eastern Canada. It is widely distributed but not common in south-western to north-eastern China (the regions Sichuan, Hubei, Guangdon, Jilin and Heilongjiangin). It is not rare in Japan, distributed on deciduous coarse and old oaks in Japan, especially in northern Japan.
Hapalopilus croceus is known from 24 European countries, but everywhere scattered and rare, The largest populations occur in in Sweden and Latvia, each with about 1/3 of Europe’s known sites. (( In France 5 localities, 2 before 1920 (PAM). One tree in Denmark.))
Because oak trees has been intensively utilized for several hundreds of years in Europe, the orange polypore is in a long-term decline and s rare throughout Europe and limited to sites with veteran oaks. Oak forests in most of European countries have been severely exploited through the centuries, in particular since 1800. Old and coarse oak trees are therefore rare or absent over large areas, and when present limited to few individual trees.Today the felling of such trees has largely ceased. However, most places lacking an intermediate generation of oaks, which creates a discontinuity and thus an ecological “bottleneck”. Decline of veteran oaks has happened in both forests and in the agricultural landscape including parks and cemeteries.
The present population of H.croceus in North America is rare but widely distributed in eastern North America. Hapalopilus croceus is considered to have largely declined due cutting and conversion of forests to farmlands. In the beginning of 1900, the introduction of chestnut blight (Cryphonectria parasitica) wiping out the American chestnut (Castanea dentata) wiping out causing an almost a and cutting forestry exploitation cultivation ktivation since the early settlers significantly due to the early settlers significantly rare considered to have
Hapalopilus croceus is nationally red-listed in 11 European countries. It is considered to have its main present distribution in Sweden (listed CR), Poland (listed EN), Russia (not evaluated), Germany (CR) Estonia (CR) and Latvia (EN).
Preliminary global red-list assessment: DD (Data Deficient) due to uncertatin status and trend in Asia and North America. Red-List evaluation for Europe turns out to be CR (Critically Endangered).
Population Trend: Decreasing
The orange polypore is a magnificent saffron-orange-red, fleshy wood-inhabiting fungus that grows on old and coarse veteran trees, mainly oak (Querqus) but also Chestnut (Castanea) in forests, farmland, parks and pastures. It is a saprotroph and seems also to be a weak parasite on old and coarse oversized, living and dead oak trees (veteran trees), both standing and lying down. In Europe, most observations are is done on living, old, giant and hollow oaks, where the fruitbodies appear on dead parts of the tree, most of the lower part of the trunk, the tree’s base and in the cavity. It may also to produce fruitbodies on fallen trunks for decades (Sunhede 1997). Fruiting mycelia have been found in dead oak stumps (Sunhede & Vasiliauskas 2003). Hapalopilus croceus probably colonize living trees exposed wood on the tree due to damages, growing in the dead heartwood, and continuing degradation after the tree has died and fell over. Each oak holds probably only one mycelium, genetic individual. Fruit bodies are annual, but the mycelial individuals can be very long lived, many decades and potentially until the wood is rotted out, which of oak may take several hundred years. At the only locality in Denmark, what is considered to be the same individual mycelia (genotype) has been fruiting for more than 70 years.
The species is threatened by a) its infrequency due to lack of old oaks, b) a severe shortage of intermediate aged oaks to replace the old veteran oaks colonized by H. croceus, c) old oaks that are dying prematurely due to shading from surrounding trees and d) maintenance of parks, pastures and nature reserves sometimes results in damaged or dead oaks or parts of oaks being removed, which is also unfavorable at the sites where the species occurs.
Old oaks colonized by H. croceus and other potential veteran oak trees must be protected. Entire stands of uneven-aged oak must be preserved in landscapes where H. croceus occurs.
A better knowledge of the species ecology, in particular its population biology; at what conditions does it establish, its potential to successfully disperse and colonize at low population densities. Research should also be conducted to investigate the potential to establish H . croceus by mycelial inocculation into oaks.
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.
Artsdatabanken 2010. Safrankjukem,Hapalopilus croceus (Fact sheet in Norwegian). Artsdatabankens faktaark ISSN1504-9140 nr. 137, Tronheim, Norway. http://www2.artsdatabanken.no/faktaark/Faktaark137.pdf
ArtDatabanken 2012. Hapalopilus croceus, saffransticka (Fact sheet in Swedish).Uppsala, Sweden. http://www.artfakta.se/Artfaktablad/Hapalopilus_Croceus_121.pdf
Gärdenfors, U (ed), 2010. Red-listed Species in Sweden 2010. ArtDatabanken, SLU, Uppsala.
Kålås J A, Viken V, Henriksen S and. Skjelseth S (eds). 2010. Norwegian Biodiversity Information Centre, Norway. 480 pages.
Otto P, 2011. Ecology and chorology of 51 selected fungal species. Draft, Leipzig (unpublished)
Sunhede, S. 1997. Vedsvampar på ek – 5. Saffransticka. [Wood fungi on oak – 5.
Hapalopilus croceus]. Ekbladet 12: 19-23.S
Sunhede, S. & Vasiliauskas, R. 2003. Hotade tickor på ek i Litauen. [Threatenad polypores on oak in Lithuania]. Svensk Bot. Tidskr. 97: 252-265.