You may have either not heard of the oak polypore (syn: Buglossoporus pulvinus), or never come across it in the field. That would be because it is very rare in the UK. So rare, in fact, that it is a protected species under Schedule 8 of the Wildlife and Contryside Act 1981 in the UK.
This fungus is principally found in the southern half of England, where it can be seen upon mature and veteran oaks in old growth woodlands and pastures where exposed heartwood is present. However, research suggests that the fungus may be so infrequent that it has suffered from genetic drift (as a result of inbreeding) – only four mating alleles were found across six study sites where the fungus exists. This may be as a result of either the loss of old growth woodland stands and veteran oaks within wood pasture, or because the fungus is a very poor competitor when paired with other fungi – it grows slowly and in narrow range of environmental conditions, and simply is not aggressive enough in its competitive ability when other fungi are present.
Therefore, if we are to assist with the conservation of this rare fungus, we need to be conserving mature, veteran, and ancient oaks, perhaps with exposed heartwood, and also retaining older woodland stands. Perhaps, where there is a lack of a mature or maturing oak population, veteranisation techniques may assist with the creation of viable habitat for the fungus. However, given it’s suspected inbreeding and lack of competitive ability, conservation management may be challenging.
Interestingly, the fungus was supposedly found on a living beech tree (Fagus sylvatica) at Woodstock, England, in 1949. This contrasts with other sources, that states it can only be found on Quercus species.
Cartwright, K. (1951) Polyporus quercinus on Fagus sylvatica. Transactions of the British Mycological Society. 34 (4). pp.604-606.
Crockatt, M. (2008) Ecology of the Rare Oak Polypore Piptoporus Quercinus and the Tooth Fungi Hericium Cirrhatum, H. Coralloides, and H. Erinaceus in the UK. Doctor of Philosophy thesis. Cardiff University.
Crockatt, M., Campbell, A., Allum, L., Ainsworth, A., & Boddy, L. (2010) The rare oak polypore Piptoporus quercinus: Population structure, spore germination and growth. Fungal Ecology. 3 (2). p94-106.
Overall, A., 2010. Fungi Royale: Some interesting larger fungi of the Royal Parks-Part 1. Field Mycology. 11 (3). p101-104.
Rogers Mushrooms. (2016) Buglossoporus pulvinus. [Online] Available at: http://www.rogersmushrooms.com/gallery/DisplayBlock~bid~12194~gid~~source~gallerydefault.asp [Accessed: 24th January 2016].
Wald, P., Crockatt, M., Gray, V. and Boddy, L., 2004. Growth and interspecific interactions of the rare oak polypore Piptoporus quercinus. Mycological Research. 108 (2). p189-197.