Out of the estimated millions of species belonging to the fungal kingdom, only an approximate 14,000 have been described. And due to loss of habitat from the Climate Crisis and human disturbance, some of these currently described species are considered endangered by the IUCN Red List of Threatened Species. Together, we will take a biweekly look at one of these endangered species and discuss the facts of both the fungal specimen and its conservation.
Native to Northeast America is an endangered mushroom-producing species named Echinodontium ballouii. There are only around half a dozen species in this genus described worldwide, leaving some to colloquially refer to it as a genus of “living fossils.” This specific species only grows on one species of tree in Northeast America, the Atlantic White Cedar (Chamaecyparis thyoides). This mushroom is considered a biotroph that becomes necrotrophic in its later life cycle, which can take up to 40 years. While it is classified as “parasitic,” the goal is not to kill the host plant, as it is in fungi that are solely necrotrophic. Rather, this species keeps the host alive while establishing itself in its tissue.
The main reason for its endangered classification is the destruction of its host species for logging purposes. While its host species is no longer used as heavily for logging and is classified as “Least Concern,” ballouii seems to have never recovered from the effects of logging and an estimated 250 individuals or less exist today, and have only been observed growing on 20 trees. This is likely due to the fact that this is an old-growth polypore, meaning that the production of fruiting bodies can take up to 40 years. This mushroom was thought to be deadly to Atlantic White Cedar, but it is unlikely that this is the case. The greatest threats to Atlantic White Cedar are logging and pollution/draining of its natural wetland habitat. This mushroom was also thought to be totally extinct for decades, before being found again in the early 2000s.
There are many species of old growth polypores similar to this one under threat of extinction. This is because the destruction of old growth forests had led not just to the decline of tree species, but also to the endangerment and, in some cases, total extinction of the old growth mushrooms that grow on them. Even in cases like ballouii, where the species is parasitic, old growth polypores have amazing potential to teach us about the life cycle and genetics of fungi.
REVIEWED BY: Blaise Paine, Malfoy Kimmel, Jonah Fliegelman, Kenzie Doherty
