Bodysnatching fungi part of Trust’s rare mushroom habitat

The Strathy Strangler (Squamanita pearsonii) parasitises another fungi species, the Earthy Powdercap (Cystoderma amianthinum). Known only from a handful of sites, and globally rare, it is a biotrophic parasite of its host, meaning it keeps the host alive while robbing it of enough of its resources to maintain itself.

The lawns at Haddo House near Ellon, Aberdeenshire, have been identified as an internationally important habitat due to the high number of fungal species found there, as measured on a scale for fungal biodiversity in grasslands called the CHEGD score. CHEGD is an acronym for Clavariaceae, Hygrocybe, Entoloma, Geoglossum and Dermoloma, which are the different types of fungi that are grouped together and scored.

Along with the Strathy Strangler, the lawns have been home to up to 20 different species of waxcap mushrooms (Hygrocybe), 18 species of pink-gill mushrooms (Entoloma), and ten species of coral fungi. There are also several International Union for Conservation of Nature (IUCN) Red List of Threatened Species designated as Globally Vulnerable, like Porpolomopsis calyptriformis, known as ‘the Ballerina’ and Violet Coral (Clavaria zollingeri).

Roddy Hamilton, Countryside Ranger, said: ’The Strathy Strangler has not been seen recently, so it would be good to uncover again. It is a fascinating example of a fungi species’ adaptation, and it’s one of the more unique and curious varieties that has been found in the lawns at Haddo. It infiltrates its hosts through an underground network of mycelial threads called hyphae and takes over its host’s body, growing up its stem and robbing it of its nutrients. The spectacle only becomes apparent after the Earthy Powdercap loses its usual sandy colour, taking on a shaggy, grey appearance after the strangler has overcome its victim. Thankfully, there isn’t a risk of this strangler taking over and wiping out different mushroom species, as it seems to have, through evolution, built a relationship only with this one fungus.’

As part of our work to help protect globally vulnerable species, we are conducting surveys of various waxcap fungi grasslands, a key objective outlined in our Plan for Nature, published in 2024. This plan provides a framework and focus for nature conservation efforts and includes the actions we will take to care for the habitats and species we have responsibility for. The waxcap fungi monitoring has been supported by funding raised by players of People’s Postcode Lottery.

Roddy continued: ’Very little conservation exists for waxcaps across Scotland, except for a few locations where grasslands are managed for nature conservation, like at Haddo. Grassland meadows are generally valuable for a range of purposes, from carbon storage to ecosystem services like pollination, and are a complete ecosystem in themselves. Some agricultural methods, including the use of fertilisers on grasslands, result in habitats that are inhospitable to waxcaps. Fungi are an essential part of grassland ecosystems, and our conservation efforts aim to enhance the habitat to make it more suitable for the fungi, rather than eradicate the parasite.

’We have a management plan in place which keeps the lawn short, emulating as much as possible the sheep grazing that historically would have made it a suitable environment for waxcap fungi. We stop cutting in autumn when the fungi ’fruit,’ the period when the mushrooms and toadstools that we recognise become visible above the surface. We also don’t add any nutrients to the lawn, removing cuttings to reduce nutrients from the cycle.’

Players of People’s Postcode Lottery have supported the Love Our Nature project since 2022, which benefited from £900k last year. Further funding will support nature conservation work across a variety of different habitats, including coastal and marine areas, peatlands, wetlands, woodland, and the eight National Nature Reserves cared for by the Trust.

Head of Charities at People’s Postcode Lottery, Laura Chow, said: ’Players of People’s Postcode Lottery will be fascinated to hear about the Strathy Strangler and the important work the National Trust for Scotland is doing to enhance the natural environment where waxcap mushroom species can thrive. This work of the Trust is vital in helping to protect Scotland’s natural heritage for future generations.’

The Love Our Nature project supports our vision to care for, protect and share Scotland’s nature, beauty and heritage for everyone, as outlined in our 10-year strategy, launched in 2022.