A GLOBALLY rare fungus discovered for the first time in Scotland by scientists assessing restoration work on a temperate rainforest created a conservation conundrum.

The Chamonixia caespitosa, a type of truffle, is typically only found in the Alps and Scandinavia and has only been recorded once in the UK, in northern Wales, just seven years ago.

It was discovered by specialist ecologists from the James Hutton Institute as part of work assessing restoration of a Site of Special Scientific Interest (SSSI) in Glen Creran, managed by Forestry and Land Scotland (FLS).

Restoration of the Atlantic rainforest involves removing planted spruce trees from it. But as the fungus forms a symbiotic relationship with the spruce and cannot survive without it, removing the spruce kills the fungus.

Dr Andy Taylor, a molecular fungal ecologist at the Hutton, who is leading the work, said: “It’s hugely exciting to find this fungus in Scotland. But it raises interesting questions about the restoration of our globally important but increasingly rare and threatened rainforest habitats.

“We’re looking at a globally rare fungal species that exists only with non-native spruce trees that were introduced into a highly valuable native habitat. A key question for us now is how prevalent this fungus is at this site – and perhaps more importantly does it occur elsewhere – and should its presence be taken into consideration when restoring these sites?”

Colin Edwards, FLS environment manager, added: “This finding underlines the importance of research into the effectiveness of rainforest restoration work. It highlights the degrees of complexity with which anyone involved in restoration work has to contend.”

The truffle, which has only been recorded in 160 places worldwide, was found during DNA analysis of soil samples taken from the Glen Creran site as part of Scottish Government-funded work with FLS assessing the effectiveness of ongoing rainforest restoration work.

It’s not known how the fungus, which is usually spread by animals, digging up and consuming the truffles, got into Glen Creran.

But Dr Taylor says the team were “incredibly lucky” to find it. “From 42 sample sites at Glen Creran, we have generated some 300,000 fungal DNA sequences, which can be grouped into 1,985 different fungal species,” he said. “Just three of those sequences, from one single sample, came from Chamonixia caespitosa, which means that we were incredibly lucky to find it. But without further work, we can’t tell how widespread it actually is.”

The restoration work in Glen Creran, which is continuing and prioritising the rainforest habitat, is part of wider restoration efforts focused on plantations on ancient woodland sites (PAWS). These ancient sites are at least 250 years old, but from the 1950s to 1980s, they were planted over with conifer trees.

Some of these sites, including the one at Glen Creran, were part of an Atlantic rainforest habitat that once spread along the Atlantic coastline of Europe. In Scotland, it is estimated the habitat now covers just 30,325 ha, with 21 per cent of sites having been planted over with conifer.

“Our assessment of these sites is now telling us a lot about these woodlands that we didn’t know, including making discoveries like the Chamonixia caespitosa,” added Dr Taylor. “Thanks to the analytic techniques that we now use, where we can analyse DNA in soils to see what’s there in incredible detail, we expect to find more.”