World-leading biological science meets the history of hill climbing on Thursday, August 19, when plant material is collected for DNA sequencing on Britain’s highest mountain. In contributing to the ground-breaking Darwin Tree of Life (DToL) initiative, a team from the Royal Botanic Garden Edinburgh (RBGE) will be marking the 250th anniversary of the first recorded ascent of Ben Nevis, by one of their own predecessors.

When James Robertson documented his ascent of Ben Nevis, on August 19,1771, it was at the behest of RBGE to record the plants he found growing on its slopes. This week, the anniversary is recognised with the collection of specimens to be processed for the Wellcome Sanger Institute-led DToL initiative: its aim, to bring fresh insight to the biodiversity of the British Isles in a genome-sequencing programme which will act as a launchpad for the ultimate ambition to sequence the DNA of all species on Earth. 

While the science may have changed in two-and-a-half centuries, the mission has broadly the same aspirations. Only by documenting and describing species, then understanding their relationships with other living organisms can we start to address the major 21st century challenges of biodiversity loss and climate change.

Simon Milne MBE, Regius Keeper of RBGE and one of the team climbing Ben Nevis explained: “In the season when James Robertson ascended Ben Nevis to document the plants he found there, he made similar documented climbs of several other highland peaks in what might be considered a precursor of ‘Munro bagging.’

“Thursday, August 19, 2021 does more than mark an anniversary, however. On the approach to COP26 in Glasgow, RBGE is one of 10 partners in the Darwin Tree of Life project to sequence the genomes of all complex living organisms to be found across Britain & Ireland. During the climb, our team will be recording and collecting specimens of interest – some flowering plants, but significantly bryophytes and lichens. 

“It is likely we will find differences to the plant biodiversity seen by Robertson. Some additional species are likely to be found on the slopes, others will have disappeared, or moved up the mountain to avoid the impact of climate change or other threats to their habitat. At a time when biodiversity is in crisis and many species are under threat from climate change, the anniversary ascent can provide crucial data to help characterise, catalogue and support the conservation of our environment.”

Lichenologist Dr Rebecca Yahr said the relevance of the fieldwork being undertaken on Ben Nevis should not be underestimated: “Lichens in the Nevis range and the wider Grampians are internationally important because of the global rarity of alpine situations in ‘hyperoceanic’ climate conditions – with a very strong influence of the mild and moist conditions caused by proximity to the sea. This is a climate that is possibly unique worldwide. On high ground, the rainfall per year reaches 3800mm per year, with annual temperatures hovering at zero near the summit.

“These lichens are still relatively poorly known, with very few specialists working on them. Those that are typical of the extremely wet and usually cold climates here are at their best development, with some stunning species such as Solorina crocea (Easy Lichen) and Stereocaulon saxatile, which looks like a miniature version of a fairy wonderland.”

The Ben Nevis lichens, along with mosses and other tiny plants are fragile, taking a long time to recover from disturbance and are very sensitive to change. So much so, these “snowbed” species, found where the snow lies late in Scottish mountains, are used as sentinels for monitoring climate change.

Professor Pete Hollingsworth, Director of Science at RBGE added: “DToL is providing an opportunity to sample species from this unique part of the global climate spectrum and investigate the ways they regulate their metabolisms and their symbiotic partnerships to deal with these extreme situations. The depth of sampling of genomes across well-documented situations is one of the incredible strengths of the programme.”

Ironically, this historic anniversary climb would have happened two days early, but for finding James Robertson’s journal. Dr Christopher Ellis, coordinating Thursday’s climb explained: “August 17 was quoted by Wikipedia’s Ben Nevis page, and this date seemed to have propagated into various other articles and reports across the web. However, this date conflicted with James Robertson’s journals. Going back to the original source, copies of Robertson’s journals are archived in the National Library of Scotland, and staff from the Library kindly located these and confirmed the date of the 19th August, which was subsequently corrected on the Wikipedia page by a colleague – so some detective work required, but the 19th August is the correct date!”