The Trouble With Lichen

16.3.21

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This is the unedited original of an article written for and first published in The Professional Mountaineer

Rare lichen. The Trouble With Lichen. Lichen Chimney, Lichen Slab, Lichen Wall, Lichen Groove. Profound Lichen. The abundance of lichen related route names that can be found in the guidebooks from North Wales to the grit is a fitting testament as to how fundamental these organisms are to the climbing experience. Wherever there are crags, there is lichen. Wherever there are crags, there is climbing. Climbers and lichens are inextricably linked, existing in the same vertical world, exposed to the elements and clinging to the rock.

Biologically, lichens are fascinating. A partnership between fungi and algae - the former deriving its energy from and offering protection to the latter - the lichen relationship was the very thing for which the word ‘symbiosis’ was invented. It’s this unique ecology, carrying the food source within the body, that allows lichens to survive where nothing else can, gripping onto bare rock faces from the tropics to the poles. They are fantastically diverse; well over a thousand lichen species are known in the UK, with new ones still being identified.

Once you begin to really see lichens, they appear everywhere. An otherwise featureless boulder is suddenly revealed to be bursting with life. White smudges become crustose Ochrolechia, generic ‘moss’ morphs into foliose Parmelia. Strange coralline growths turn out to be fruticose Sphaerophorus and Stereocaulon. The sense of discovery can be intoxicating, and for many amateur naturalists the study of lichens becomes a lifelong passion. Armed with a guidebook and a hand lens, with each new diagnostic feature learned a door is unlocked to a new level of diversity. One lichen becomes three, each with a subtly different morphology and ecology. With a careful eye, overlooked species can be found in the most benign places, like miraculously finding a new three-star route, unclimbed, at your local crag.

Some lichens are remarkably abundant. Every sea cliff aficionado is familiar with the stiff tufts of Ramalina siliquosa - Sea Ivory - that carpets the upper pitches of Gogarth and Bosigran, while no Mountain Leader trainee gets away without learning to recognise Rhizocarpon geographicum, the Map Lichen. Others are harder to find. The Golden Hair Lichen Teleoschistes flavicans, once common, can now only be found in scattered sites above the cliffs of Anglesey, Pembroke, Lundy, and West Penwith. Over a hundred lichens are listed as rare or nationally scarce in Cornwall alone, many either threatened or nearing extinction due to habitat loss and pollution. More still are almost certainly yet to be discovered, in existential peril even before reaching the record books.

Climbers tend to be an ecologically aware group of people, but their relationship with their fellow cliff lovers can sometimes be a strained one. Lichens can obscure key holds and gear placements. They can be extremely slippery when wet, and the removal of lichens during the development of new routes, and the cleaning of old ones, is commonplace. Once cleaned, regular traffic on popular lines can prevent populations from recovering but the long-term impact of climbing on lichen communities is still not fully understood. While little research appears to have been carried out in the UK, studies from crags around the world have returned mixed results. Many indicate highly localised reduction in lichen biodiversity where climbers are active. Others show no effect at all, while some even show an increase in diversity (although this is likely due to the fact that the pocketed, featured rock preferred by climbers also supports more lichen species, rather than the growth-promoting properties of sweat, chalk, and rubber....). From ecosystem to ecosystem, rock type to rock type, the scenario changes and, as is often the case in ecology, hard and fast rules are hard to come by amongst myriad interacting factors.

So, what to do? To get the wire brush out on your new project or to leave well alone? The situation is undoubtedly complex, with no clear solution. Encouragingly, it appears likely that the lichen species most at risk of extermination are also the least likely to be removed by climbers - lichens that cause the greatest inconvenience are those that are also highly abundant - but this should be assessed on a crag-by-crag basis. You never know what might be hiding in plain sight right next to that critical crimp. It is perhaps helpful for climbers to know that, by and large, lichenologists are a friendly bunch and contributions to the British Lichen Society database are encouraged. New records of interesting species from the hard-to-reach places that rock climbers usually frequent are likely to be warmly welcomed. Lichen identification is not always trivial, but a quick email and a photograph of unusual specimens can occasionally yield a classification on the spot. Where more detailed investigation is required, there’s always the chance that you might have something exciting on your hands!

Indeed, much talk of lichens in the climbing community often revolves around whether or not we should be removing lichens from routes, but there is so much more to lichens than being just an inconvenience. Perhaps if we learn to love these fascinating organisms we may find that we no longer want to remove them quite as much, instead choosing to interact with these tenacious residents of our cliffs in the same way we might approach difficult or loose terrain: with care, respect, and an appreciation for the challenge that they present to climbers and naturalists alike.