Standing here on Nine Arches viaduct, 85 feet above the River Derwent on the outskirts of Gateshead, I’m sharing my view of the bare tree canopy below with a red kite that’s circling overhead.
I can appreciate why some people have an irresistible urge to head for high places. There’s a vertiginous adrenaline rush, a sense of elation. But it’s more than that. It’s about freeing the mind, albeit briefly, from everyday clutter, allowing it to take flight.
I’m wondering about cushions of moss, a miniature archipelago of green islands, growing along the viaduct parapet. Moss and rock are almost inseparable, bound by hair-like rhizoids that penetrate the granular fabric of the stone. It’s hard to imagine a more stressful environment, exposed to wind, rain, cold, heat and drought, subsisting on air, water and whatever minerals ashlar capstones provide. But these plants have a pedigree for survival in such places. Their ancestors were the first plants to colonise dry land, over 400m years ago, and still they thrive, after weathering four great mass-extinction events. Now, perhaps, they’re on the threshold of another.
I can see that one species is wall screw-moss, tiny rosettes of lime green leaves, just a few millimetres tall, still bearing last year’s withered spore capsules, with a new crop rising among them. Neat hemispheres of grey-cushioned grimmia moss are here too. Each of their leaves is tipped with a fine hair that has captured a glistening droplet of occult precipitation – last night’s fog – a clue to why they can survive drought so well.
Anthropocentric concepts of progress and beauty tend to place most value on spectacular wildlife that sits on recent twigs of the evolutionary tree. On that measure, these minute plants cannot compete with, say, orchids. But what if we ranked lineages of life forms according to durability, celebrating those that endured every physical challenge our planet can summon? Like these tough mosses: magnificent survivors.
My gaze focused, for a moment, a few inches away, thoughts half a billion years in the past. But now, away to the south, sunlight glints on the river’s ripples and a patchwork of fields emerges from the morning mist. This is the magic of high places.
• Under the Changing Skies: The Best of the Guardian’s Country Diary, 2018-2024 is published by Guardian Faber; order at guardianbookshop.com and get a 15% discount
