Many of the rare arctic-alpine plants found growing on Scotland’s mountains are in retreat and teetering on the brink of extinction. Plants such as snow pearlwort, alpine lady-fern and alpine speedwell thrive in the cool conditions high on the mountains, but a Stirling University study found these plants were retreating higher up the mountain slopes.
Almost the entire British population of snow pearlwort is found on Ben Lawers in Perthshire, but two-thirds of the colonies have disappeared from the mountain over the past 40 years, while drooping saxifrage is now only found 50 metres from the top.
The plants are facing competition from warmth-loving species that usually grow at lower levels, but are now colonising higher up the slopes due to climate change. The mountain plants grow on open, gravelly habitats that depend on snow cover in late spring and even early summer, which is rapidly disappearing, causing freeze-thaws that set off landslips and rockfalls, destabilising their mountain habitat. Eventually, the native mountain plant species will run out of anywhere to escape to and will disappear.
A study of mountain plants over 30 years in the European Alps found these species also faced similar threats from climate change.
