Climate change threatens Scotland’s rare mountain habitat

Snow beds typically occur 600 metres above sea level, on the sloping headwalls of shaded corries. Few plants can tolerate prolonged periods of snow cover, but a few specialised plants including bryophytes, mosses and liverworts have adapted to survive in these conditions.

We’ve recently conducted some research at Ben Lawers National Nature Reserve on snow beds, which has shown that one of the most extreme habitats in Scotland is under threat from climate change.

Thanks to the range of unusual habitats which occur on Ben Lawers NNR, an exceptional variety of these rare plant species are found in this location. Over 300 species have been recorded, almost one-third of the British total – including many rarities which makes the reserve of national importance.

Dr Oliver Moore, an expert bryologist, recently revisited high altitude study areas on Ben Lawers set up in 2008 and 2010. He recorded a decline in several species of liverworts, which grow together to form a black mat. There were increases in some commoner mosses, such as Racomitrium, and of grasses. The increase in these plants suggests there have been shorter periods of snow cover. With longer growing seasons, these more robust plants may out-compete the specialised bryophytes.

Helen Cole, Senior Ranger Naturalist for the National Trust for Scotland at Ben Lawers NNR, said: ‘This habitat could well be one of the most vulnerable at Ben Lawers, as a changing climate leads to shorter and more erratic periods of snow cover. Whilst continued monitoring will track changes in vegetation, the Trust must consider whether there are management techniques which could conserve these rare plants communities.’

Read more about our conservation work on Ben Lawers