January - snowbeds

The period of snow cover in Scotland has decreased by a third over the last 40 years, mainly due to milder autumn and spring temperatures producing less snowfall and earlier snowmelt.

Snow can lie well into the summer in the corries of Scotland’s highest mountains and some patches sometimes persist all year. This late-lying snow provides conditions that support species that would otherwise be more at home in the Arctic. Flowering plants struggle to survive in the short growing season between snow cover. Instead, the damp vegetation is dominated by a community of smaller plants, made up of specialist mosses and liverworts. Many of these species are nationally rare, including about 50 species that are either restricted to, or have their highest UK abundance in, ‘snowbed’ vegetation in the Highlands.

It is difficult to accurately predict the impact of climate change on late-lying snow cover, but it has been estimated that by 2050 there will be a 20% reduction in snow cover on our mountain tops. As the length of the growing season has increased, flowering plants are already beginning to colonise these areas. We haven’t lost any of the rare snowbed mosses and liverworts yet, but if a warmer climate causes a reduction in snow cover in Scottish mountains, this special bit of our biodiversity may be the first to disappear.

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