Climate change blamed for declines in mountain plants

Long-lying snow patches such as these on Ben Lawers can be key to mountain species' survival

Climate change has likely led to the decline of some of Scotland's mountain plants, according to new research.

Scientists said many of the species relied on snow cover remaining high on hills until late spring and even summer to ensure a moist environment.

They also said plants that thrived on lower ground in warmer conditions were spreading to mountain habitats.

Species found to be in decline include snow pearlwort, alpine lady-fern and alpine speedwell.

The research by the Botanical Society of Britain and Ireland (BSBI) has taken 20 years to complete and has been published in the new Plant Atlas.

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Data used to produce the report included more than three million plant records of 2,555 species collected by hundreds of botanists across Scotland.

Climate change, habitat loss and the spread of non-native species were found to key threats to the health of British and Irish native plants.

BSBI said devastating losses of species in Scotland were among the findings.

Almost the entire British population of snow pearlwort is found on Ben Lawers, but half of the Perthshire mountain's known colonies have disappeared over the last 40 years.

Snow pearlwort is among Scottish plants found to be in decline

The research also suggested there had been a loss of meadow plants since the 1950s due to the use of nitrogen fertilisers and damp fields being drained.

Peatbog and moorland were other habitats deemed to be at threat - particularly from the spread of Sitka spruce, a non-native tree.

Matt Harding, BSBI's Scotland officer, said: "Sitka spruce had the greatest increase in range of any species covered by Plant Atlas 2020.

"Its ability to regenerate successfully on peaty soils that are vital for native biodiversity and carbon sequestration means that future planting will need to be carefully managed to ensure that these important peatland habitats are protected."

BSBI chief executive Julia Hanmer said: "Plant Atlas 2020 presents a powerful and concerning insight into the changing distributions of our wild plants."

Last summer, University of Stirling researchers said climate change had pushed Scotland's rare arctic-alpine plants to the brink of extinction.

Snow pearlwort, drooping saxifrage and mountain sandwort - which thrive in cool, high-altitude conditions - were found to be retreating higher up slopes.

The researchers said the species were at risk of eventually running out of anywhere to grow and would disappear.

Higher temperatures, reduced snow cover and lowland plants were identified as threats.