CLIMATE change has pushed rare plants to the brink of extinction, scientists have warned.

Snow pearlwort, drooping saxifrage and mountain sandwort - which thrive in cool, high-altitude conditions - have been found to be retreating further up the slopes the Ben Lawers range in the southern Highlands, north of Loch Tay.

University of Stirling researchers say that plants could soon become extinct without intervention because they were at risk of eventually running out of anywhere to grow.

The rate of decline of snow pearlwort – 66% since the mid-1990s – has led to it being moved from ‘vulnerable’ to ‘endangered’ conservation threat status by the Botanical Society of Britain and Ireland (BSBI).

It is the first ‘vascular’ plant – a grouping that includes flowering plants and ferns – to become endangered due to climate change, the BSBI said.

The study also found that drooping saxifrage and mountain sandwort have both declined by over 50 per cent.

The Arctic-alpine plants, require a cool climate at high altitude but due to increasing global temperatures, species are moving to higher ground with drooping saxifrage now found 50 metres from the top of Ben Lawers.

Ben Lawers is the most southern point in Europe where the plant grows and it is more commonly found in areas such as the Arctic and northern Scandinavia.

Sarah Watts, a PhD researcher from the University of Stirling’s Faculty of Natural Sciences and a former seasonal ecologist with the National Trust for Scotland (NTS), has spent 12 years monitoring 10 rare species growing on Ben Lawers, adding to a data set that goes back 40 years.

Miss Watts said: “Our research signals a rapid loss of biodiversity happening right now which means that, if it’s allowed to continue on this accelerated trajectory, due to climate change, we will see the extinction of species like these.

She said the global rise in temperature due to climate change had led to lowland species colonising upland areas and outcompeting the mountain plants, reducing the area they can grow in.

Researchers have suggested expert horticulturalists working in botanical gardens could play a part in preserving the Scottish species.

The Herald:

Snow pearlwort

Ms Watts suggests that the plants are moved to other sites such as botanical gardens or more suitable mountain habitats.

Professor Alistair Jump, dean of the Faculty of Natural Sciences at the University of Stirling warned the findings have “worrying global implications”.

He said: “In the context of the interacting climate change and biodiversity crises, this research has worrying global implications. I “It shows that low-latitude, arctic-alpine plant populations already situated at maximum local elevations are effectively on the elevator to extinction.

“We face their loss from our mountains because there is no higher ground left for them to retreat to as temperatures continue to rise.

The highest mountain, Ben Lawers gives its name to the wider National Nature Reserve owned and is managed by the National Trust for Scotland.

As well as celebrity status for its rich arctic-alpine flora, Ben Lawers NNR boasts seven Munros.

Conservationists have been trying to save wildflower meadows, rare pinewood plants and arctic alpine flora from dying out in the Cairngorms.

Species such as twinflower, which has tiny, pink, bell-shaped flowers, were classed as being on the verge of extinction in the area, two years ago.

One-flowered wintergreen - one of Scotland's rarest pinewood flowers - is also at risk.

Plantlife Scotland has been leading a project to boost meadows and establish new twinflower populations.