Picturesque locations such as the Cairngorms may be easy on the eye, but hidden from plain sight is what conservationists call the ‘escalator to extinction’. And now, botany experts Dr Aline Finger and Martine Borge are not only highlighting this disturbing dichotomy, but making tracks to end the threat to plant species entirely

Head to the Cairngorms this weekend and there’s a good chance you might spot some red deer, red squirrels or a golden eagle.

It’s also very likely you’ll see one of Scotland’s more common species: the Munro-bagger. But if it’s plants you are into, and specifically Cicerbita alpina, your chances of success are not so good. You might even say they are bleak.

In case you are not familiar with it, the Cicerbita alpina – common name: alpine blue sow thistle – is a beautiful little plant. Some 80cm high, the tiny triangular blue flowers are clustered at the top of a single stem and at this time of year, they are looking their best.

A relic of the Ice Age, there was a time when you could have spotted them across the Mar Lodge estate in the Cairngorms and on hills and mountains across the country. But not anymore. A tiny part of the estate is one of its last homes in Scotland.

That grim fact is the reason Aline Finger and Martine Borge have spent the last few days up on the hills of the Mar Lodge estate. Finger and Borge both work for the Royal Botanic Garden Edinburgh but you are just as likely to find them out in the wild and beautiful countryside of the Cairngorms because that is where the frontline of their work is.

Some people call places like this the “escalator to extinction” and the aim of conservationists like Finger and Borge is to stop it.

The nature of the women’s work means it’s not the easiest thing in the world to track them down but when they finally get some mobile reception, they speak about the problem they are trying to tackle.

The two women work in slightly different disciplines – Finger is a conservation geneticist while Borge is a native plants horticulturist – but their work dovetails beautifully. It is science and horticulture spliced together to create a new species.

Thistle do nicely

MOST of their work this week has been looking closely at the few remote spots where alpine blue sow thistle is still growing. Until last October, the plant grew in only four places on the estate, all of which were tiny ledges that are inaccessible to sheep and deer, which find them pretty delicious.

Borge says it’s hard not to feel sad when you see the last little blue flowers clinging to ledges. “They are so charismatic,” she says, “and you feel attached to the plants you work with.”

However, last autumn, the women took an important step forward in their efforts to save the plant in Scotland. Along with a team of volunteers, they planted 900 Cicerbita alpina at Mar Lodge and two other sites: Glenfeshie and Glenlochay.

Using material they had grown at the Royal Botanic Garden Edinburgh, the aim was to boost the populations that are already there and hopefully improve their health and diversity.

The hope, says Borge, is that the plants will grow into self-sustaining populations that can withstand the threats they face now and in the future – in other words, those hungry deer and climate change. If anyone still doubts it, the scale of the threat – and the consequences – were made even clearer this week when temperatures in Britain hit new record highs and houses in the south of England were destroyed by wildfires.

It also means – in Scotland and around the world – that some species of plants and animals that thrive in certain temperatures are being driven higher and higher to escape the warming effect: it’s the so-called escalator to extinction because eventually the plants and animals will reach the top and run out of places to go.

Alpine devastation

ONE person who has seen this for herself is the plant ecologist Sarah Watts, a researcher at Stirling University, who has just completed a study into how climate change is affecting some of Scotland’s rare alpine plants.

What she and her colleagues found when they looked at the slopes of the Ben Lawers range in the southern Highlands was that species such as snow pearlwort, drooping saxifrage and mountain sandwort – which thrive in cool, high-altitude conditions – have been retreating higher up the hills.

The snow pearlwort is of particular concern. Such is its decline since the 1990s – 66 per cent – that its conservation status has been moved from “vulnerable” to “endangered”.

The Botanical Society of Britain and Ireland says it is the first vascular plant (a grouping that includes flowering plants and ferns) to become endangered due to climate change. The problem, says Watts, is that species like this are moving further north and higher up to survive. But eventually they’ll reach the top.

She says one of the hopes for snow pearlwort and other at-risk species lies in places such as the Royal Botanic Garden Edinburgh preserving the species and reintroducing them to the wild, which is where Aline Finger and Martine Borge come in. Over the last few days, the two women have been working at two sites on the Mar Lodge estate collecting data on the alpine blue sow thistles they planted last year. In all, they have planted at 12 sites over the last five years.

Borge – who grew up in Norway and discovered her love for plants when she visited the mountains there – says there is deep concern for the alpine blue sow thistle, which has been grown at the Royal Botanic Garden Edinburgh since 1999.

“The species is nationally rare and classed as vulnerable in the UK,” she says.

“But through our focused genetic research, conservation horticulture and targeted land management, it’s become a flagship for threatened species’ recovery.”

She adds that the thistle is closely related to the garden lettuce, which is the reason the sheep and deer absolutely love it. It is also the reason the surviving plants are on inaccessible ledges because sheep and deer cannot reach them.

Finger explains more of the nature of the problem they face. “In 2017,” she says, “fewer than 100 of the plants remained in the whole of the UK and all of them found were in Scotland, at four isolated sites in the Cairngorms: Caenlochan, Corrie Fee, Corrie Kander and Lochnagar.”

Professor Alistair Jump, who took part in the recent Stirling research, says such plants are effectively canaries in the coal mine for escalating climate change and indicate the threats to biodiversity we may face in the coming decades.

Both Finger and Borge say they are deeply worried by the situation. “Around two in five plant species around the world are already threatened with extinction,” says Borge.

“In addition, climate change, which is already ranked as the third-highest threat to biodiversity, could greatly increase the proportion of species at risk of extinction in the second half of the century, particularly in tandem with habitat loss and fragmentation.”

Human touch

Finger adds that it seems likely that, in some cases, only human intervention can prevent extinctions. “Without human intervention,” she says, “the long-term persistence of many rare plant species seems unlikely. In Scotland alone, about 200 species are currently of conservation concern. A lot of these species are scattered in the Scottish landscape as small populations, isolated from each other by unsuitable habitat, and limited opportunities to expand naturally.”

One of the possible answers is the kind of work which the Royal Botanic Garden Edinburgh is now engaged in. The Scottish Rare Plants project where Borge works has some 85 per cent of Scotland’s threatened species growing there and Borge’s job is to look after them. The great joy for her is seeing the plants emerging and growing but the long-term aim is get some of the plants back out into the wild and establish heathy populations.

Borge says that there is an increasing need for the kind of work she and her colleagues are doing. “Increasing the number of remaining plants and creating or maintaining connectivity between them (through the exchange of pollen or seed between areas) can halt fitness declines and the extinction of small populations,” she says.

“Given that in some cases habitat conservation may simply no longer be sufficient to prevent declines, there’s an increasing need for conservation translocations, the intentional movement of species for conservation purposes, as a measure of last resort.

“Small populations are also often of poor genetic health so we’re working to restore the genetic health of small populations in combination with translocating them into new sites. These measures will give plants the best chance to persist in the Scottish landscape and adapt to future challenges, such as climate or other environmental change.”

The challenges she mentions do worry Borge. We have a lot of beautiful, wild spaces in Scotland, she says, but actually a lot of those spaces are grazed by animals and the result is that they can be bare and botanically poor.

The work they do is also tricky – sometimes the only way they can see some of the plants they are observing is by using a drone.

The project last year to plant out hundreds of alpine blue sow thistles was also extremely challenging. The preparations were meticulous. First, the roots of each plant were washed to remove all traces of soil and possible pathogens. They were then carefully packed and made ready to be transported. Borge and her colleagues also needed to be prepared, which meant climbing helmets, waterproof clothing – and midge nets, of course.

Borge says it can be physically demanding work, with the planting locations sometimes only accessible with ropes, but she is constantly motivated by the plants.

“Despite the challenges,” she says, “ensuring that these plants are translocated to new mountain spots gives this tenacious species its best chance of long-term survival.”

For conservationists like Borge and Watts at Stirling, the need for action is urgent but their work goes back a long way. Watts, a former seasonal ecologist with the National Trust for Scotland, has spent 12 years monitoring 10 rare species growing on Ben Lawers, adding to a data set that goes back 40 years. She says the research indicates a rapid loss of biodiversity.

“It 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 says.

Watts’s colleague Professor Jump also believes their findings contain a serious warning. “In the context of the interacting climate change and biodiversity crises,” he says, “this research has worrying global implications.

“It shows that low-latitude, arctic-alpine plant populations already situated at maximum local elevations are effectively on the elevator to extinction.”

Sadly, the elevator is doing its work not just in Scotland but around the world. A project in Peru has been monitoring tropical birds that live at high elevation in a south-eastern area of the country called Cerro de Pantiacolla.

In 2018, a team from the University of British Columbia in Vancouver found that, of the 16 species that had previously lived at high elevations in the study area, eight of them had apparently disappeared. No trace of them could be found. They had reached the top of the escalator.

‘One in four’ threat

RESEARCH by Stanford University in 2021 also warned that the escalator effect could lead to the extinction of up to one in four of the species of alpine plant found on four glaciers in the Italian Alps, including mossy saxifrage, purple mountain saxifrage, and mignonette-leaved bittercress.

Dr Gianalberto Losapio, an ecologist at Stanford, said the effect was likely to be seen elsewhere in the world as well. “I think we can be relatively confident that our results can be extended to elsewhere in the Alps and other mountain ecosystems, like the Himalayas, the Karakoram and the Andes,” he said.

All of this is deeply concerning for conservationists like Borge and Finger, but, armed with climbing rope and gloves, they are passionate about the chances of making progress.

One positive development is the Biomes project at the Royal Botanic Garden Edinburgh which will restore and develop the greenhouses that contain around 4,000 species of plant, including many that are endangered or extinct in their native habitats.

The ultimate aim is to hold in its collections 75% of the plants that are threatened as a kind of insurance policy – a kind of hope.

The Royal Botanic Garden Edinburgh is also involved in other projects which hold out some hope in the fight against climate change. For example, it has created a “rain garden” in an area prone to flooding in collaboration with Heriot-Watt University and is experimenting there with different types of soil and different plants with the aim of discovering which plants could be used to mitigate the effects of flooding and heavy rainfall. Plants suffer because of climate change but they can also be part of the solution.

As far as Borge is concerned, there is also a bigger picture to see which is learning not to take plants for granted. Climbing the hills and mountains of the Cairngorms to preserve the alpine blue sow thistle is good for the plant and the planet – but it is also good for her too.

Feeling connected to plants like the alpine blue is good for your mental health and wellbeing, she says. “I’ve always felt connected to the vegetation around us,” she adds, and she also believes we have so much to learn from them.

Here we are burning oil and coal and generally messing things up while plants take a more sensible route. Plants are making using of renewable resources all the time, says Borge. They’re just doing their thing.