Alpine flowers could become extinct after glaciers disappear as more competitive species settle higher ground up the mountain, a new study has warned.
Glaciers are retreating at unprecedented levels, revealing new land for plant growth, which benefits delicate alpine species in the short term. However, these early pioneers – some of whom are endangered – will soon be threatened by more invasive species, driving them out of the remaining habitat and reducing overall biodiversity, according to the paper published in Frontiers in Ecology and Evolution.
Up to 22% of species surveyed on four glaciers in the Italian Alps have disappeared from the region once the glaciers are gone, the researchers found. Endemic plants such as mossy saxifrage, purple mountain saxifrage and bitter cress with a mignonette color are likely to become extinct 150 years after the glaciers became extinct, according to lead researcher Dr. Gianalberto Losapio, ecologist from Stanford University.
Advanced environments are highly sensitive to global warming, and mountain species are subject to “extinction climbs”. They need to move to a higher altitude habitat as the weather warms up, but there is no more room to do this. “I think we can be relatively confident that our products can be extended to other parts of the Alps and other mountain ecosystems, such as the Himalayas, the Karakoram and the Andes,” said Losapio.
The researchers found that 51% of species were affected by glaciers – 29% of species would thrive and 22% could become extinct locally. Rare, special species that have adapted to grow in the harshest conditions (for example by growing close to the ground so that they do not blow away) settle areas of less than 100 years after the glacier melted. After 150 years, competition grows faster, and more common species such as alpine sedges, alpine honey grasses and rugged yellow cinquefoil have a higher hand.
Alpine plants are a key component of fragile mountain ecosystems and so are likely to become extinct locally, Losapio said. “The main producers … are not just our food but fuel for the whole ecosystem – the consumers, predators, parasites, strawberries and pollination.”
Researchers used geological records to reconstruct glaciers so that they could work out when ice returned from different parts of the mountain. This information was combined with a study of 117 plant species observed in hundreds of blocks up to 50m2 in size, together with an analysis of local environmental conditions.
Geum reptans, or revenge creep, a common alpine plant is endangered due to receding glaciers. Photo: Boundaries in Ecology and evolution
They studied the Vedretta d’Amola glacier, the Western Trobio glacier, the Rutor glacier and the Vedretta di Cedec glacier. By combining databases, researchers could analyze changes over the past 5,000 years and make predictions for the future.
As to what the Italian Alps will look like in 100 years, it depends on what happens to rainfall, and there is no consensus on this. “Like the boreal forest in Scandinavia or Canada, if it rains a lot it can be a continuous forest, with wet, moist, deep, fertile soil. If it doesn’t, it will look more like the Sierra Nevada in Spain or California, ”said Losapio.
Research from the University of Zurich has previously shown that alpine plants do not keep up with climate change, with invasive species settling mountain tops faster. Botanists working in the Highlands of Scotland also found that Britain’s rarest mountain plants were fleeing higher and that grass was generally found at low altitudes.
In addition to working to reduce emissions, educating people and raising awareness about fragile mountain ecosystems could help protect those environments, according to Losapio. It would help encourage people to stick to trails and not build extra ski slopes.
Silene acaulis, called campion moss or pink cushion, is a wild flower that lives in mountains. Photo: Boundaries in Ecology and evolution
Dr Trevor Dines, a botanist at the British charity Plantlife, who was not involved in the research, said: “Our native mountain plants are very vulnerable; 44% of montane species are endangered – a higher proportion than any other habitat.
“Rock faces that are home to fragile flowers such as foamy saxifrage, mountain revenge and moss campus are now choked with grass, mosses and rushes as the fertility of the thin soil increases. Together, the parallel risks of climate change and nitrogen deposition could create the perfect storm for our delicate mountain flowers. ”
John Dunn, chief executive of Plantlife, said: “This report is valuable as the forecast allows conservationists to better predict the changes that are taking place. They don’t look positive. We need to work together to meet the challenge of both climate change and biodiversity loss and Plantlife is looking for the UN Convention’s Global Biodiversity Framework on Biological Diversity to clearly address the conservation of wild plants and fungi. . ”
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