Vegetation above the treeline has increased significantly in most of the European mountain ranges. On the other hand, unique Alpine plants are in danger of disappearing forever.

We are all familiar with the images of melting glaciers. They have even become the symbol of climate change. This decrease in the amount of ice that crowns the Alps, among other places, is clearly visible from space. But this isn’t even the biggest change, researchers say in a new study. Because if you look closely at the European mountain ranges, you will see that, just like the North Pole, they are becoming more and more green.

Study

In a new study, scientists examined the changes in snow cover and vegetation using satellite data between the period of 1984 and 2021. And that’s new. Previous studies have mainly focused on how global warming is affecting biodiversity in the Alps and changing the distribution of plant species. Until now, no one had made such an extensive analysis of the change in the amount of vegetation in the Alps.

greener

Global warming appears to have a particularly large effect on the Alpine region, the researchers show. Because the European mountains are getting greener. The findings show that vegetation has increased above the treeline in nearly 80 percent of the Alps. “The scale of the change is absolutely enormous,” said researcher Sabine Rumpf.

Causes

It is not the first time that scientists have noticed such ‘greening’. This has already been observed in the Arctic. Why green the Alps now? “The Alps are getting greener as plants colonize new areas,” Rumpf explains. “The vegetation is also getting denser and taller.” According to the researchers, the increase in plant biomass is mainly due to changes in precipitation and longer flowering periods due to rising temperatures.

Bad news

The fact that the Alps are now getting greener is not good news. Because this means that unique local species are in danger of disappearing. “Alpine plants are adapted to harsh conditions, but they are not very competitive,” says Rumpf. “As environmental conditions change, these specialized species lose their advantage and are outcompeted. The unique biodiversity of the Alps is therefore under considerable pressure.”

“The unique biodiversity of the Alps is under considerable pressure”

snow cover

In contrast to the vegetation, the amount of snow above the tree line has changed only slightly since 1984. This does not alter the fact that the snow cover is also decreasing, albeit only slightly so far. For example, the researchers found that snow cover had decreased significantly in nearly 10 percent of the area. That may not sound like much, but the researchers emphasize that this is a worrying trend. “Previous analyzes of satellite data had not noticed such a trend,” explains researcher Antoine Guisan. “This could be because the resolution of the satellite images was insufficient or because the analysis periods were too short.”

Effects

As global warming continues, the Alps will turn less white and more green, the researchers warn. And that has far-reaching consequences. This creates a vicious circle, for example. “Greener mountains reflect less sunlight and therefore lead to further warming,” Rumpf said. “This in turn leads to less reflective ice.” But that’s not all. Climate change is causing glaciers to languish and permafrost to thaw, causing landslides and disastrous mudslides. Finally, Rumpf emphasizes the important role of snow and ice from the Alps for drinking water supply, recreation and tourism.

All in all, the study shows conclusively that the European Alps are also subject to considerable change. It emphasizes that climate change is not only happening far away, but also closer to home. This was also apparent from an earlier study, in which researchers discovered that much of the glacial ice in the Alps is already doomed: no matter how hard we try to reduce our greenhouse gas emissions, the Alps will in any case be about the same size by 2050. have lost half of their current glacier volume.