Rising temperatures lead to new plant species in tundra

A tundra region in Mongolia, 2,000 kilometres northwest of Ulan Bator. Keystone

An international study with Swiss participation has shown that warmer temperatures in the Arctic tundra are changing the type and size of plants growing in the region – a phenomenon that could potentially accelerate climate warming even further.

The researchers – including scientists from University of Zurich and the WSL Institute for Snow and Avalanche Research SLF – concluded from 30 years of data that “climate warming” is having a clear effect on Arctic flora. The results of the study were published this week in the scientific journal Nature.

Using observations from some 120 points in the Arctic Circle, as well as at high altitudes in the Alps (where conditions are similar), they found that not only are traditional plant species growing taller than 30 years ago, but that higher-growing species native to warmer regions have also spread to the tundra.

“Plant species from lower altitudes are spreading to higher altitudes due to climate warming,” said SLF mountain ecologist Christian Rixen in a press releaseExternal link.

Vicious cycle

The authors do not shy away from pointing to a direct causal link with climate change, noting that over the past three decades, temperatures in the regions studies have risen by around 1 degree Celsius in summer and 1.5 degrees Celsius in winter.

“The Arctic is warming up faster than almost anywhere else on earth”, the researchers say.

As a result, they also predict that the growth is far from over: the researchers estimate that the height of plant communities in the tundra could spurt again by an average of 20-60% by the end of the century.

In addition to the warming itself, increased soil moisture due to sharp increases in precipitation, which tend to accompany rising temperatures, could also contribute to these changes in vegetation.

According to the SLF press release, one potential impact of these changes could be that more snow becomes trapped around the taller plants in winter, insulating the active layer of permafrost – one of the world’s major carbon stores. Thawing permafrost could mean the release of greenhouse gases carbon dioxide and methane, further accelerating climate warming.