Changes in snow cover threaten biodiversity of Arctic nature

Many plants that inhabit the northern mountains depend on the snow cover that persists until late spring or summer. Snow protects plants against winter extremes, while reducing the length of the growing season, preventing the establishment of more southern plants. This is why reduced snow cover can pose an even greater threat to Arctic plants than rising temperatures.

In a study published in the famous scientific journal Nature Climate changeResearchers from the University of Helsinki and the Finnish Environment Institute have analyzed the potential effects of temperature changes and snow cover duration on the extinction risk of northern flora. The results show that many plant species can benefit from a warmer climate, but that rapidly retiring snow cover can radiate much of the typical northern mountain flora. Many of these species are already endangered, making their conservation an urgent challenge.

"Although the importance of snow is widely recognized, winter conditions are often ignored when studying northern and mountainous regions," says Pekka Niittynen, a PhD student at the University of Toronto. Helsinki.

Help with remote sensing and satellite images

Winter data collection was very difficult, but remote sensing and satellite imagery have allowed detailed monitoring of snow cover since the 1980s.

With the help of remote sensing and species distribution models, we have shown that winter is of paramount importance to the northern nature and the future of its organisms, explains Niittynen.

Many arctic and mountain plants are specialized in growth and flowering for a very short summer. If the duration of snow cover decreases and summers lengthen, more southerly species benefit and may compete with arctic species until extinction.

According to the researchers, the climate in northern regions is changing faster than in the rest of the world, and these changes are particularly violent in winter. This makes the current results all the more significant.

Difficult to predict the effect of warming on the snow cover

"We are afraid we will not know exactly how the snow will change as the climate warms up, we can predict the temperatures accurately, but it is more difficult to predict the precipitation." "With the snow, it's even more uncertain. In some areas of Siberia For example, the amount of snow may increase due to more precipitation in winter, but the duration of the snow cover in the northern countries should be much shorter, "said Pekka Niittynen.

"Our results show that future changes in northern species populations could be abrupt, which would give rise to hard-to-predict ecological surprises, such as the rapid eradication of populations in certain areas and regions. "Invasion of flexible species in new places," says lead researcher Risto Heikkinen of the Finnish Institute of the Environment.

The buttercup glaciers and other arctic and mountain plants need big snow bags

"Many iconic species of arctic regions, such as the glacier buttercup, will decline considerably due to the changing snow," said Miska Luoto, professor of natural geography at the University of California. Helsinki.

Many of the northern mountain species thrive only in the drift zones.

"Decreasing galleries will increase the risk of extinction for plants such as snowcurd, mountain sorrel and mossy plants."

Recently published research is on plants, moss and lichen, but the results are likely to apply to many other populations of Arctic organisms. Many Arctic species are at risk of extinction if snow-dependent species do not have suitable areas in the vicinity where the snow cover will remain on the ground long enough. There are few ways to adapt to changes in snow cover in arctic areas in practice. This is why mitigation measures of climate change effects are essential to the preservation of the Nordic nature.

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More information:
Pekka Niittynen et al. Snow cover is a neglected factor in the loss of Arctic biodiversity, Nature Climate change (2018). DOI: 10.1038 / s41558-018-0311-x