I already mentioned it earlier, but I cannot put enough emphasis on it: snow is a blessing for plants in their struggle to survive winter.
Winter is a hard time for plant life, that is beyond question. Cold temperatures, biting winds, limited light… More than enough reasons to die. The important thing is: snow might be excluded from this list.
Although snow brings its own troubles and complexities, most of the times it might be no less than the saviour of the suffering plants.
A nice, soft blanket of snow dampens the temperatures. It ensures a stable temperature of around 0 °C, which is cold, but not too cold for plant (and animal) life. Living things underneath this blanket, like the plants we study (or lemmings or ice bears for that matter) are far away from the bad conditions outside.
Even if the open air is freezing cold, the isolating snow blanket with its trapped air inside, brings all temperatures back to the blessing 0. Until the first warm days in spring melt away the snow…
In the subarctic mountains, it is hence the so-called ‘shoulder seasons’ at the very beginning and end of winter that cause the biggest danger. Most damage is the result of periods of freezing temperatures before the first snowfall, or more rarely after snowmelt in spring.
In Belgium, snow is much more irregular. It is not often that our soils are covered in this protecting blanket. So here is my hypothesis: soil temperatures close to the surface experience in the end longer and more freezing periods in the soft climate of Belgium than in the harsh climate of Sweden, because of the more persistent snow blanket in the north.
Let me use my iButton-data from this winter to verify if that hypothesis indeed holds true!