When we think of snow, we usually imagine a silent, frozen landscape – clean, cold, and lifeless. But under a microscope, the reality is different.
New research from the SNOWLIFE project reveals that even seasonal snow patches in lowland regions host surprisingly rich communities of microscopic life. These frozen environments, part of what scientists call the cryosphere, are not just important for climate regulation – they are ecosystems in their own right.
While life on glaciers and permanent snowfields has been studied for decades, much less is known about the snow that appears each winter and disappears in spring. To explore this hidden world, researchers from Klaipeda University, Lithuania and Adam Mickiewicz University in Poland carried out a three-year study across Lithuania, Latvia, and Estonia, focusing on patches of snow that remain in forests in late winter and early spring.
What they found challenges common assumptions: each of the 200 snow patches they studied contained life.
Under the microscope, snow samples revealed a diverse community of tiny organisms, including rotifers, nematodes, and tardigrades (often called “water bears”), as well as mites and other small arthropods. Many of these creatures are less than a millimetre in size, which makes them invisible to the naked eye.
The study identified more than 30 species of rotifers, including some that are rarely recorded in Europe. Some of them could also be completely new, previously unrecorded species. Another interesting finding is that many of these organisms are bridge in colour – orange, red, or yellow – which could be their evolutionary solution to strong ultraviolet radiation reflected by the snow.
A very surprising finding in this study is that these living communities do not depend heavily on algae, which are a key food source in polar and alpine snow ecosystems. Instead, the study suggests that in lowland environments, microscopic animals rely on organic material coming from surrounding vegetation. Snow patches located under tree cover were found to host more abundant life – a nod to the importance of forests in shaping these hidden ecosystems.
These findings come at a critical time: seasonal snow is one of the most fragile components of the cryosphere and is disappearing rapidly as winters become shorter and warmer. If snow patches support their own unique biodiversity, their loss could have consequences that we’re not aware of yet.
