Life Beneath the Snow
By Emily Ruttan
With the onset of cold weather and shorter days, the forests, covered in snow, may seem lifeless. Wildlife have found many ways to adapt to the harsh winter conditions. Some animals leave for warmer places, while others find a cozy den to hibernate in until warmer weather returns. However, some animals stay right under our noses. Just below our feet, under the snow, is teeming with life. Welcome to the Subnivean Zone!
What is the Subnivean Zone?
The space in between the snow and the ground is called the subnivean zone. The subnivean zone is formed in two ways:
- As snow falls and it piles onto dense vegetation, rocks, branches and logs, the snow does not directly touch the ground. This makes a layer of space between the ground and snow.
- The ground is warmer than the surrounding air because it gets heat from the earth’s core, causing the lowest layer of snow to turn from a solid into water vapour! The water vapour then re-freezes creating a hard roof-like structure with space underneath.
The hidden habitat is almost like an apartment building! The subnivean zone has a maze of tunnels and rooms, and it is not only used for shelter from the cold –some small mammals even use these spaces to store food, use the washroom, sleep, and even eat.
Who lives in the Subnivean Zone?
Many of New Brunswick’s small mammals use this hidden habitat. Chipmunks, Deer Mice, Shrews and Pine Marten, among many others. Without the Subnivean space, animals that stay throughout the winter months would have no home, no safe space to eat or sleep – it ultimately affects their survival.
Not only do small mammals rely on this habitat but larger mammals and birds like Foxes, Owls and Coyotes do, too. They can use their keen sense of hearing to find food in the subnivean zone, and this is an extremely important food source.
Climate Change and the Underground Habitat
Climate change is causing the weather to swing in extremes, especially in the winter months. An increase in warmer temperatures is causing less snowfall, and shorter winters.
The biggest threats that climate change poses to the subnivean zone are:
- The length of time the Subnivean zone exists
- The quality of habitat and shelter for the subnivean dwellers
As the winters are getting warmer, the amount of precipitation coming down in the form of snow is decreasing and instead, is coming in the form of rain. Think of this as a “snow drought”. With a lack of snow, the subnivean dwellers do not have enough room to be underneath the snow and it can make them colder! Without the shelter of the habitat, they are vulnerable to cold temperatures and wind. Increasing rain and snow melt can also flood the tunnels and ruin food that has been stored under the snow.
Although the subnivean zone is under stress because of climate change, there is one important step that can help the animals – Protected Areas!
- Provide enough space for wildlife to adapt to a changing environment.
- Lessen the impacts of climate change.
- Keep habitats connected and stop habitat loss.
- Reduce the impact of extreme weather.
CPAWS New Brunswick works across the province to encourage our government to protect more nature through protected areas. Click here to learn more.