Is heavy snow a boon to nature? We dive into the cold facts

Here’s the simple recipe for a snowpack: start with a whopping serving of the white stuff. Keep temperatures below freezing for a fortnight or more. Add more snow as needed. Make witty comments to friends, like “is this Alaska or Harwich?”

Plants persevere, and are sometimes helped, by a blanket of snow. Photo by Gerry Beetham

We’ve cooked up a fine batch of snowpack on Cape Cod recently, and for nature lovers, the obvious question might be: how does this heaping frosting affect wildlife and plants? Let’s put on our snow goggles and take a look.

Harwich Conservation Trust (HCT) naturalist Tom Walker, who leads fabulous HCT tree, shrub and lichen field classes, sees benefits and drawbacks from a heavy snow cover. “A blanket of snow provides insulation so that roots and plant bases aren’t subject to temperature extremes,” he wrote. “It also will prevent frost heaves which can damage roots.”

But Walker also reported a rather unfortunate gardening event that stemmed from a significant snowfall.

“It also provides cover for voles which are rather voracious eaters of roots and bulbs,” wrote Walker. “I had a terrible experience in our garden a few years ago after a heavy snowfall. The voles had a perfect cover to eat hundreds of bulbs in my garden and then start eating the roots of our rose bushes and sampling just about everything.”

Welcome to the subnivium

In a fascinating story called “A secret ecosystem below the snow,” the City of Philadelphia’s Environmental Educator Susan Haidar writes that the “small area between the snowpack and the ground is called the subnivium. The word comes from Latin: sub meaning below, and nivis, the word for snow.”

A coyote moves through the snow at Harwich Conservation Trust’s Robert F. Smith Cold Brook Preserve. Photo by Gerry Beetham

Think of the subnivium as a microclimate. According to Haidar, characteristics of this unseen world include a stable temperature of slightly above 32 degrees.

Small rodents like voles and mice move freely, creating small tunnels to connect food sources with their homes. Some plants continue to grow and fungi keep decomposing organic matter.

Cape Cod isn’t typically a subnivium “hotspot,” due to our somewhat temperate winters. But many parts of New England have a solid snowpack for much of the cold season, and that insulating layer is being challenged by climate change.

According to the University of Wisconsin, “rising temperatures brought about by climate change can result in thinner snowpacks or more frequent melting and refreezing. This reduces the insulating effect of the snowpack and the temperature stability of the subnivium environment, which leads to freeze-and-thaw cycles that make it more challenging for organisms to survive.”

What about birds?

Mark Faherty, Science Coordinator at Mass Audubon’s Wellfleet Bay Wildlife Sanctuary, said a heavy snowpack can be challenging for some birds who tend to find food in leaf litter. He placed Carolina wrens in that category. “Their population can get knocked back by a very snowy winter like this, because of how much feeding they do on the ground.”

A belted kingfisher at Harwich Conservation Trust’s Robert F. Smith Cold Brook Preserve. Photo by Gerry Beetham

When asked if it was important to keep bird feeders stocked in snowy conditions, Faherty replied, “I think if the birds could comment, they’d say, yeah, keep those feeders stocked, but remember that most birds don’t ever visit bird feeders.”

Faherty said chickadees and other backyard birds don’t need feeders, but added that some studies have shown a higher winter survival rate for some birds if feeders are present.

In a place like Cape Cod, where snowy winters are intermittent, it can be easy to think that wildlife might be surprised by the appearance of a snowpack. Faherty makes the point that many species found on Cape Cod also inhabit places where winter snow is a regular thing. “Whether there’s snow or not, they are able to adapt,” he said.

And while relatively long-lived humans might have memories of many winters, with stories of heroic shoveling or years without snow, it doesn’t work that way for most animals.

“It’s not like they remember five years ago,” said Faherty. “The average small animal or bird out there is less than a year old. For them, this is what winter is like. It’s the only winter they’ve ever known.”

A good melt

Even though it seems like a heavy snowpack can last forever, we all know that it eventually melts. This slow release of water can be a real win for plants and wildlife.

Snow provides excellent opportunities to observe animal tracks, like this rabbit footprint at the Robert F. Smith Cold Brook Preserve. Photo by Gerry Beetham

According to the Society for the Protection of New Hampshire Forests, “snow stores precipitation like a sponge, preventing run-off over frozen soil. Slowly melting snow in late winter recharges ground water aquifers, re-fills vernal pools used by amphibians and releases stored precipitation to awakening plants.”

As Cape Codders slip and slide through a real winter, it seems there are reasons to savor the unexpected gift of heavy snow. Sledding and cross-country skiing conditions are the best they’ve been in years, and you can finally perfect your igloo-building skills.

And for nature lovers, it’s a great time to observe animal tracks and figure out what our outdoor friends are up to.

“I love the snow,” said Faherty. “There are all kinds of cool tracking opportunities for people. A friend of mine just tracked an otter slide over a quarter of a mile. And now we have fishers, which we didn’t have 25 years ago.”

So, pull on your boots, zip up your coat, don a goofy hat and get out there. There are adventures to be had and wildlife to observe in this winter gift world. And we can share these bold tales of derring-do when we’re sitting on the beach this summer!

Photo gallery

HCT’s ace volunteer photographer Gerry Beetham captured captured these fantastic snow images on a recent trip to the Robert F. Smith Cold Brook Preserve in the heart of Harwich Port — enjoy!

—Your tax-deductible contributions help fulfill the mission of the Harwich Conservation Trust to preserve land that protects woods, water, wildlife and our shared quality of life. And your land-saving financial support helps us preserve beautiful properties that can become stellar trail destinations. Find out how to donate by clicking here.