By Russ Harris, reprinted with permission

If you have spent any time on the Groton Trails Network this winter, you’ve likely felt it: a bone-deep, old-fashioned New England cold. After several years of “mud seasons” disguised as winters—erratic thaws and bare, frozen ground—the sustained nearly sub-zero mornings of 2026 feel like a throwback. But while we reach for an extra layer of wool, and curse the cold and our energy bills, our local forests are doing something much more profound. They are healing.

For those of us who walk the stands of the Groton Town Forest or the corridors of the J. Harry Rich State Forest, there has been a growing sense of unease in recent years. In my view, the trees have looked tired. From the thinning needles of our iconic White Pines to the premature budding of our Sugar Maples, the “biological speed-up” caused by a warming climate has put our woodlands under immense stress. This winter, however, has provided what ecologists call a “biological reset.”

The Battle for the Border

What’s happening in Groton’s woods this winter is part of a much larger ecological contest.

Groton sits in what ecologists call a “transition zone”—a biological border zone where the northern beech-birch-maple forests meet the southern oak-hickory woods. For the last decade, this border has been shifting. As winters became milder, southern species and their associated pests began marching north, putting pressure on our traditional New England natives.

But 2026 has been a year for the “Home Team.” This sustained cold appears to have helped re-establish a home-field advantage for our northern natives, checking the northward creep of southern competitors and helping ensure that Groton remains a healthy gateway to the Great North Woods.

A Shield for the White Pine

Perhaps no tree defines the Groton horizon more than the Eastern White Pine. Lately, many of these giants have looked a little sickly, plagued by needle-drop fungi that thrive in the humid, mild winters we’ve seen recently. This year’s deep, dry freeze acts as a natural sanitizer, suppressing the fungal spores that have been choking our pines.

Furthermore, the consistent snowpack we’ve enjoyed has acted as a thermal blanket. Because White Pines have relatively shallow root systems, they are vulnerable to “root kill” when the ground freezes solid without snow. This year, the insulated soil has helped keep those roots protected, ensuring that when the spring thaw arrives, our pines will have the hydration they need to push out a vibrant, healthy flush of new blue-green needles.

The Maple’s Deep Sleep

   Our Sugar Maples have also been caught in a dangerous cycle of “false springs.” In warmer years, these trees are often tricked into waking up in February, only to have their tender buds shattered by a subsequent frost.

   The “tonic” of 2026 has been the gift of deep dormancy. By staying locked in a consistent freeze, the Maples have been able to conserve their energy reserves. This supports a more synchronized spring, where sap pressure recharges properly and the trees leaf out only when the danger of frost has truly passed—a welcome sign for local maple syrup hobbyists.

Natural Pest Control

For the Eastern Hemlocks that line our stream banks and ravines, the cold is a matter of survival. The Hemlock Woolly Adelgid, a tiny invasive insect that has devastated groves across the Northeast, has a fatal weakness: it struggles to survive sustained temperatures below about −5°F. The “Polar Vortex” snaps we’ve experienced this season have likely reduced these pest populations significantly, giving our ancient Hemlocks a much-needed window to recover and thicken their canopies.

Looking Ahead

As we move toward spring, keep an eye on the canopy during your walks. Look for the clean green of the Hemlock tips and the pliable, springy branches of the Maples. We often view a harsh winter as something to be endured, but for the 130-plus miles of trails that weave through our town, this cold has been a necessary medicine.

Next time you’re out in the biting wind, look up at the White Pines. They aren’t just surviving the winter; they are thriving because of it.