The Seasonal Shift of All Life on Earth

It is snowing in Woodstock today. April snow. The kind that falls soft and heavy onto buds that were just beginning to open, that dusts the muddy paths and the early snowdrops. And yet, beneath the patches of lingering snow, spring is already happening.

This is one of the most extraordinary things about life on this planet: it does not wait for permission. It does not require perfect conditions. It responds to signals — to light, to temperature, to the length of a day — and it shifts accordingly, often invisibly, weeks before we see any outward evidence of change.

Spring is not an event. It is a process that has already begun inside every living thing around you.

In honor of Earth Month, I want to take a step back from individual wellness practices and think about something larger: the fact that we are biological creatures embedded in a seasonal system, and that every plant, animal, fungus, and microbe around us is responding to the same cues we are… just in ways we rarely stop to notice.

When we understand this, something shifts. We stop feeling separate from nature and start recognizing ourselves as part of it. And that recognition, I've found, is where the most meaningful changes in how we live tend to begin.

The Language of Light

Every seasonal shift begins with the same signal: light. Specifically, the length of the day, what biologists call the photoperiod. As the days grow longer after the winter solstice, photoreceptors in plants, animals, and even microbes begin registering the change. This is not a metaphor. It is biochemistry.

In plants, increasing light triggers the production of gibberellins, hormones that initiate cell elongation and flowering. In many mammals, longer days suppress melatonin production and activate reproductive hormones. In migratory birds, the same light cues trigger hyperphagia, a surge in appetite that allows them to double their body weight before a journey of thousands of miles.

Even the soil changes. As temperatures rise just slightly and light penetrates the earth's surface for longer each day, the microbial communities living there, the bacteria, fungi, and archaea that form the living matrix of healthy soil, begin to stir. Enzymatic activity increases. Nutrient cycling accelerates. The mycorrhizal networks connecting plant roots begin conducting more actively.

The ground beneath an April snowstorm is not dormant. It is waking up.

What the Plants Know

Many plants require a period of sustained cold, a process called vernalization, before they can flower. Winter is not an interruption; it is a requirement. The cold literally reprograms gene expression, silencing certain growth genes and priming others. When warmth and light return, the plant "remembers" that winter occurred and knows it is time to bloom. The crocus pushing through your snow is not defying winter. It needed winter to become itself.

There is something deeply instructive in vernalization. We tend to think of winter, a more dormant or inactive season of our lives, as an obstacle to growth. But many plants cannot flower without them. The cold is not the opposite of flourishing. It is part of the preparation for it.

Maple trees offer another window into this transition. The sap run, that short, magical window when sugar maple sap flows freely, happens precisely in the overlap between freezing nights and thawing days. The pressure differential created by this temperature oscillation pushes sap upward through the tree. It requires both cold and warmth, in alternation, to work. Neither alone is sufficient.

The forest itself is a different organism in spring than it is in winter. Deciduous trees, still bare, allow light to reach the forest floor. This brief window before the leaf canopy closes is when spring ephemerals bloom: trout lilies, trillium, and bloodroot. They complete their entire above-ground life cycle in weeks, before the trees above them shade them out. They have evolved to live precisely in the gap, in the transition.

Life does not just adapt to seasons. It has organized itself around them.

What the Animals Know

Black bears emerging from their winter dens in Vermont in April are undergoing a profound metabolic transition. During hibernation, their heart rate dropped to as low as eight beats per minute, their body temperature fell, and their fat stores fueled months of physiological maintenance without food or water. Emerging, they enter a phase called walking hibernation. Their bodies are slowly reactivating digestive function, their gut microbiome shifting in composition as their diet changes from nothing to the first green shoots of spring.

The timing of emergence is not random. It is cued by temperature, light, and barometric pressure; an integration of environmental signals that tells the animal's body when conditions are safe enough, and food available enough, to return to full metabolic activity.

Songbirds returning to Vermont are navigating by the stars, by magnetic fields, by memory. Woodcocks, among the first spring migrants here, perform their aerial courtship displays in open meadows at dusk, a behavior driven by the same photoperiod signals that trigger flowering in the surrounding plants. The meadow and the bird are responding to the same cue, in synchrony, for reasons that have been evolving together for millions of years.

Even insects, which most of us barely register, are orchestrating a precise seasonal emergence. Pollinators have co-evolved with their host plants so precisely that the timing of their emergence often aligns with the plants' flowering within days. Disrupt the seasonality through habitat loss, temperature shifts, or artificial light, and these relationships can fall out of synchrony. Ecologists call this "phenological mismatch," and it is one of the more quietly urgent stories of our ecological moment.

Synchrony, in the natural world, is not incidental. It is the thing itself.

What We Know (And Often Forget)

We are not exempt from seasonal biology. We are mammals. We have circadian rhythms, the 24-hour internal clock regulated by light. We also have circannual rhythms, annual biological cycles that shift with the seasons. These include fluctuations in melatonin, serotonin, cortisol, immune activity, gut microbiome composition, appetite, mood, and sleep architecture. The science on this has grown considerably in recent years, and it paints a clear picture: our biology is seasonal, even when our schedules are not.

Serotonin levels, the neurotransmitter most associated with mood, motivation, and social connection, are influenced by light exposure and tend to rise in spring. Melatonin production, which regulates sleep and is suppressed by light, shifts with the changing photoperiod. These are not small effects. They are measurable shifts in neurochemistry that influence how we feel, how we sleep, how we connect, and how much energy we have to move through the day.

The gut microbiome — that vast internal ecosystem we explored back in February in the context of the gut-brain-skin axis — also changes seasonally. Research on populations with greater seasonal variation in diet has shown meaningful shifts in microbial diversity and composition between seasons. When we eat more roots and preserved foods in winter and more shoots, greens, and fresh foods in spring, we are not just following preference. We are feeding different microbial communities, which in turn modulate our immune function, our inflammation levels, and our mood.

Spring appetite is real. The craving for green things, for brightness, for movement — these are physiological signals, not just psychological ones. Your biology is asking you to shift, just as the maple is shifting, just as the bear is shifting.

The Mismatch We Live In

Here is the tension most of us navigate: our environments have become largely aseasonal. Our food arrives from the other hemisphere when the local soil is frozen. Artificial light extends our days regardless of the sun. Our thermostats keep us at a constant 67 degrees. We work the same hours in December and April. We eat the same foods year-round.

This is not a condemnation. It is simply worth identifying. Because there is a cost to the mismatch between our aseasonal lives and our deeply seasonal biology. It shows up as fatigue that doesn't resolve, as mood that dips without a clear cause, as a body that feels slightly out of step with itself. Chronobiologists, scientists who study biological timing, are increasingly interested in how this mismatch contributes to metabolic disruption, immune dysregulation, and mood disorders.

We cannot and probably should not try to recreate a pre-industrial seasonal existence. But we can close the gap in small, meaningful ways. And spring, as it arrives — even slowly, even under snow — is an invitation to begin.

Coming Into Season with the World Around You

What does it actually mean to live more seasonally? I don't think it requires a dramatic overhaul. I think it starts with attention: noticing what is shifting outside and asking whether anything in your life might want to shift with it.

Here in Vermont, the signals are unmistakable even when the snow is still falling. The light is different. It stays longer. It is doing something to the maples, the woodcocks, the spring peepers, and the mycorrhizal fungi in the soil, and it is doing something to us, too, whether we acknowledge it or not.

What the natural world models for us, again and again, is that transition is not a moment. It is a process, often invisible, that happens before any outward sign appears. The spring flower has already been preparing beneath the snow. The metabolic shift is already underway before you feel it.

The snow will melt. The buds will open. The woodcocks will arrive in the meadow at dusk and spiral upward into the darkening sky, following the same impulse that has moved them for thousands of years. And we will feel something, too… a lightness, a pull toward the door, an appetite for the world that winter quieted.

That feeling is not incidental. It is ancient. It belongs to you.

Welcome to spring — finally, slowly, inevitably — here in all its snowy, mud-season, extraordinary glory.