On beings and biomes—a year in the tundra
By Madison Grosvenor
Alaska’s tundra is a land of extremes, where life has evolved to endure harsh winters, fleeting summers, and an ever-changing landscape.
Rainbow graces rolling tundra at Izembek NWR in Cold Bay, AK. Photo by Rebecca Fabbri USFWS
The word tundra comes from the Finnish word “tunturia,” meaning barren or treeless hill. This vast, treeless biome stretches across the Arctic, shaped by permafrost, strong winds, and low temperatures. Despite its unforgiving conditions, the tundra pulses with life, changing dramatically over the course of a year.
A land of extremes (and tiny plants)
The Arctic tundra is divided into two primary zones: the low Arctic, which supports more plant and animal life due to slightly warmer conditions, and the high Arctic, where only the hardiest species can survive.
Close view of tundra featuring Cetraria lichens, Labrador Tea, cranberry leaves and clubmoss. Photo by Western Arctic National Parklands.
The biome is defined by its permanently frozen subsoil, or permafrost, which restricts plant growth and limits drainage, creating seasonal wetlands in summer. The soil is thin and nutrient-poor, covered with a patchwork of mosses, lichens, sedges, and low-growing shrubs.
Without trees that break the wind, the landscape remains open and exposed, subject to extreme temperature fluctuations. Despite these conditions, the tundra provides crucial habitat for wildlife and serves as an important carbon sink, storing vast amounts of organic material in its frozen ground.
The summer wetlands provide essential breeding grounds for migratory birds and support the tundra’s complex network of animals and plants, where each species plays a role in maintaining the balance of the fragile ecosystem.
Survival in the deep freeze
For much of the year, the tundra is locked in ice and darkness.
Temperatures can plunge below -40°F, and strong winds whip across the open expanse, making survival a challenge. The sun barely rises above the horizon, if at all, in the northernmost regions. Strong winds sweep across the barren landscape, and snow blankets the ground, insulating the permafrost below. Most animals have either migrated south or adapted to endure the bitter cold.
The Western Arctic Caribou Herd travels through and sometimes winters on the Selawik National Wildlife Refuge. Credit: Lisa Hupp/USFWS.
Caribou, well-insulated with thick fur, dig through the snow to find lichen, their primary winter food. The tundra’s cold and windswept terrain is also home to musk oxen, whose long, woolly coats protect them from the icy winds.
Arctic foxes, in their white winter coats, scavenge what they can, sometimes trailing polar bears to feed on the scraps bears leave behind.
Lemmings remain active beneath the snow in subnivean tunnels, where they continue to feed and breed, providing a crucial food source for predators like snowy owls and ermine.
Life persists because these animals are well adapted to the tundra’s toughest season.
The thaw begins
Purple mountain saxifrage in the high arctic tundra. Photo by Lisa Hupp, USFWS.
As the sun climbs higher in the sky and temperatures rise, the tundra begins to burst with change and life. Ice melts, snow recedes, and the frozen ground starts to thaw at its surface. Though permafrost remains below, the top layer of soil becomes saturated with water, forming seasonal wetlands that attract returning wildlife.
Early blooming tundra flowers, like Arctic poppies and purple saxifrage, paint the landscape.
Caribou herds begin their great migration, moving north toward calving grounds in search of fresh vegetation. Brown bears emerge from hibernation, hungry after months of dormancy. Arctic hares and foxes shed their white winter coats for darker summer fur. Wolves, who made it through winter eating caribou and other prey animals, shift their focus to raising pups.
Three eiders–one Steller’s male and a pair of spectacled–rest at the edge of a tundra pond. Photo by Peter Pearsall.
Come spring, the most striking presence on the tundra is perhaps the migratory birds that make their way home to breeding and nesting grounds. Birds travel thousands of miles from warmer climates to take advantage of the brief but abundant food supply: The tundra’s newly thawed wetlands teem with insect life.
A frenzy of life
Summer in the tundra is a time of abundance. With nearly 24-hours of daylight, plants grow rapidly, carpeting the tundra in vibrant greens, purples, and yellows. Tiny Arctic poppies, sedges, and mosses grow in the warmth, while berries ripen under the continuous sun.
An American golden plover in breeding plumage among the white and gold flowers of the Arctic tundra. Credit: Lisa Hupp/USFWS.
This is the height of the nesting season for migratory birds. The American golden-plover travels over 8,000 miles from its wintering grounds in South America to nest on the tundra’s open, mossy terrain. Shorebirds like the semipalmated sandpiper and red phalarope rely on the tundra’s wetlands to fuel up on insects and aquatic invertebrates before continuing their migration to wintering areas in South America and the Atlantic.
Waterfowl also flock to Alaska’s tundra in summer. The Pacific black brant nests in coastal wetlands and then in the fall makes its way south to Baja California, while the spectacled eider gathers in large flocks on the Arctic’s remote lagoons. Snow geese and tundra swans arrive in great numbers to raise their young on the tundra’s nutrient-rich marshes. Raptors such as the peregrine falcon and rough-legged hawk use the long daylight hours to hunt lemmings and smaller birds.
The tundra wetlands of the Arctic Refuge and Western Arctic are crucial breeding grounds for these species, providing safe nesting sites and an abundance of food.
Wetlands on the Arctic coastal plain. Photo by Lisa Hupp, USFWS
The summer warmth is met with the buzzing of mosquitoes, a crucial food source for birds and small mammals. Coastal areas see a surge of activity as polar bears, seals, and whales take advantage of ice-free waters.
Caribou cows nurse their calves, while predators such as Arctic foxes and peregrine falcons take advantage of the abundance, hunting for shrews and lemmings to sustain them through the leaner months ahead.
Heading south again
As temperatures drop and the tundra prepares for winter’s return, its inhabitants make critical preparations. Migratory birds take to the skies, gathering in large flocks and embarking on long journeys south. Caribou begin their migration back to wintering grounds, moving in massive herds across rivers and mountains. Wolves follow closely behind.
Seth Kantner writes in his book “A Thousand Trails Home: Living with Caribou” of the shifting tundra seasons. He writes of his firsthand experiences hunting, studying, and living alongside caribou in Alaska’s arctic.
The tundra shows bright fall colors next to the Ophir Creek Campground in the White Mountains National Recreation Area, Alaska. Photo by Craig McCaa.
“Overnight the beautiful burgundy tundra fades to brown. A few more days and the land is almost gray brown in its acquiescence to winter’s coming. The north wind blows relentlessly now. In the morning, ice is on the ponds, with windy blue waves lapping in narrow slits not yet frozen. Afternoon sunlight is the color of straw. Meanwhile, still coming, are the endless caribou herds, their presence making this fleeting fall bearable, all part of life here.”
Predators, including wolves and bears, take advantage of the last opportunities to hunt before food becomes scarcer. Many small mammals, like Arctic ground squirrels, enter hibernation, while others, like lemmings, continue their cycles beneath the insulating snow.
The tundra’s plants release their seeds before being buried under the first snowfall, ensuring life will return once the cycle begins again.
Tundra trouble
The tundra is one of the most vulnerable biomes on Earth. Climate change is causing permafrost to thaw, shifting vegetation patterns, and disrupting wildlife migration. Increased human activity, including oil and gas extraction, poses additional threats fragmenting habitat, polluting air and water, and accelerating permafrost melt.
Coastal erosion in the Teshekpuk Lake Special Area of the National Petroleum Reserve – Alaska in the western Arctic. Credit: Brandt Meixell, USGS
In the western Arctic, the tundra is under increasing pressure from fossil fuel activities, threatening key wildlife areas like Teshekpuk Lake, a crucial breeding ground for migratory birds and important calving area for caribou. Expanding oil infrastructure not only disrupts these ecosystems but also contributes to carbon emissions, intensifying the very climate crisis that puts the tundra at risk.
Permafrost plays a crucial role in stabilizing the tundra ecosystem, acting as a massive carbon sink. Permafrost locks in decomposed plant matter and prevents it from releasing carbon into the atmosphere, effectively trapping greenhouse gases in the soil for thousands of years. As rising temperatures cause permafrost to thaw, this stored carbon is being released, further accelerating climate change, threatening the tundra ecosystem, and creating an intensifying feedback loop. Protecting the tundra means protecting a key regulator of the Earth’s climate system.
Archaeologist believe that the Western Arctic Caribou Herd has traveled through Noatak National Preserve’s tundra for at least 10,000 years. Photo courtesy of Western Arctic National Parklands.
Protecting the tundra is vital to Alaska and Alaskan communities. Tundra remains a resilient and vital ecosystem, supporting species that have evolved to thrive there. From the caribou herds that roam its vast plains to the migratory birds that connect it to the rest of the world, the tundra is a place of remarkable life and ecological importance. Protecting this biome is not just about preserving its wildlife, it’s about maintaining a critical piece of our planet’s natural heritage and ensuring that future generations inherit a world where these landscapes and all they provide us still exist.
This is the fourth in our “Beings and biomes” series. You can find previous articles below: