LIFE ON TOP
Preserving the Alpine Zone
By Birch Malotky
The alpine zone feels expansive, tenuous, and other-wordly. It’s a landscape of twisted rock, stunted shrubbery, and singular views, surrounded on all sides by lush forest. Mixed hardwoods on the lower slopes wave new leaves in a sea of green, spilling down the mountainside and flooding the valleys below. Above them, spruce and fir grow in thick bands between broadleaf forest and windswept ridge. Approaching 4,900 feet, the conifers shrink, gnarl, and weave their branches and roots together. When they drop below head height, the world furls out to fill the view, canopy breaking to reveal distant summits, lush valleys, and roiling clouds.
Above this transition zone, commonly called treeline, lies the alpine zone; relict patches of habitat more akin to the Canadian Arctic tundra 600 miles north than anything on the surrounding slopes.
The winter brings heavy ice deposition, abrasive, wind-whipped snow, and gusts strong enough to prune trees. There are around two frost-free months, and in the summer, despite regular precipitation, the well-drained soil remains dry, thin, and acidic. In the Presidential Range of New Hampshire, the peaks are shrouded in clouds 60 percent of the year. All told, the alpine zone is hardly a place that makes life reliant on sunlight and moisture very easy. The plants and animals that do survive live in isolated patches on ridges and summits, cut off from other populations by the sea of forest below them.
And yet, these “islands in the sky” are as, if not more, diverse than the typical northern hardwood forest, home to dozens of rare and threatened species, each of them uniquely adapted to survive in a stunningly harsh environment. Exemplars of hardiness, these species are strictly no-frills, so they might be easy to miss most of the year. A walk along the Alpine Garden trail in June, however, might have you wonderingabout the plants that know how to put on such a show.
Each leaf is no more than half an inch long, green-brushed-rouge, fat and waxy with round edges and a blunt tip. The leaves grow in tight rosettes, cheek by jowl like emperor penguins weathering the Antarctic winter. Themselves pressed together, the rosettes form a rounded blob of vegetation coherent enough to earn this plant the common name “pincushion plant.” The “cushion” itself is no more than a few inches tall and, like a tiny thicket, is nearly impenetrable. Most of the year, Diapensia (Diapensia lapponica) keeps a low enough profile that you might never see it, so tight to the ground it might well be shrink-wrapped. Starting in early June, however, its bed of evergreen frugality erupts with delicate flowers. Each stem waves a bowl of five white petals dusted gold with pollen, stars bobbing above the dark cushions that produced them. Alongside Diapensia, tucked likewise against ground that is more rock than soil, is Lapland rosebay (Rhododendron lapponicum). In bloom, its leathery blue-green leaves are submerged beneath showy purple blossoms that sport stamens longer than their petals. A miniature rhododendron, the rosebay’s disproportionately large flowers are wonderfully aromatic, if you can get close enough to the ground to smell them. The little specks of color between them reveal alpine azalea (Kalmia procumbens). Small and brilliant, it develops tight red buds that look like jackfruit, which give way to clusters of pink, crown-like flowers perched atop succulent green foliage. Together, these three illuminate the space between fields of jagged rock and dry sedge, a study in contrasts at the turn of the season. Some of the earliest alpine plants to flower, their dramatic arrival on a windswept and rocky landscape trumpets the arrival of spring in New Hampshire’s high mountains. But these ironically titled “big three,” are more than just flash in the pan. As explorers of the alpine ourselves, we have a lot to learn from them. In fact, we might learn more than we ever thought possible, as alpine plants are simultaneously reflections of the present, histories of the past, and heralds of the future. Each one has its own story to tell, and all it takes to listen is paying attention to the beauty at our feet.
Flower as Weather Station
The Mount Washington Observatory can tell us that Mount Washington has some of the worst weather on earth. It can tell you that its summit, sometimes dipping into the jet stream, has experienced gusts up to 231 miles per hour, and that the wind frequently carries abrasive snow and scouring ice particles. It can show us pictures of rime ice coating the ground and stunted trees, and thermometers nearly quivering with cold at -34 degrees. But so can Diapensia.
Like any species battling for existence, Diapensia has honed its structure and function over millennia to match the demands of its environment, each innovation a response to clear and pressing needs. For example, it and other cushion or mat-forming plants grow short and tight to take advantage of a thin layer of air close to the ground that is always calmer and warmer than the rest of the air column. Additionally, their density and shape forces wind to flow over them, rather than blow into them. This prevents gusts from wicking away their moisture and heat, or pruning their leaves and stems.
The “big three’s” leaves are all leathery, waxy, or hairy to trap and retain moisture, evidence of how scarce water is on these upper summits. Despite an annual 84 inches of rain, the soil in the alpine is so thin and well drained, and the wind so fierce, that any precipitation is quickly lost to evaporation, wind, and gravity. Waxy coatings help shield against desiccation, like putting a lid on rice to keep it from drying out, while tiny hairs hold moisture around the leaves, reducing the amount of water lost during photosynthesis.
Sunlight and heat are as precious as water in the alpine, as can be seen from the many ways that alpine plants have adapted to take advantage of them as quickly and effectively as possible. The leaves of species like Diapensia contain high levels of anthocyanin, a reddish pigment that allows them to photosynthesize at colder temperatures and lower-light conditions than other plants. It may also protect them from harmful UV rays, and even act like anti-freeze in the coldest months. Many alpine plants are also evergreen. With an average of only 60 to 70 growing days a year, these plants don’t have time to spend leafing out in the spring. Instead, with evergreen leaves, they can begin photosynthesizing as soon as temperatures get above freezing. Even so, it may take them decades to grow the size of a footprint, and years before they are ready to flower.
In flower, they seem to abandon the lean economy of energy that characterizes the rest of their life cycle, but they must, in order to attract the few pollinators that can make it in the alpine. By growing lots of colorful flowers, the plants maximize their chances of being seen. To draw the pollinators in, the flowers are cup-shaped, trapping heat and creating invitingly warm little spaces for pollinators to enter. Mountain avens (Dryas octopetala), found only in the White Mountains and Nova Scotia, will even track the sun with its flowers to increase this warming effect. It seems like a lot of effort for marginal improvement, but like many alpine adaptations, something small can make a world of difference in the most unforgiving conditions.
Flower as Topography
Becoming the ultimate alpine survivor isn’t the only way to thrive in the high mountains, however. The hardy cushion plants like Diapensia more or less carve out a niche for themselves in the most extreme, ice-scoured, wind-battered, soil-less parts of the alpine. Other species find a niche for themselves, seeking valleys and scoops in the earth, lee sides of slopes, and deeper, moister soils.
Krummholz, the aptly named “crooked wood,” is an excellent example of plants using the landscape to their advantage. Typically classified as sub-alpine, this stunted, twisted, and interwoven spruce-fir community occurs right along treeline, representing the point at which regular damage from ice and wind make it structurally impossible to grow like a real tree. Any higher and the trees may literally be ripped off the mountain. And yet, patches of krummholz sometimes make incursions fully into the alpine, typically in sunnier, more protected valleys.
The Monticello and Bigelow lawns are equally distinctive alpine communities, tucked on the flanks of Mount Jefferson and Mount Washington, respectively. Slightly less common than the cushion-tussock communities, these sedge meadows take advantage of flat areas with a northwest aspect, where the prevailing winds may create clouds and moister conditions.
The rarest alpine community, occupying less than three hectares throughout the White Mountains, is the herbaceous snowbank community. These plants lack the evergreen leaves and woody stems of most of their alpine neighbors and often include species from lower elevations. Growing under cornices along headwalls, in gulfs and ravines, and anywhere else where snow accumulates the thickest (like the Alpine Garden), these species survive the rugged weather by hiding from all but the best of it, insulated from spring frosts by a thick blanket of snow while their neighbors freeze and thaw daily. This protection means sacrificing some of the potential growing season, but they benefit from a longer lasting source of water and the photosynthetic capacity of their lush, leafy foliage. These communities are both diverse, home to 90 vascular plant species, and variable, with no one plant dominating the others. Robbins, or dwarf, cinquefoil and Boott’s rattlesnake root are both extremely rare snowbank species that are endemic to the White Mountains, meaning they don’t grow anywhere else on earth. Alpine goldenrod, another snowbank species, is important habitat for the White Mountain Fritillary butterfly, another White Mountain endemic. Representing less than 1 percent of an ecosystem that itself comprises only .13 percent of New Hampshire’s area, these communities are precious pockets of life-dotting islands in the sky.
Flower as History
The alpine zone was not always so rare, however, nor so restricted to high, rocky peaks. Like the tundra that blankets northern Canada, these stunted trees and dwarf shrubs dominated New England for a thousand years after a warming climate forced glacial retreat. Starting 14,000 years ago, ice sheets at times a mile thick retreated northward, scouring the bedrock clear of once-rich soils, shedding huge boulders and plucking sheer faces from the lee side of granite outcroppings. In their wake, they left the land barren and rubble-strewn, inhospitable to all but the hardiest of colonizers.
The lichen came first, casting grey and green bodies over the bare rock like a crust. They extracted minerals, absorbed water, and caught debris, slowly forming a mat of soil thick enough for mosses and ferns to take hold. Over centuries, sedges, dwarf shrubs, birch, and alder followed, slowly finding purchase on a landscape that was once nothing but ice.
As the climate grew more temperate, trees entered the landscape for the first time in millennia. Poplars were first to arrive, followed by spruce, fir, jack, and red pines—all of them small and sparse at first. On the upper slopes of the White Mountains, the tundra remained.
By 10,000 years ago, the forest was growing and thickening, with oak flooding the warm lowland valleys like a storm surge from the south. The broadleaf trees were closing in, pushing spruce and fir upslope, which in turn pushed at the edges of the tundra high in the mountains.
Within a couple thousand years, maple and hemlock arrived, joined later by beech, chestnut, and hickory. Together, they enclosed New England, an unbroken canopy sprawling over the landscape, except for a handful of rugged peaks that repelled their every advance. High in the Presidentials, snow blasted and wind scoured, the tundra remained, a memory of a freshly thawed world.
Flower as Bellwether
For nearly 12,000 years, the arctic plantscape of the alpine zone has remained intact. However, its historical resilience belies its sensitivity to disturbance and change. With thin soil and slow-growth, for example, it is extremely susceptible to trampling, disturbance, and the accompanying erosion. After buried cables were installed along the Cog Railway, “creating an un-vegetated zone several meters wide,” New Hampshire Habitat Action Plan reports, “recovery of alpine vegetation has been extremely slow.”
Careless foot traffic can be equally threatening, particularly to small and isolated populations like that of Robbins’, or dwarf, cinquefoil (Potentilla robbinsiana). Ninety-five percent of the world’s population of this plant was contained within one acre, and the Crawford Path ran straight through it until the 80s. Exuberant collection and damage from hikers pushed Robbins’ cinquefoil to the brink of extinction, until a timely listing under the Endangered Species Act, transplantation by the New England Wild Flower Society (NEWFS), and a re-route of the Crawford Path saved it. The cinquefoil brought together an array of partners, from the NEWFS to the Appalachian Mountain Club, the NEWFS, White Mountain National Forest, and the U.S. Fish and Wildlife Service. In 2002, this furry-leaved plant with flowers like globs of yellow paint, was removed from the Endangered Species List, the first plant to be removed because of a successful recovery.
Unfortunately, not all threats to the alpine zone are so direct and preventable. Because they exist as small, isolated patches, and already occupy the highest available habitat in their range, scientists have deep concerns over the potential impact of climate change.
According to the Fourth National Climate Assessment, released November 2018, “by 2035 … the Northeast is projected to be more than 3.6°F (2°C) warmer on average than during the preindustrial era. This would be the largest increase in the contiguous United States and would occur as much as two decades before global average temperatures reach a similar milestone.” Milder winters, more rain, and potentially altered wind patterns are predicted to accompany this warming. For the alpine zone, these changes could result in encroachment by the subalpine forest, with a rising treeline displacing alpine vegetation higher and higher upslope until eventually it is forced off the top of the mountains and extirpated from the Northeast entirely.
Disaster may not be as imminent as it seems, however. While the summits are warming, there is evidence that the warming is occurring more slowly on the high peaks than it is at lower elevations. Also, the White Mountains’ notoriously fierce winds and heavy ice deposition could help to hold treeline at bay, as it likely did during a warming period 5,000 to 9,000 years ago. We already learned from the current distribution of plants in the alpine, that subtle but important differences in aspect, slope, exposure, and soil provide a rich mosaic of habitats for a variety of plant communities to survive. That same diversity of “micro-habitats” in the alpine may provide species with the refuge they need from warming climate and changing weather patterns. Being the largest and best-connected patch of alpine habitat in the Northeast, the Presidential Range may prove pivotal in saving these species from oncoming change.
Because of this, it’s more important than ever to give the alpine zone the care it deserves and the protection it needs. The less stressed these species are from unsafe levels of ozone—from trampling, from erosion, from pollution—the greater their capacity is for resilience. Equally, the more we understand about the unique system that the Northeastern alpine zone is, and the ways that individual species respond to warming, the greater our capacity is for resistance.
THRIVE IN THE MOUNTAINS
What Hikers can Learn from Alpine Plant Adaptations
Thick, waxy leaves: Put Vaseline on your lips, nose, and cheeks to avoid windburn and frostnip. Wear lots of insulating layers and a windbreaker to hold in heat.
Low to the ground: Crouch or lay down during powerful gusts of wind to avoid getting knocked over. On a sunny day, spread out on a rock slab to soak in its heat.
Grow in dense cushions: Huddle together with friends when you’re cold to help trap each other’s body heat.
Evergreen foliage: Pack your lunch the night before, so that as soon as it’s light out, you’re ready to hit the trail while everyone else still is messing around getting their food together.
Accessory pigments: Bring a variety of snacks, some sugars for quick fuel, proteins for muscle repair, and fats for long term energy. Plants use a range of pigments to maximize the light they can photosynthesize from.
Slow growing: Don’t try to overdo it, hike the pace and distance appropriate to your fitness and energy levels, as well how much food, water, and daylight you have.
Long lived: Follow all these tips, and you will be too!