Just for a moment, imagine what the Northeast would look like if seas were to rise 4,000 feet higher than they are now. Northern New England would be reduced to a series of islands—an archipelago of summits. You could surf cast for striped bass from the summit of New Hampshire’s Mount Tecumseh or stroll among tidal pools on the flanks of Camels Hump in Vermont.
Yet, even without this drastic flood, these “islands” still exist. But instead of being surrounded by salt water, they rise from a sea of woodlots, hayfields, and pastures, villages, small towns, and cities.
Ecologically, the region’s high elevations are islands, providing unique habitats which, like traditional islands, are isolated from each other. These unique habitats are home to many species of plants and animals—even entire communities—that are rare in the region. Many of these species exist as so-called outlier populations, far removed from their main geographic ranges. Several appear on state and federal endangered species lists, and a few, like Bicknell’s Thrush or Dwarf Cinquefoil, are endemic—existing nowhere else in the world.
How can you tell if you’re atop one of these alpine islands? Most dramatically, there are no trees, except perhaps the occasional stunted conifer huddled in the lee of a boulder or ledge. Few plants grow taller than the cuff of an average hiking boot. The Presidential and Franconia Ranges in New Hampshire are the two largest “islands” in our local archipelago, though there are many smaller islets such as the summits of Mount Moosilauke and the Kinsmans in New Hampshire and the summits of Mansfield, Camels Hump, and Killington in Vermont.
The first person to experience this unique alpine area and leave a written record of the event was an English settler named Darby Field. In 1642, along with two Native American companions, Field reached the summit of Mt. Washington. One hundred and thirty years later, in 1772, Ira Allen climbed Mt. Mansfield and surveyed that ridgeline. For early explorers, reaching these summits without the luxury of trails must have been a daunting effort, but it also subjected them to first-hand experience of the elevational changes that occur in plant communities.
As anyone who has spent time in the mountains knows, the closer you get to the clouds, the colder and wetter it gets. With every 1,000 foot increase in elevation, there is a corresponding drop of 3 degrees Fahrenheit in average temperature and an increase of about 8 inches in average precipitation. This results in a shorter growing season with wetter, more acidic, and less fertile soils than in the lowlands. Not surprisingly, overall species diversity drops as elevation increases.
Once you reach treeline, you enter the wind-whipped world known as alpine tundra. In this fragile area, natural rock gardens consisting of dwarf shrubs (primarily heaths and willows), small patches of moss, lichen-covered rocks, clumps of sedges and rushes, and an amazing display of diminutive wildflowers form a mosaic of colors, patterns, and textures. Perennial plants, whose roots survive the winters to sprout again, are the rule in the alpine zone. Annuals—plants that complete their life cycle in one season, leaving only their seeds behind—have trouble competing in such a short growing season.
While alpine plants are hardy, most depend upon a blanket of insulating snow to protect them from winter kill. As many as 75 species of plants are restricted to the alpine zone and cannot be found growing at lower elevations unless you travel 1,000 miles north to the arctic tundra of Canada and Alaska. Indeed, nearly two-thirds of Mt. Washington’s alpine plants exist as disjunct populations, or outliers, far removed from the heart of their geographic range.
The high elevations of New York, Vermont, New Hampshire and Maine are special places, rich in biological treasures, geological history, and ecological significance. They are also attractive places, both for the plants and animals that together make up the varied ecological communities and for human visitors. Who hasn’t been inspired by the sight of a snow-swept Mt. Washington towering in the distance, or a sunset view of the Adirondacks rising beyond Lake Champlain, or the familiar silhouette of Camel’s Hump looming above a spring morning’s fog?
If you have an opportunity to visit our archipelago of summits this summer, keep an eye out for some of the unique wildflowers of our alpine tundra, such as diapensia, mountain sandwort, alpine bilberry, and moss campion. But remember to stay on the trail while you’re up there. These tenacious plants, whose island homes are buffeted by hurricane-force winds dozens of times each year, are helpless beneath the tread of even a few stray footsteps.