by Catherine Schmitt
Walking along the craggy spine of Whiteface Mountain in the Adirondacks, looking down at the three-toothed cinquefoil turning red in the cracks and out at the waves of stunted fir on the nearby hills, Sarah Nelson observed, “It’s kind of funny how all of the mountains feel the same.”
Nelson, who has conducted extensive research in Acadia National Park and is now director of research for the Appalachian Mountain Club, has seen a lot of summits. Though the Adirondacks arose from different geologic forces, Whiteface shares extreme weather and unique flora with Mount Mansfield, Mount Washington, Katahdin – and even the low elevation summits in Acadia.
“The mountains are also sentinels for change,” said Chris Nadeau, climate adaptation scientist at Schoodic Institute, who has been leading research on restoring summit vegetation in a warming climate. Nadeau and Nelson are part of a team studying the feasibility of establishing a network of snow monitoring stations across the Northeast.
Knowing how much snow is in the mountains is important information for protecting unique plant communities, and for those who rely on downslope water supplies for drinking water and irrigation, as well as recreation and tourism. Yet most mountains in the Northeast, including Cadillac Mountain in Acadia, lack snow monitoring – fewer than five percent of snow observations occur at high elevations. “Snow and ice help shape mountain plant environments, and contribute to many of the societal benefits provided by the alpine,” said Nadeau. “Whiteface Mountain is a special place where snow is monitored using state-of-the-art instrumentation.”
At 4,867 feet above sea level, and with a distinct treeline, Whiteface Mountain is considered an alpine environment. The word “alpine” emerged six hundred years ago to describe the Alps, a mountain range in Europe, and now refers to any and all things mountain.
The highest point in Acadia, Cadillac Mountain, is 1,527 feet above sea level. And yet it fits most of the descriptions of alpine environments in textbooks and websites:
- Cold. High elevations are cooler – according to one rule, temperature decreases 3.5° F for every thousand feet of elevation. Those who regularly hike in Acadia know to bring a jacket and a hat if they plan to hike up Sargent or Cadillac. On an average January day in winter, the top of Cadillac Mountain is seven degrees F colder than the coast. There is not a lot of water on the summits, but what is there doesn’t evaporate in winter’s cold temperatures. Water freezes as it flows downhill over the bare granite summits, creating sheets, rivers, and waterfalls of ice – beautiful, but dangerous.
- Sunlit. In summer, while the mountains are still cooler than the lowlands, they also get very hot because of exposure to the sun, which is another characteristic of the alpine. On the rocks above treeline, solar radiation is intense during the day (although temperatures drop again at night). In summer, water is more likely to evaporate and be taken up by growing plants. The ice floes of February and dripping moss of April become a distant memory in August. The top inches of lichen-crusted soil dry out, crunching under a misplaced foot.
- Windy. As a mass of land that rises higher than surrounding land, a mountain intercepts currents of air and weather systems as they move through the atmosphere. In fall, migrating hawks know that on warm, sunny days, winds will move upslope, carrying them over Cadillac Mountain.
- Patchy. On Acadia’s mountains, subtle differences in location and exposure to sun and wind, and the varied substrate left behind by glaciers, have an outsized influence on climate at a local or micro scale. Ice and frost disrupt the soil and scour gravel. Sand and dust are trapped by plants, forming islands of shrubs and miniature bogs of cottongrass and sphagnum moss.
- Home to specialized plants. All of the above conditions limit what plants can grow, and communities of plants on Acadia’s summits are not found anywhere else in the park – but they can be found in the higher mountains to the north and west.
Plant patterns define the alpine
Much of the sameness Sarah Nelson observed is due to the plants. The Maine Natural Areas Program defines alpine ecosystems as “areas above treeline, where elevation and exposure create extremely harsh conditions,” but restricts alpine to mountains above 3,500 feet, which would disqualify any summit in Acadia. But the program also states, “alpine ecosystems have low and often sparse vegetation due to the harsh environment. Certain tree species may be present, but grow only as krummholz, not erect.” Other researchers have used vegetation shorter than 16 feet to categorize alpine.
Only 2.64 % of land area (outside of Antarctica) is above the global treeline. Around the world, alpine ecosystems are threatened by warming temperatures that foster the growth of shrubs and the rise of treelines.
Though trees grow on the very tops of Acadia’s mountains, they are sparse and often stunted. Cedar and fir adopt a shrubby habit, spruce tucks down in crevices and ravines, and pitch pines cluster together for shelter. Trees are surrounded by dwarfed birches, rhodora, chokeberry, and mountain holly.
Plants tend to be perennial, regrowing from the same roots rather than starting over from seed each year. This allows alpine flora to begin photosynthesizing earlier, as soon as temperatures get just above freezing, aided by red anthocyanin pigments in their leaves that convert light to heat. Masked by green chlorophyll in summer, the red reappears at the end of the growing season (like that three-toothed cinquefoil on Whiteface). Hairs on leaves and buds help trap heat and also help prevent sunburn of delicate leaf and flower tissues. Lichen and moss are abundant.
Some of these plants also grow on islands and headlands that are similarly cold and exposed. Both are what remains of the tundra that covered the Northeast after the end of the most recent Ice Age 13,000 years ago.
As the climate warmed and the forest expanded north, cold-adapted plants became isolated from the core populations now located thousands of miles north, above the Arctic Circle. Restricted to places that remained exposed, barren, and cooler – high elevations (alpine) and the Downeast coast (arctic, subarctic, or boreal) – these fragments of tundra in the Northeast have been likened to the “sky islands” of southeastern Arizona, where lone forests grow thousands of feet above a lowland desert sea.
“Acadia’s alpine is paradoxically special,” said Nadeau. “On the one hand, the alpine vegetation in Acadia is likely more vulnerable to climate change than most other places in the Northeast. On the other hand, the individuals here might have adaptations to warm environments that could help save populations at higher elevations. That makes Acadia an exceptional place for alpine research and stewardship.”
Despite their perceived “harshness,” alpine environments have an enduring appeal to people, for recreation and inspiration. From the Adirondacks to Acadia, concern for mountain futures led to key moments in conservation and science history. Because alpine areas were not logged or farmed or otherwise drastically altered before they were protected, they can be reliable places to study atmospheric change, including shifting patterns of snowfall.
Through the Northeast Snow Survey Feasibility Study and participation in the Northeast Alpine Stewardship Gathering, we are sharing experiences and learning from others how to protect Acadia’s mountains – different, but the same.
