The following appeared in the 2021 Jan/Feb issue of Adirondac Magazine
By Kevin Berend
Spend any amount of time above treeline in the High Peaks and you’re sure to notice a few things: an abundance of exposed rock, the smell of soggy alpine soils, the rustling of dwarf shrubs, or the whistled song of a white-throated sparrow. But always forefront is the primary element in the alpine zone, the air.
Whether in the clammy cold of thick fog or (if you’re lucky) the warmth of the blazing sun, an alpine summit offers total immersion. Absorbing the dome of blue sky overhead, sweeping panoramic views, and ledges and deep ravines below, all while bracing against gale-force winds. The feeling of standing in the sky.
It is no surprise, then, that global changes to our atmosphere are likely to have consequences for alpine areas. Climate change is causing increased temperatures, shifting weather patterns, and many complex and unpredictable impacts on ecosystems everywhere. The High Peaks will not be spared. In fact, alpine areas worldwide are warming at a disproportionately high rate, and the Northeast is already the fastest-warming region of the contiguous United States. Extreme weather is nothing new to New York’s alpine summits, but along with battering rain and ice, the wind now seems to bring with it a sense of looming change. Will we be ready?
My experience with alpine plants came first as a summit steward in the High Peaks, and later through studying the interaction of snowmelt and plant phenology (the timing of seasonal events such as leaf-out and flowering) on Mt. Washington, New Hampshire. Dubbed “arctic-alpine,” these sedge meadows, cushion plants, heath shrubs, krummholz, and a wide variety of mosses and lichens are holdovers from the end of the last ice age, when glacial retreat left behind tundra conditions across the Northeast. They now exist in New York State only atop the highest High Peaks, where they form a complex mosaic of habitats that provide crucial functions to the surrounding forest ecosystem. Covering some 150 acres in total, they are truly an ecological treasure.
For plants adapted to tundra conditions, though, climate change portends a precarious future. Arctic-alpine communities are particularly sensitive to changes in temperature and precipitation, and the rapid pace of change means that stress will continue to mount. While still relatively little is known about the specific ways in which climate change will affect arctic-alpine ecosystems in the Adirondacks, we do have an idea of what may be in store.
First, snowmelt and frost cycles are key to the health of arctic-alpine plant communities. An increase in average temperature, forecasted in climate models, may lead to a decrease in snowpack levels or advanced timing of snowmelt at high elevations, with potentially serious consequences for the growth, development, and reproductive success of arctic-alpine plants. Advanced snowmelt triggers plants to flower earlier, potentially before the emergence of insects adapted to pollinate them. Such an asynchrony could disrupt or impair plants’ seasonal cycles. Further effects could be seen in rare or specialized habitats such as alpine snowbeds, which form in sheltered sites where snow accumulates and lasts into the warmer months. Advanced snowmelt there could decrease available snowbed habitat, affecting species diversity and the functions those communities provide, including food and host plants for insects, shelter for birds and mammals, and (potentially) genetically unique populations of lowland plants.
Second, arctic-alpine communities persist in the High Peaks because they are adapted to the extreme conditions at high elevations that most other plants cannot survive. If increased temperatures bring ameliorated conditions, arctic-alpine species may no longer be able to compete with trees and shrubs at current treeline, and those species will creep upslope. Studies have shown that this process is already occurring, with trees and shrubs displacing forbs (non-woody plants that are not grass-like) and mosses at alpine sites from Vermont to Maine. Similar trends are expected in the High Peaks, where any upward migration of treeline will result in a loss of alpine habitat.
Third, exotic or invasive species thrive in disturbed environments, where they reproduce quickly and outcompete native species for water, nutrients, and space, sometimes radically transforming ecosystems. Increased disturbance due to climate change makes the establishment and proliferation of invasive species in arctic-alpine areas more likely, while ameliorated conditions (such as a longer growing season) make conditions more favorable once they take root. Greater foot traffic of hikers over recent years has also increased the chances that invasive species will be introduced to alpine areas and makes controlling their spread far more difficult. Invasives have already been documented in the High Peaks, most notably a patch of dandelions on the summit of Mt. Marcy (of all places!) and more than a dozen species along the Whiteface Mountain toll road. On Mt. Washington, dandelions have spread from the summit building and parking areas to nearby alpine habitats, requiring yearly eradication efforts by volunteers to keep them in check. While the Marcy population does not appear to be expanding, it is possible that other more virulent species, should they become established, could pose a significant threat to arctic-alpine communities in the High Peaks.
Last, increased temperature will almost certainly have effects on other weather factors like evaporation rates, cloud cover, and precipitation. It remains unclear, though, whether such an increase will lead to an overall increase or decrease in precipitation, or whether the ratio of rain to snow will be altered. Weather models for the mountains of the Northeast are mixed on this point, with at least one suggesting that an increase in cloud cover or fog could insulate alpine areas from warming occurring at lower elevations. Given the extreme complexity of the climate system, however, precise predictions are hard to come by and such findings simply highlight how much remains to be known.
During my time in the mountains, I felt I was witnessing many of these effects firsthand. I rode out Hurricane Irene from the Lake Colden interior outpost and, days later, navigated through mud and debris left by a newly created slide. As a summit steward, unseasonably warm days weighed on my mind as I spoke with hikers, the heat seeming out of place for that cold-adapted environment. Plants at my earliest melting research sites flowered sometimes weeks earlier than others nearby, acting according to entirely different schedules. We know these events are becoming more frequent. But can we connect the dots? Of course, we can’t singlehandedly bring down carbon emissions or isolate the High Peaks from the global problem of climate change. It is the air itself that tethers their fate to that of the world at large, after all. Maybe it’s not possible to avoid some effects, and we’ll just have to get used to that.
But we can plan and be ready. A detailed, long-term monitoring program that collects data on temperature, precipitation, plant phenology, treeline, and invasive species must be a priority for the High Peaks. Without good data, we will lack the insight necessary to anticipate and address the challenges of climate change or to successfully manage alpine areas through this new era of uncertainty.