My first visit to the alpine zone in New Hampshire’s White Mountains was on Mount Washington. I was 15 years old, surviving day three of a high school orientation camping trip. The challenge of climbing several thousand feet to stand atop an iconic peak filled me with a sense of accomplishment. While the summit view was nice, the hot water inside the visitor center was nicer. Unlike most alpine summits, Mount Washington has a cafeteria, a weather observatory, a train, and several other buildings, a big draw for a teenager after a couple of nights in lean-tos. I never noticed the flora.
Ten years later, when I climbed Mount Washington a second time, I looked around more—not just at the view from the top, but at the forest on the trail up. The way the species of trees changed and shrank with elevation caught my attention. I noticed different wildflowers at different elevations and began to appreciate the rare alpine vegetation above treeline. These were plants tough enough to survive wild weather and an abbreviated growing season yet so fragile one errant footstep could kill them.
After dozens more trips above treeline, not only to the top of Mount Washington, but to summits throughout the Adirondacks, Green Mountains, and White Mountains, terms like “ecozone,” “boreal,” and “krummholz” became part of my outdoor vernacular, tossed as casually into conversations on the trail as the weather forecast or the distance to the next trail junction.
By age 50-something, after researching and writing several hiking guidebooks and countless articles on hiking and backpacking, I fancied myself an expert on climate as it relates to elevation gain. But a recent trek from Crawford Notch (1,900 feet) to the top of Mount Pierce (4,312 feet) with AMC Senior Naturalist Nancy Ritger proved an education in the ecozones of the White Mountains.
The affable, knowledgeable Ritger started working for AMC 25 years ago in the kitchen at the Pinkham Notch Visitor Center before moving into outdoor education. She has not only hiked an extensive portion of AMC’s trail system (she lives in Harts Location, N.H., at the base of the Davis Path) but has also become one of AMC’s top naturalists. Largely self-taught, she exudes a confidence in the outdoors that comes from her two and a half decades leading trips into the White Mountains and visiting the huts to teach people about flora, fauna, and other aspects of local ecosystems.
“The zone is not only determined by elevation but also by moisture, wind, and soil,” Ritger said as we started up the Crawford Path. “In the White Mountains, there’s more moisture the higher you climb; however, the soil gets more acidic and contains fewer nutrients as you gain elevation because the moisture washes the nutrients down the mountain.”
Her comment surprised me. I had always thought it was drier up higher, mostly because I felt drier. The wind and cooler air tugged more moisture from my body as I climbed, which it does to plants as well. But it turns out that, in the alpine zone, what species of plants are present is more strongly correlated to the amount of cloud cover and wind than the length of growing season—and clouds shroud Mount Washington and its closest neighboring peaks 60 percent of the year. It’s not only one of the windiest but also one of the cloudiest places on Earth.
By no coincidence, the Presidential Range accounts for more than half of the 13 square miles of alpine tundra in the northeastern United States. The cloud cover is a key source of moisture for the plants, as the soil is too shallow to hold much water. The plants hug the ground rather than growing tall as an adaption to the icy winter weather and wind.
Ritger’s and my destination, the summit of Mount Pierce, is the southern-most alpine zone in the Presidential Range, about 5.5 miles southwest of Mount Washington. The purpose of our hike together was to look at cues along the trail signaling the change from one ecozone, or sub-zone, to another.
Mixed Northern Forest
We entered the woods at the trailhead for the historic Crawford Path, across Route 302 from AMC’s Highland Center. A mixture of hardwoods, particularly beech trees, and a smattering of conifers, including hemlock trees, filled the forest around us. Following three rainy days, the cobbled path resembled a shallow stream. I pictured nutrients washing down New Hampshire’s mountainsides.
Lower Boreal Zone
The beech and hemlock disappeared just over a half-mile from the trailhead, near the short spur to Gibbs Falls. “We’re entering the lower boreal zone,” observed Ritger, who, like many naturalists, considers the boreal zone to have three sub-zones: lower, middle, and upper. “There are still a few deciduous trees, mainly yellow birch and paper birch, and lots of red spruce trees, but no more beech or maples.” At our current elevation, a little over 3,000 feet above sea level, the soil was poor in nutrients and the winters too long and harsh for those common broadleaf trees.
I noticed lacy, pale-green lichen clinging to many trees beside the trail. It dangled like uncombed hair below horizontal branches and appeared as scraggly fur growing from the bark on tree trunks.
“That’s old man’s beard,” Ritger said. “It’s a lichen. Lichens are actually two plants, a fungus and alga that need each other to survive. Old man’s beard is sensitive to air pollution. If the air is good, it can get quite long, but if the air is polluted, it can’t survive. It can grow from here up to the alpine zone under the right conditions.”
Judging by the multitude of whiskers in this part of the forest, the air was clean.
Middle Boreal Zone
About three-quarters of a mile past Gibbs Falls, the forest was now predominantly red spruce and balsam fir. The trees remained tall, creating a dense canopy. Bunchberry, trillium, and thick patches of moss framed the trail. We passed one fern-filled clearing and then another, then paused by a third. I took advantage of the opportunity to nibble a granola bar.
“Are we entering another zone?” I asked, prompted by the clearings, hoping we might be getting close
“Not yet,” Ritger replied. “Clearings and other airier sections of the forest are due to a singular event, such as a tree falling, which creates an opening in the canopy. It’s not a cue of a zone change.”
Ritger bent down and touched the ground next to a downed tree. She pushed a handful of spruce needles aside to reveal another layer. “As you get higher, the trees grow more slowly,” she said, letting some of the needles fall through her open fingers. “Decomposition is slower. When the water supply freezes, it slows or stops the process. Water is frozen here for long periods of time.”
I was about to reach down and touch the waxy spruce duff when two gray jays landed on a branch 2 feet from my head. I kept a close eye on them. Those sweet-looking gray and white avians are cunning thieves who would have snatched my half-eaten granola bar, given the opportunity. They eat just about anything and hoard food, too, to sustain themselves through the long winters.
“Look! A brown-capped chickadee!” Ritger exclaimed. “They’re quite uncommon. You can tell them from black-capped chickadees by their brown cap and by their call, a shorter chick-a-dee, rather than a chick-a-dee-dee-dee.”
I stuffed the rest of my granola bar into my mouth and peered deeper into the branches of the trees. Several small chickadees, half the size of the jays and each with a distinct brown patch atop its small head, flitted from branch to branch.
Upper Boreal Zone
As the diminutive chickadees hopped and fluttered farther and farther from us, we turned back to the trail and continued our climb. About 1.75 miles into our hike, the canopy bore down closer and closer above our heads. It was soon so thick at eye level I couldn’t fathom penetrating the bushy tangle.
Ritger paused by a patch of bright green moss. She told me to press on the soft mass of short, toothy stems. It felt like a damp sponge. “This is sphagnum moss,” she said. “In the first world war, soldiers used sphagnum moss as a field dressing for open wounds because it is sterile and absorbent.”
Sphagnum moss occurs in boggy areas, conifer forests, and moist tundra, sometimes in huge clumps, where the soil is acidic. Though its roots are shallow, it grows so densely that it can float atop water and even support the weight of a large animal.
Shortly after my tutorial on sphagnum moss and about 2 miles into our hike, I noticed the trees were growing more outward than upward. The few gnarled branches that poked into the air were bare on their western sides, the needles finding what little shelter they could on the leeward side of each twisted protrusion. A quarter-mile later, we passed a familiar sign announcing the beginning of the alpine zone, although the trees, mainly black spruce, were still head-high.
“Why are these signs announcing the alpine zone always slightly below the alpine zone?” I asked. “Doesn’t the alpine zone start at treeline?”
“Not necessarily,” Ritger replied. “When the trees no longer grow head-high we are at treeline. On the western side of the Presidentials, treeline is slightly lower in elevation due to prevailing winds that can carry abrasive and damaging ice particles.” Close to the ground, however, the microclimate is significantly less windy.
A few steps later, the krummholz disappeared, and a stiff breeze kicked up. Now we had definitely entered the alpine zone.
The plants in New Hampshire’s alpine zone are true tundra flora, similar to the plants in the Arctic Circle. They grow close to the ground to cope with the extreme weather conditions above treeline. Many are evergreen, an energy-saving adaptation, as they don’t have to regrow leaves each summer. Some have stiff, waxy leaves to help retain moisture, and many are rare or endangered both because they have such limited territory in which to live and because they face such harsh growing conditions. For example, Robbins’ cinquefoil is found only above treeline in the White Mountains—and nowhere else on Earth. Diapensia, mountain sandwort, alpine blueberries and cranberries, alpine goldenrod, and mountain avens are among the few plant species that survive above 4,400 feet. Some subalpine plants, such as Labrador tea and bog laurel, also grow in sheltered places above treeline, where the soil is moss covered.
As we reached the summit of Mount Pierce, we carefully stepped from rock to rock, avoiding the variety of ground covers that shuddered and shimmied in the gusty wind.
“Bigelow’s sedge, right?” I asked Ritger, pointing to a grasslike plant that grew alongside the stony route. “Aren’t all the grasses in the alpine zone really rare sedges?”
“Grasses can grow in the alpine zone,” Ritger said. “So can rushes. There’s a saying: ‘Sedges have edges, rushes are round, and grasses have joints.'”
I knelt on the rocks to get a closer view of the plant. There was no edge, and there was definitely a joint about two-thirds up its 6-inch stalk. It was an alpine grass.
I stood up again, looking across the collage of diapensia and mountain cranberries that filled in spaces around the exposed rock and tufts of alpine grass. The summit of Mount Washington appeared briefly amid the great billowing clouds. Recalling my first visit to the alpine zone 38 years ago, I realized I had learned as much in the 3.2 miles from Crawford Notch with Ritger as I had during a lifetime of hiking—corrected a few misconceptions too. More importantly, our hike reinforced my appreciation of the variety of plants the White Mountains support, in the alpine zone, as well as in every ecozone, from base to summit.
1. Mixed Northern Forest: Sea level to 3,000 feet.
What to expect: A mix of temperate hardwoods, including maple, beech, and yellow birch, as well as hobblebush and wild raspberry bushes. Fertile, well-drained soil. Shallow slopes. Many different birds, including wild turkey, barred owl, American robin, ruffed grouse, American goldfinch, and various grosbeaks.
2. Boreal: 3,000 to 4,000 feet.
What to expect: Mainly conifers, such as spruce and fir, with paper birch in the lower to midrange of this ecozone. Few bushes. Bunchberry, wood sorrel, and other wildflowers, mosses, and ferns are the dominant ground cover. Tree lichens are also common. Birds include Bicknell’s thrush, spruce grouse, blackpoll warbler, gray jay, and boreal owl.
3. Krummholz: 4,000 to 4,400 feet depending on the exposure to wind and harsh weather.
What to expect: Only conifers, typically misshapen fir and black spruce. Subalpine plants, such as Labrador tea and blueberries. Birds include dark-eyed junco, white-throated sparrow, blackpoll warbler, and Bicknell’s thrush. Some naturalists consider krummholz part of the alpine zone and/or split the boreal zone into three parts: lower, middle, and upper.
4. Alpine: Above 4,400 feet.
What to expect: No trees. Ground covers shared with the Arctic Circle, including mountain cranberries, diapensia, mountain sandwort, various alpine sedges, grasses, and rushes. Birds include magnolia warbler, yellow-rumped warbler, slate-colored junco, and red-eyed vireo. Due to forest fires or manmade clearings, some mountains below 4,400 feet are bare of trees and support similar vegetation.