Part 9

The incident got the other squirrels singing again; but the confidence was gone, and soon it was quiet. What dreams do squirrels dream, I wondered, looking around. I saw that place more clearly then, having been caught between a marten and its prey. I saw each spruce: its age, its condition, the onslaughts it had borne; the beargrass coming up in an opening; and down the trail a meadow that was yellow, white, and red with sulphur plant, mariposa, and Indian paintbrush. Bees, flies, spiders, and butterflies worked that little garden tucked among the crowding trees. Countless forms of life beneath the soil and bark, in tunnel, crevice, hole, and pocket, working unseen to sustain their lives, and somehow, when all were added up, maintaining the forest as well.

A flicker called, its loud Klee-yer breaking the forest hush. Birds, mammals, plants, insects—all hide together here, their lives so skillfully embroidered that no loose thread exists that my mind might grasp to unravel and understand the work.

The forest had once been a place that obstructed my view, a great blank to stride through, a few hours of necessary blur before the high lake or pass was reached. Now I was quite content to remain awhile beneath these great-boled trees.

■ A forest, like the mountains themselves, supports various levels of life. The floor and substratum are a great processing plant where bacteria, fungi, and insects work, decomposing the plant and animal litter, recycling dead and discarded tissue back to simpler organic compounds, gases, and minerals, thereby providing sustenance for growing plants. As spiders, shrews, wrens, and thrushes seem to know, there is good hunting on the forest floor.

Just above the forest floor is the herb layer, a seasonal layer of growth including flowers, mushrooms, grasses, and other small plants.

Above that grows the shrub layer, then the understory of young trees awaiting their chance to take a place in the forest’s canopy high above. From the swaying canopy, exposed to the full force of sun and wind, to the dim, moist floor, the forest provides a wide range of habitat.

Relatively few animals live in the treetops. The almost incessant motion makes nesting too hazardous for birds. Red squirrels venture up to cut cones in the canopy, but store their booty and make their nests farther down.

In the mid-range between canopy and understory, goshawks and Cooper’s hawks nest. Woodpeckers, nuthatches, and sapsuckers forage on the tree trunks and nest in cavities they excavate or appropriate. Red squirrels and the nocturnal flying squirrels create a major traffic here, along with the martens and owls that hunt them.

The understory and shrub layers house the greatest numbers of nesting birds. Here the effects of storm and rain are minimized and protective cover is greatest. Vireos, thrushes, warblers, hummingbirds, bluebirds, flycatchers, and others can be found among the tangle of this sometimes impenetrable layer.

The most populated area, the forest floor, supports an astonishing abundance of organisms. Below the busy traffic of mice, shrews, and larger animals is a bewildering array of insects and other invertebrates. The attrition rate in the litter of the forest floor—a continual battleground difficult to comprehend—is enormous. The smaller the organism, the greater its numbers are likely to be. This humus-rich, moist soil teems with bacteria, and a handful will contain surprising numbers of small spiders, pseudo-scorpions and almost microscopic mites.

Each year some two to three thousand kilograms, dry weight, of falling material litter an average hectare of forest. All this plant and animal waste—twigs, leaves, limbs, fallen trees, feathers, hair, feces, and carcasses—is processed by the armies of decomposers that thrive on the forest floor. With the aid of larger creatures that break up the plant and animal tissue, most microscopic bacteria are able to decompose from a hundred to a thousand times their own weight every day.

Few trees die of old age in the forest. The seedling mortality rate is necessarily high, since far greater numbers of seeds germinate each year than can reach maturity. Of those that do, many fall victim to the ever-present dangers of disease, insect infestation, windfall, stream erosion, and fire. Insects alone present a formidable threat to trees, for they have evolved every means of attack—chewing and mining leaves, boring into twigs, eating cambium and heartwood, sucking sap, triggering galls. If the insect world did not police itself, aided by spiders, insectivorous birds and other animals, forests and other plantlife would quickly fade before the chewing, boring, sucking horde.

■ Through the trees the light on Citadel shows the morning slipping by. As I start to get up I see a garter snake sliding out into the dusty trail, seeking the sun-warmed earth. Moving slowly, alert for danger, it probes the air frequently with its sensitive tongue. But against the lightcolored duff its dark shape offers a fine target, begging attack. A chipmunk, watching from a nearby lookout stump, twitches its tail nervously over its back, curious—perhaps suspicious—at the sight of a snake. Very slightly the snake’s head goes up, its tongue flickering. For a few seconds reptile and rodent regard each other. Then the chipmunk drops back soundlessly into its hollow stump, and the snake lowers its head onto warm ground.

Some day soon, a sparrowhawk or weasel will interrupt the snake’s morning sun-bath. The snake will fuel bird or mammal for a time, as mice, fledgling birds, and insects now sustain the snake. The chipmunk too, rummaging nearby, lives in shadows of talon and tooth.

Until that time of sharp encounter, each has its own niche, a way of life, a shaft of sun, and food enough.

A Walk in the Redcedar Forest

Climax! The word takes on a true significance here, among these broad-based trees. When you enter this forest the road noise does not follow far—as, when you walk into a cave and turn a corner, sound and light are left behind. There is a surprising spaciousness, a feeling of openness in a mature western redcedar forest. With scant understory and the canopy so far above and everywhere complete, it seems like some vast, high-ceilinged catacomb, pillared by the huge, shaggy-barked cedars and the deeply scored trunks of the black cottonwoods. The floor is strewn with fallen giants in magnificent disarray, uplifted roots still grasping fractured rock.

A rainy day is a good time to walk a cedar trail, when the dull light seems to shine from the wet moss, making the underleaves of devil’s-club and Rocky Mountain maple glow. Wind and rain, like light, penetrate with difficulty the latticework of this canopy; thin lines of fog develop over the bogs. The air is fresh with growing plants, snow-cold still when the first spring flowers appear.

Fiddleheads of unfolding lady ferns line the trail in May, pushing up from the hub of last year’s leveled, lifeless fronds. Beds of trillium shine their white, three-pointed flowers like flashlights in the dark recesses. Unlike the small, hidden calypso orchid, which bears its purple spikes and yellow throat low above the moss, the trilliums make no secret of spring growth. They are bold, handsome plants, broad-leaved and tall, with waxy white petals that tinge to purple in their month-long bloom.

Moss covers everything. Boulders are green and weightless-looking, resilient and topped with miniature forests of cedar seedlings. Ancient fallen trees are disguised with blankets of moss, sprouting hemlock here and there. The rich greens that characterize Glacier’s summers seem to begin here amid the moisture-glossed leaves of twinflower, bunchberry and bead-lily.

Later, the spiders will spin thousands of kilometers of gossamer filament among the trees. The orb-weavers will hang their webs high and low, suspended in every opening. Walking through the forest then, you will see shafts of sunlight whirling in the higher webs until they seem like tops set spinning among the treetrunks.

Indianpipes, the “ghost flowers” that need no light to grow, will break through the forest soil. Like mushrooms, with fruiting bodies that are nourished by underground mycelia, these saprophytes absorb their nutrients from a fungus that covers their roots.

Receiving an average of about 18 centimeters more annual precipitation than forests east of the Divide, Glacier’s redcedar-hemlock community hoards its moisture. Its dense growth and the surrounding mountain walls inhibit the circulation of drying winds. Mosses and ferns transpire their moisture, which you can feel; place your hand close, and you will sense a coolness like the air exuding from an ice cave. Draped from the tree limbs are long filaments of squawhair and goatsbeard, black and grey lichen strands that flourish in the damp air.

Except for the black bear, few large animals inhabit the deep forest. Grizzlies find better forage in meadows or along the forest edge. Since shade discourages shrubby undergrowth, deer and wapiti will search elsewhere for browse. In summer, wapiti, grizzlies, and mule deer bucks tend to wander up into high meadows.

Contrasted to the noisy, conspicuous birds of the prairie—meadowlarks and bobolinks—birds of the forest seem elusive and secretive. Although numerous, the varied thrushes, Townsend’s solitaires, and Swainson’s thrushes are seldom seen; but when approached, they fly silently off and are swallowed by the forest shadow.

There seems to be serenity in a mature forest, as though the struggle for life is somehow suspended, the needs of the animals here less urgent, muffled. The towering redcedar forest seems to be no battlefield at all, but rather a monument to what Earth can do.

The Perpendicular Night

Behind Avalanche campground a trail leads back toward Lake McDonald Lodge. I decided to follow it one June evening, to experience the sensation of the deep forest changing into night. With the nearby mountain wall intercepting the sun, dusk comes early to this valley. On the prairie, night passes across the landscape in an even line, forthright as a waxing tide; you can almost feel the globe in its turning from the sun. There is reassurance in the night’s coming, its steady purple doming over the sky.