by Wade Davis
Photo by Markus Mauthe, Greenpeace
In the shadow of red cedar, along a stream colored by salmon, in a place where plants draw food from the air and small creatures living on dew never touch the forest floor, it is difficult to imagine a time when the coastal temperate rain forests of North America did not exist. These immense and mysterious forests extend in a vast arc from northern California 2,000 miles north and west to the Copper River and the Gulf of Alaska. A constellation of life unique on Earth spreads between sea and mountain peak, reaching across and defying national boundaries as myriad species envelop all
who live within their influence in an unrivaled frontier of the spirit.
It is a world anchored in the south by giant sequoias, the most massive of living beings, and coast redwoods that soar 300 feet above the fog banks of Mendocino. In the north, two trees flourish: Western hemlock, with its delicate foliage and finely furrowed bark; and Sitka spruce, most majestic of all, with blue-green needles that are salt tolerant and capable of extracting minerals and nutrients from sea spray. In between, along the silent reaches of the mid-coast of British Columbia, rise enormous stands of Douglas fir. Intermingled with hemlock and fir, growing wherever the land is moist and the rains abundant, is perhaps the most important denizen of the Pacific slope, the western red cedar, the tree that made possible the florescence of the great and ancient cultures of the coast.
To walk through these forests in the depths of winter, when the rain turns to mist and settles softly on the moss, is to step back in time. Two hundred million years ago vast coniferous forests formed a mantle across the entire planet. Then evolution took a great leap, and flowers were born, a mechanism of pollination and fertilization that changed the course of life on Earth. In the more primitive conifers, the plant must produce food for the seed with no certainty that it will be fertilized. In the flowering plants, by contrast, fertilization itself sparks the creation of the seed’s food reserves. As a result of this and other evolutionary advances, the flowering plants came to dominate Earth. Most conifers went extinct, and those that survived retreated to the margins. Today, at a conservative estimate, there are over 250,000 species of flowering plants. The conifers have been reduced to a mere 700 species. In the tropics, the hotbed of evolution, they have been almost completely displaced.
On all the Earth, there is only one region of any size and significance where conifers retain their former glory. Along the northwest coast of North America the summers are hot and dry, the winters cold and wet. In the summer there is ample light for photosynthesis but not enough water for most deciduous trees. In the winter, when both water and light are sufficient, the low temperatures cause the flowering plants to lose their leaves and become dormant. The evergreen conifers, by contrast, are able to grow throughout the long winters, and since they use water more efficiently than broad-leafed plants, they thrive during the dry summer months. The result is an ecosystem so productive that the biomass in the best sites is four times as great as that of any comparable area of the tropics.
White pine, the tallest tree of the eastern deciduous forests, barely reaches 200 feet; in the coastal rain forests, thirteen species grow higher, with the redwoods reaching nearly 400 feet, taller than a twenty-five-story building. Red cedars can be 20 feet or more across at the base. The trunk of a western hemlock, a miracle of biological engineering, stores thousands of gallons of water and supports branches festooned with as many as 70 million needles, all capturing the light of the sun.
The Forest Community
The real wonder of the forest lies in the astonishingly complex relationships: a pileated woodpecker living in the hollow of a snag, tiny seabirds laying their eggs among the roots of an ancient cedar, marbled murrelets nesting in the moss in the fork of a canopy tree, rufous hummingbirds returning each spring, their migrations timed to coincide with the flowering of salmonberries. In forest streams dwell frogs with tails and lungless salamanders that absorb oxygen through their skin and lay their eggs on land, in moist debris and fallen logs.
The first survey to explore systematically the forest canopy in the Carmanah Valley of Vancouver Island yielded 15,000 species, including 500 species previously unknown to science. On the forest floor, there are 12 species of slugs, slimy herbivores that in some areas account for as much as 70 per cent of the animal biomass. A square metre of soil may support 2,000 earthworms, 40,000 insects, 120,000 mites, 120,000,000 nematodes, and millions of protozoa and bacteria, all alive, moving through the earth, feeding, digesting, reproducing, and dying.
None of these creatures, of course, lives in isolation. In nature, no event stands alone. Every biological process leads to the unfolding of other possibilities for life. Tracking these strands through an ecosystem is as complex as untangling the distant threads of memory from a myth. Only within the last decade or two have biologists begun to understand and chart the dynamic forces and complex ecological relationships that allow these magnificent forests to exist.
One begins with wind and rain, the open expanse of the Pacific, and the steep escarpment of mountains that makes possible the constant cycling of water between land and sea. Autumn rains last until spring, and months pass without a sign of the sun. Sometimes the rain falls as mist, and moisture is raked from the air by the canopy of the forest. At other times the storms are torrential.
The rains draw nutrients from the soil, carrying vital food into rivers and streams that fall away to the sea and support the greatest coastal marine diversity on Earth. In the estuaries and tidal flats of British Columbia, in shallows that merge with the wetlands, live 600 types of seaweed and 70 species of sea stars. Offshore, vast underwater kelp forests shelter hundreds of species, which in turn support a food chain that reaches into the sky to nourish dozens of seabird species.
The land provides for life in the sea, but the sea in turn nurtures the land. Birds deposit excrement in the moss, yielding tons of nitrogen and phosphorus. Salmon return by the millions to their native streams, providing food for eagles and ravens, grizzly and black bears, killer whales, and more than twenty other mammals. Their journey complete, the sockeye, coho, chinooks, chums and pinks drift downstream in death, absorbed back into the nutrient cycle of life. There is no separation between forest and ocean. Every living thing on the rain coast ultimately responds to the same ecological rhythm. All are interdependent.
When a Tree Falls
The plants that dwell on land face particular challenges, especially that of securing nutrients from thin soils leached by rain. The tangle of ecological adaptations that has evolved in response is nothing short of miraculous. As much as a fifth of the biomass in the foliage of an old-growth Douglas fir, for example, is an epiphytic lichen, Lobaria oregana, which fixes nitrogen directly from the air and passes it into the ecosystem. The needles of Sitka spruce absorb phosphorus, calcium, and magnesium, releasing moisture to the canopy, allowing the lichens to flourish.
On the forest floor mats of sphagnum and other mosses filter rainwater and protect the mycelia of one of the richest mushroom floras on Earth. Mycelia are the vegetative phase of a fungus, small hair-like filaments that spread through the organic layer at the surface of the soil, absorbing food and precipitating decay. A mushroom is the fruiting structure, the reproductive body. As the mycelia grow, they encounter tree roots, and if the species combination is right, a remarkable biological event unfolds. The tree provides the fungus with sugars created from sunlight. The mycelia in turn enhance the tree’s ability to absorb nutrients and water from the soil. Without this union, no tree could thrive. Western hemlocks are so dependent on mycorrhizal fungi that their roots barely pierce the surface of the earth.
The story only gets better. All life requires nitrogen for the creation of proteins, but nitrates are virtually absent from the acidic, leached soils of the rain forest. However, fungus and tree together form mycorrhizae, which contain not only nitrogen-fixing bacteria that produce this vital raw material but also a yeast culture that promotes the growth of both the bacteria and fungus. The roots of a single Douglas fir may have as many as forty different types of mycorrhizae. Like any life form, the fungus must compete, reproduce, and find a means to disperse its spore. The fruiting body in many cases is an underground mushroom or a truffle. It emits a pungent odor that seeps through the soil to attract rodents, flying squirrels, and red backed voles, delicate creatures that live exclusively on a refined diet of truffles. As the voles move about the forest, they scatter droppings that contain yeast culture, fungal spores, and nitrogen-fixing bacteria, all that is required to inoculate roots and prompt the creation of new mycorrhizae.
In old-growth forests 20 per cent of the biomass – as much as 600 tonnes per hectare – is retained in fallen debris and snags. There is as much nutrition on the ground as there is within it. The moss on the forest floor is so dense that virtually all seedlings sprout from the surface of rotting stumps and logs.
When a tree falls in the forest, fungi and a multitude of insects attack the wood for a solid diet of carbohydrates. To secure proteins and other nutrients, the fungi deploy natural antibiotics to kill nitrogen-fixing bacteria and emit chemical attractants that draw in other prey, such as nematode worms, which the fungi dispatch with exploding poison sacs and an astonishing arsenal of microscopic weapons. Organic debris may persist for centuries. Dead trees are the life of the forest, but their potential is realized only slowly and with great patience. An inch of soil may take a thousand years to accumulate.
At the Edge of the Clearcut
The generation of this immense natural wealth is made possible by a vast array of biological interactions so complex and sophisticated as to suggest an evolutionary lineage drifting back to the dawn of time. Yet all evidence indicates that these forests emerged only within the last few thousand years.
Twenty thousand years ago, a glacial sheet more than 6,000 feet deep covered the interior of BC, forging mountains and grinding away valleys. On the coast, giant tongues of ice carved deep fjords beneath the sea. Sea levels fell by 300 feet, and the sheer weight of ice depressed the shoreline to some 750 feet below its current level. Fourteen thousand years ago the ice began to melt, the glaciers retreated, and the ocean inundated coastal valleys and islands. The land, freed of the weight of eons, literally sprang up. Within a mere thousand years, the water drained back into the sea, and the coastline became established more or less as it is today.
At first the land was dry and cold, an open landscape of aspen and lodgepole pine. Around ten thousand years ago, as the first humans appeared on the coast, the air became more moist and Douglas fir began to displace the pine. Sitka spruce flourished. Gradually the climate became warmer, with long seasons without frost. Endless banks of clouds sheltered the trees from the radiant sun. Western hemlock and red cedar worked their way north at the expense of fir and Sitka spruce.
These forests are as rare and endangered as any natural feature on the face of the Earth, as biologically significant as any terrestrial ecosystem that has ever existed. If, knowing this, we allow them to be cut down, what will it say about us as a people? What will be the legacy of our times? At the moment, less than six percent has been protected; the remainder is slated to be logged.
In Oregon and Washington only 10 per cent of the original coastal rain forest remains. In California only 4 per cent of the redwoods have been set aside. In British Columbia, roughly 60 per cent has been logged, largely since 1950. At current rates of harvest, about 1.5 square miles of old growth per day, the next twenty years will see the destruction of every unprotected valley of ancient rain forest in the province.
In an increasingly complex and fragmented world, we need these ancient forests, alive and intact. We live at the edge of the clearcut; our hands will determine the fate of these forests. If we do nothing, they will be lost within our lifetimes. If we preserve these ancient forests, they will stand for all generations and for all time as symbols of the geography of hope. They are called old growth not because they are frail but because they shelter all of our history and embrace all of our dreams.
***
Wade Davis is a native of BC, who has worked as a park ranger, forest engineer, hunting guide and ethnographer, as well as a career in film and publishing. His books include The Serpent and the Rainbow (1986), One River (1996), and The Wayfinders: Why Ancient Wisdom Matters in the Modern World (2009).
From Shadows in the Sun, Island Press, 1998, reissued 2010; revised excerpt published here by permission of Wade Davis.
