I live in a forest, and know that I am fortunate. I watch flicker and siskin in the cedars. I hear thrush and vireo in the veiled vastness. Cutthroat trout inhabit the lake, wolves howl on winter nights, and raccoons venture out with their families for my scraps. But I know the forest I live in is rare and under assault. Those cedar and fir, hemlock and spruce, could be converted to money, the great driver of this modern world.

The value of forests is an ancient tale. We may recall that humanity’s earliest stories – Ramayana, Gilgamesh, Raven and People – take place in the forest, with awe for its mysterious immensity. Raven hops from its forest home to find humans inside a clamshell on the beach. Rama enlists the forest animals to help vanquish the world’s evil. When King Gilgamesh falls a tree, the forest guardian Humbaba calls out, “Who is this that has violated my woods and cut down my cedar?”

Today, the once legendary cedar forests of Lebanon and Sumer are a desert. In Western Europe, India and China, ancient forest are largely gone, reduced to scattered remnants. Forests have protectors and champions, but Earth still loses ancient forest every year to human enterprise, and now, to the new human-mediated climate.

Almost half of Earth’s forests – the once great forests that stood on Earth eight thousand years ago, at the dawn of human agriculture – are entirely gone. However, that measure accounts only for land area – approximately six billion hectares of forest reduced to three and a half billion. Many of the remaining forests survive only as tree farms, secondary growth, skeletal forests with declining plant and animal species. These remnant forests hold considerably less of their original biomass and carbon,  in ecosystems fragmented by roads and resource development. When we account for this, we find that humanity has degraded or destroyed about 70-percent, with only 30 % left as intact forests.

The world’s remaining forests survive principally in five regions: Two boreal forests in Russia and Canada, and three tropical forests in Southeast Asia, Africa, and the Amazon basin. Meanwhile, global wood consumption is projected to double over the next 30 years. Those who turn forests into money may not notice until the forests are gone, until Raven has no home, forest creatures have no refuge, and Humbaba has nothing left to defend.

Forestry fail

Annually, we lose about 13 million hectares of forest, 10 million in the tropics alone. I am struck by the fact that the combined brainpower of humanity’s schools of forestry, doctors of forestry, doctors of forest engineering, forestry consultants, and Nobel-prize-winning resource economists have not yet figured out how to achieve a sustainable yield of forest products. On the contrary, the world’s forestry schools appear resigned to overseeing the complete destruction of the ancient forests.

This failure remains particularly disturbing since genuine sustainable forestry is practiced around the world by small communities and foresters. One such forester, the late Merv Wilkinson, a friend and mentor of mine, logged his 36-hectare (90-acre) forest on Vancouver Island in Canada for 73 years, 1938 to 2011. Wilkinson’s forest held more standing timber on the day he passed away than when he started. His formula remained staggeringly simple:

“Cut below the growth rate.”

Perhaps someone should burn that into the chalk boards of all the forestry schools.

Not long ago, certain technology-optimists believed we were going to preserve the forests by going digital, but this belief has evaporated. Today, human enterprise uses six-times the paper we used in 1960 at the dawn of the computer age. Computer technology increased the worldwide consumption of just about everything, including paper.

Pulp, paper, lumber, and agriculture companies pursue the vestige ancient forests night and day, 365-days per year. Giant agriculture companies level forests for soil that they will deplete in a decade of over-production and pesticide use for genetically engineered crops that further degrade ecosystems. These companies remove forests to grow biofuels, soybeans, and palm oil, which is used in ice cream, granola bars, and cosmetics for the world’s rich consumers. Forests disappear for ranching, industrial projects, urban sprawl, resource sprawl, and energy sprawl. But now, a new human impact has arrived. Global heating is now adding to forest loss.

Throughout human history, degraded forests became scrub brush or grassland. Humans occupied those lands, farmed, grazed cattle, and paved roads. Some former forests became depleted further to become desert. Now, with a planet quickly heating and human enterprise expanding, this process has accelerated. Each year, as Earth loses forests, we gain six million hectares of desert.

Ecological feedback

Deforestation now accounts for 10-15 percent of humankind’s greenhouse gas emissions, a major contribution to global heating impact. Reducing forest cover decreases carbon sequestration, increases local temperatures, and puts more pressure on fragile or fragmented forests. Heat and drought make forests more susceptible to insects and fire. In western Canada, as boreal forest temperatures have increased, over nine million hectares of pine forest have been decimated by beetles, which for the first time on record now swarm over the northern Rocky Mountains to attack trees on the eastern slope.

The increase in frequency and intensity of forest fires, from Australia and Indonesia, to Russia and the US, releases carbon that had remained sequestered for centuries. Forest fires now contribute about a third as much carbon to Earth’s atmosphere as the burning of fossil fuels.  Globally, forests and their soils still harbor over 650 billion tonnes of carbon, equivalent to nearly 80 years of global carbon dioxide emissions from burning fossil fuels. 

Deforestation magnifies climate change impacts in tropical forests by fragmenting the remaining forest, making it drier and more vulnerable to drought-induced fire. The more vulnerable a forest to climate change, the more vulnerable the carbon stocks are to being lost to the atmosphere. This increases the risk of runaway climate change and losses of biodiversity and ecosystem services, such as clean water and breathable air. Keeping forests intact is seen as key to maintaining their resilience to climate change impact.

Above a 2°C global temperature rise, cosidered a critical threshold, we could witness dramatic shifts in forest ecosystems, but the trajectory is not linear. This non-linear response is due to the interaction between ecological tipping points. Climatologists now recognize that when one element tips – forest die-off or methane release, for example – other critical factors can be pushed beyond their delicate balance, adding to the feedback loop.

Fragile forest ecosystems

Human enterprise has generally approached forests as if they were free stores of lumber and agricultural soil for purely human priorities. The failure of industrial forestry stems from seeing forests as a collection of trees, rather than recognizing them as complex ecosystems. Ecologist Wade Davis has documented an exhaustive survey of the Carmanah Valley forest on Vancouver Island, on Canada’s west coast, which revealed 15,000 species, including 500 species previously unknown to science, in the forest canopy alone. Davis reports that on a typical rainforest floor, each square meter of soil may host 2,000 earthworms, 40,000 insects, 120,000 mites, 120-million nematodes, and millions of protozoa and bacteria.

In an historic lecture, late ecologist Gregory Bateson pointed out that the survival unit in evolution is not a species, but rather a system of relationships among species. Such a system remains dynamic, with balances shifting within the limits of available energy and resources. Each species in a forest feeds on others, digests and recycles nutrients, and becomes food for other species.

Forest fungi, for example, play a critical role in keeping forest ecosystems healthy. All life forms require nitrogen to create proteins, but nitrates are rare in acidic and heavily leached rainforest soils. Fungi help solve this problem for the entire system of a forest. Clear-cut logging, on the other hand, can obliterate the fungal networks to such a degree that replanted tree farms may produce only stunted trees in degraded ecosystems.

A common mushroom that we see in the forest is only the fruit of the fungus, the reproductive phase. Most of the real work of forest fungi goes on in the dark, below the surface. Fungi produce mycelia in the vegetative phase, tiny filaments that spread throughout the soils, absorbing nutrients and accelerating decay. When certain mycelia encounter the right species of tree root, it draws the sugar it needs from the tree, and pays back the tree by helping the roots absorb nutrients, including nitrogen and phosphate.

Together, the fungus and root form mycorrhizae, and the tree root may also host nitrogen-fixing bacteria. In the northern rainforests of Canada, the roots of an old growth Douglas fir tree may form symbiotic relationships with as many as forty different mycorrhizae. Meanwhile, the mushroom fruit stage emits odors that attract shrews, rodents, and voles, who eat mushrooms and truffles and then carry the fungal spores throughout the forests, scattered in their waste droppings.

These fungal-tree-animal-mineral relations are typical of myriad dynamic, fragile systems that constitute a forest. Worldwide, forest loss deprives humanity and all species of vital ecosystem services. Forests provide oxygen, water filtration, air purification, soils, food, and shelter for everything that lives. For the human community, forests provide building materials, paper, medicines, fuel, and places of refuge, places of discovery, peace, solitude, education, myth, and spiritual insight. Forests, along with oceans, are also Earth’s primary climate regulator and sustainer of biodiversity.

Canadian economist Mark Anielski estimates that environmental services from Canada’s boreal forest are worth about $160 per hectare per year, $93 billion per year in Canada. Deutsche Bank economist Pavan Sukhdev has estimated that humanity is losing 2-5 trillion dollars of natural capital annually from deforestation.

So, for both ecological and economic reasons, intact primary forests require priority protection. Human civilization teeters on the brink of the greatest natural disaster in our history: runaway global heating. The real value of the world’s forests rests in their integrity as engines of biodiversity, the source for the clean air we breathe, and as climate regulators. The ancient forests are 70% gone or degraded. The remnant forests must be saved, and industrial society must harvest wood products from existing tree farms and already disturbed forests.

In the recent past, some environmentalists have celebrated deals that preserve a quarter or a third of some stand of ancient forest. There may exist some political logic in saving anything we can, but our aim, and our demands need to be more bold. To preserve the integrity of Earth’s interconnected forest ecosystems, we must preserve every remaining square centimetre of our planet’s ancient forests.

“We live at the edge of the clearcut,” as Wade Davis reminds us. We either defend the last remnants of Earth’s ancient forests, or we will lose them to the profiteers. The choice is ours.