The industry had declared war on those parts of the ecosystem—the leafy plants and broadleaf trees, the nibblers and gleaners and infesters—that were seen as competitors and parasites on cash crops but that I was discovering were necessary for healing the earth.

a web of interdependence, linked by a system of underground channels, where they perceive and connect and relate with an ancient intricacy and wisdom

We think that most important clues are large, but the world loves to remind us that they can be beautifully small.

fungal species. More than a million exist on earth, about six times the number of plant species, with only about 10 percent of fungal species identified.

loggers once stopped and carefully gauged and evaluated the character of individual trees to be cut. Transportation by flumes and rivers kept cuttings small and slow, whereas trucks and roads exploded the scale of operations.

Douglas fir and ponderosa pine were both better than the spruce and subalpine fir at minimizing water loss, helping them cope with the drought. They did this by opening their stomata for only a few hours in the morning when the dew was heavy. In these early hours, trees sucked carbon dioxide in through the open pores to make sugar, and in the process, transpired water brought up from the roots. By noon, they slammed their stomata closed, shutting down photosynthesis and transpiration for the day.

Could the old trees be helping the young ones by passing them water through root grafts? Grafts were unions where roots of different trees spliced into a single root, with phloem shared in common, like veins grown together in a healing skin graft.

Trembling aspen are unique in that many stems of the same individual spring from subterranean buds along a shared network of roots, and I wondered if the aspen copses were accessing water from the ravines and passing it upslope through their shared root systems.

the prevailing wisdom was that trees only compete with one another to survive. That’s what forestry school had taught me, and it was why my logging company liked fast-growing trees spaced well apart in rows.

A mycorrhizal fungus formed a relationship—a life-or-death liaison—with a plant. Without entering into this partnership, neither the fungus nor the plant could survive.

the fruiting bodies of this group of fungi, which gathered water and nutrients from the soil in exchange for sugars made through photosynthesis from their plant partners. A two-way exchange. A mutualism.

The mycorrhizal fungal threads grew between the cells of the plant roots, their spongy cell walls pressed against the thicker plant cell walls. The fungal cells grew in a web around each plant cell, like a hair net covering a chef’s head. The plant passed photosynthetic sugars through its cell walls to the adjacent fungal cell. The fungus needed this sugary meal to grow its network of fungal threads through the soil to pick up water and nutrients. In return, the fungus delivered these soil resources back to the plant, through the layers of pressed-together fungal and plant cell walls, in a two-way market exchange for the photosynthetic sugars.

mycorrhizal fungi helped food crops grow because the fungi could reach scarce minerals, nutrients, and water that the plants couldn’t. Adding fertilizers full of minerals and nutrients, or providing irrigation, artificially took care of things, causing the fungi to disappear.

With a little effort, we could apply a more sustainable method by encouraging the development of the highly coevolved mycorrhizal relationships. Instead, foresters ignored the mycorrhizas, or—worse—killed them with fertilizer and irrigation in the seedling nursery, and focused only on those fungi that damaged or killed big trees, the pathogens.

The mycorrhizal symbiosis was credited with the migration of ancient plants from the ocean to land about 450 to 700 million years ago. Colonization of plants with fungi enabled them to acquire sufficient nutrients from the barren, inhospitable rock to gain a toehold and survive on land. These authors were suggesting that cooperation was essential to evolution.

All but a few of the world’s plant species—such as those grown on farms that are either naturally nonmycorrhizal or are irrigated and fertilized—require the helper fungi to soak up enough water and nutrients to survive.

the arbor-shaped membrane has a huge surface area so the fungus can trade phosphorus and water with the plant for sugar. Good for helping plants in dry climates and where soils are low in phosphorus.

Lodgepole-pine cones only open when the resin holding shut the scales starts to melt.

In the absence of recurring fire, the light-loving pines would naturally die out in a hundred years, and shade-tolerant spruce would eventually dominate the canopy. The natural succession of things up here.

The herbicide wasn’t supposed to harm birds or animals, because the poison targeted the enzyme only the herbs and shrubs produced to develop protein.

the thinking was clear and simple. Get rid of the competition. Once the light, water, and nutrients were freed up by obliterating the native plants, the lucrative conifers would suck them up and grow as fast as a redwood. A zero-sum game. Winners take all.

accidently killing the mycorrhizal fungi also killed trees. Turning to the native plants for their humus, and putting the fungi in the humus back into the plantation’s soil, helped the trees.

American weed scientists in the 1980s, following in the path of the agricultural green revolution employing pesticides, fertilizers, and high-yield crop varieties, were finding that these conditions spawned the fastest-growing crops, and the British Columbia policy folks believed they could copy this to achieve the highest potential for pine growth.

The forest industry wants fast, cheap wood, and they’ve perfected growing Douglas fir in forty years instead of hundreds on the Oregon Coast Range. They’ve been doing this for years. They’re making money hand over fist spraying red alder, then adding nitrogen fertilizers.”

We should change our focus from weed-free trees in hopes of short-term growth gains and instead consider what makes the whole forest healthier over the long term.”

Are forests structured mainly by competition, or is cooperation as or even more important?

We emphasize domination and competition in the management of trees in forests. And crops in agricultural fields. And stock animals on farms. We emphasize factions instead of coalitions. In forestry, the theory of dominance is put into practice through weeding, spacing, thinning, and other methods that promote growth of the prized individuals. In agriculture, it provides the rationale for multimillion-dollar pesticide, fertilizer, and genetic programs to promote single high-yield crops instead of diverse fields.

the prevailing theory that cooperation is of lesser importance than competition in evolution and ecology.

Because of their ability to photosynthesize, the leaves were the source of chemical energy, the engines of life. The sugar—carbon rings bonded with hydrogen and oxygen—would accumulate in the cells of the leaves and the sap then load into the leaf veins like blood being pumped into arteries. From the leaves, the sugar would travel into the conducting cells of the phloem—the blanket of tissue encircling the birch trunk under the bark and forming a pathway from leaves to the root tips. Once the sweet sap was in the uppermost sieve cells of the phloem, an osmotic gradient would develop between them and adjacent phloem cells. Water taken up by the roots from the soil would travel up the xylem—the innermost vascular tissue linking roots to foliage—and be loaded into the top sieve cells of the phloem by osmosis, diluting the solution to balance the concentration with the interlinking sieve cells. The increase in pressure in the cells—turgor pressure—would force the photosynthate downward through the smooth chain of sieve cells, eventually reaching the roots. The roots, as with the aboveground parts of the tree such as buds and seeds, need energy and are sinks for this sugary burst. (While leaves are the source of photosynthate, roots are sinks.) The root cells would quickly metabolize the sugar and move some into adjacent root cells, taking water with it and relieving their turgor pressure.

As long as leaves synthesize sugars through photosynthesis, enhancing the source strength, and as long as roots keep metabolizing the transported sugars to make more root tissues, enhancing the sink strength, the sugar solution keeps moving by pressure flow down the source-sink gradient from leaves to roots.

the photosynthate was unloaded from the root tips into the mycorrhizal fungal partners, like freight unloaded off boxcars onto trucks. The fungal cells engulfing the root cells and extending from there as threads into the soil would be flooded with the sugar. Water brought up from the soil would rush into the receiving fungal cells to balance the sugar concentration with that of the neighboring fungal cells, just as it did in the leaves and phloem. The increasing pressure from the influx of water would force the sugary solution to spread through the threads of fungal cells enveloping the roots and then out through the hyphae emanating into the soil, like water flowing from a tap through a suite of conjoined hoses. Some of the sugars would fan out to help grow more hyphae through the soil, which would also help collect more water and nutrients to bring back to the roots.

I’d discover if my intuition was right—that trees are tightly attuned, shifting their behaviors according to the functioning of their community.

we’d picked up something miraculous happening between the two tree species. Something otherworldly. Like intercepting a covert conversation over the airwaves that could change the course of history.

clear-cutting was causing carbon dioxide to pulse into the atmosphere at unprecedented rates.

Paper birch and Douglas fir were trading photosynthetic carbon back and forth through the network. Even more stunning, Douglas fir received far more carbon from paper birch than it donated in return.

The sharing of energy and resources meant they were working together like a system. An intelligent system, perceptive and responsive.

shows unequivocally that considerable amounts of carbon—the energy currency of all ecosystems—can flow through the hyphae of shared fungal symbionts from tree to tree, indeed, from species to species, in a temperate forest. Because forests cover much of the land surface in the Northern Hemisphere, where they provide the main sink for atmospheric CO2, an understanding of these aspects of their carbon economy is essential.”

Our success in coevolution—our success as a productive society—is only as good as the strength of these bonds with other individuals and species. Out of the resulting adaptation and evolution emerge behaviors that help us survive, grow, and thrive.

The old and young trees were hubs and nodes, interconnected by mycorrhizal fungi in a complex pattern that fueled the regeneration of the entire forest.

If the mycorrhizal network is a facsimile of a neural network, the molecules moving among trees were like neurotransmitters. The signals between the trees could be as sharp as the electrochemical impulses between neurons, the brain chemistry that allows us to think and communicate. Is it possible that the trees are as perceptive of their neighbors as we are of our own thoughts and moods? Even more, are the social interactions between trees as influential on their shared reality as that of two people engaged in conversation?

suppression of fire had allowed many trees to reach such an old age and large size that their phloem was thick enough to support a teeming brood of larvae. The beetle outbreak had started in northwest British Columbia and spread south to Oregon, with more than 40 million hectares now dead or dying across North America. Even though the beetle and fungus had coevolved with the pines, the past few decades of fire suppression had created a vast landscape of aging pines ripe for an epic infestation. With winter temperatures no longer dropping to minus thirty degrees Celsius for long enough periods to kill the larvae feeding in the phloem, the finely tuned symbiosis among the species had ruptured. We were in an outbreak of such massive proportion that people in its midst were reeling.

Whitebark depends on Clark’s nutcrackers to disperse its seeds, whereas lodgepole needs fire to open its cones.

What the trees were conveying made sense. Over millions of years, they’d evolved for survival, built relationships with their mutualists and competitors, and they were integrated with their partners in one system. The firs had sent warning signals that the forest was in danger, and the pines had been poised, eavesdropping for clues, wired to receive the messages, ensuring the community remained whole, still a healthy place to rear their offspring.

I’d been taught in the university to take apart the ecosystem, to reduce it into its parts, to study the trees and plants and soils in isolation, so that I could look at the forest objectively. This dissection, this control and categorization and cauterization, were supposed to bring clarity, credibility, and validation to any findings. When I followed these steps of taking the system apart to look at the pieces, I was able to publish my results, and I soon learned that it was almost impossible for a study of the diversity and connectivity of a whole ecosystem to get into print.

And everything in the universe is connected—between the forests and prairies, the land and the water, the sky and the soil, the spirits and the living, the people and all other creatures.

The nitrogen in tree rings derived from salmon was distinguishable from the soil’s nitrogen because fish at sea get enriched with the heavy isotope nitrogen-15, which serves as a natural tracer of salmon abundance in the wood.

philosophy of treating the world’s creatures, its gifts, as of equal importance to us. This begins by recognizing that trees and plants have agency. They perceive, relate, and communicate; they exercise various behaviors. They cooperate, make decisions, learn, and remember—qualities we normally ascribe to sentience, wisdom, intelligence. By noting how trees, animals, and even fungi—any and all nonhuman species—have this agency, we can acknowledge that they deserve as much regard as we accord ourselves. We can continue pushing our earth out of balance, with greenhouse gases accelerating each year, or we can regain balance by acknowledging that if we harm one species, one forest, one lake, this ripples through the entire complex web. Mistreatment of one species is mistreatment of all. The rest of the planet has been waiting patiently for us to figure that out.

Trees need to be near one another, to establish in receptive soil, to join together to build the ecosystem, mix with other species, relate in patterns that produce a wood-wide web, because the forest becomes resilient from this complexity. Scientists now are more willing to say that forests are complex adaptive systems, comprised of many species that adjust and learn, that include legacies such as old trees and seed banks and logs, and these parts interact in intricate dynamic networks, with information feedbacks and self-organization. Systems-level properties emerge from this that add up to more than the sum of the parts. The properties of an ecosystem breathe with health, productivity, beauty, spirit. Clean air, clean water, fertile soil. The forest is wired for healing in this way, and we can help if we follow her lead.

There is no moment too small in the world. Nothing should be lost. Everything has a purpose, and everything is in need of care. This is my creed.

We have the power to shift course. It’s our disconnectedness—and lost understanding about the amazing capacities of nature—that’s driving a lot of our despair, and plants in particular are objects of our abuse. By understanding their sentient qualities, our empathy and love for trees, plants, and forests will naturally deepen and find innovative solutions. Turning to the intelligence of nature itself is the key.

It’s up to each and every one of us. Connect with plants you can call your own.

the same worldviews that were degrading our forests were also convulsing our society, and that fixing these problems required a deep look at ourselves, our place in nature, and at what nature has to teach us.