By 1940, the fungus takes everything, all the way out to the farthest stands in southern Illinois. Four billion trees in the native range vanish into myth. Aside from a few secret pockets of resistance, the only chestnuts left are those that pioneers took far away, to states beyond the reach of the drifting spores.
The trees under attack pump out insecticides to save their lives. That much is uncontroversial. But something else in the data makes her flesh pucker: trees a little way off, untouched by the invading swarms, ramp up their own defenses when their neighbor is attacked. Something alerts them. They get wind of the disaster, and they prepare. She controls for everything she can, and the results are always the same. Only one conclusion makes any sense: The wounded trees send out alarms that other trees smell. Her maples are signaling. They’re linked together in an airborne network, sharing an immune system across acres of woodland. These brainless, stationary trunks are protecting each other.
Aspens everywhere, and it boggles her mind that not one of them has grown from seed. All through this part of the West, few aspens have done so in ten thousand years. Long ago, the climate changed, and an aspen’s seeds can no longer thrive here. But they propagate by root; they spread. There are aspen colonies up north where the ice sheets were, older than the sheets themselves. The motionless trees are migrating—immortal stands of aspen retreating before the latest two-mile-thick glaciers, then following them back north again.
And here’s the thing about an apple’s seeds: they’re unpredictable. Offspring might be anything. Staid parents generate a wild child. Sweet can go sour, or bitter turn buttery. The only way to preserve a variety’s taste is to graft a cutting onto new rootstock.
Before it dies, a Douglas-fir, half a millennium old, will send its storehouse of chemicals back down into its roots and out through its fungal partners, donating its riches to the community pool in a last will and testament. We might well call these ancient benefactors giving trees.
They can’t see that time is one spreading ring wrapped around another, outward and outward until the thinnest skin of Now depends for its being on the enormous mass of everything that has already died.
These people need dreams of technological breakthrough. Some new way to pulp poplar into paper while burning slightly fewer hydrocarbons. Some genetically altered cash crop that will build better houses and lift the world’s poor from misery. The home repair they want is just a slightly less wasteful demolition. She could tell them about a simple machine needing no fuel and little maintenance, one that steadily sequesters carbon, enriches the soil, cools the ground, scrubs the air, and scales easily to any size. A tech that copies itself and even drops food for free. A device so beautiful it’s the stuff of poems. If forests were patentable, she’d get an ovation.
The rain forest canopy is thick, and wind-borne seeds never land very far from their parent. Tachigali’s once-in-a-lifetime offspring germinate right away, in the shadow of giants who have the sun locked up. They’re doomed, unless an old tree falls. The dying mother opens a hole in the canopy, and its rotting trunk enriches the soil for new seedlings. Call it the ultimate parental sacrifice. The common name for Tachigali versicolor is the suicide tree.”