Can Trees Save the World After We’re Gone?

It is late fall, all gleam and cold, and I’ve gone gleaning. In the Arboretum again, two shakes of the running shoes take me there, into the long pondside field where they plant the Rosaceae, which Wikipedia calls a “medium-sized family” of flowering plants—but which seems vast enough to me, encompassing not only the roses, but “apples, pears, quinces, apricots, plums, cherries, peaches, raspberries, loquats, and strawberries; almonds . . . meadowsweets, photinias, firethorns, rowans, and hawthorns.” The flush of chill has reawakened my curiosity for quinces, as well as another rosaceous fruit, the medlar. Quinces and medlars, unlike their more marketable cousins, the apple and the pear, want to mellow on the branch long after they ripen; this softening into decay breaks down the astringent tannins, increases the sugars, and renders flesh that is darkened and grotty, spiced and rich. The process is known as bletting—a word that seems evocative and medieval to me, though it was only coined in the mid-19th century.

In the field of roses, then, I slow my running to a stalk, and pace the long curving beds that are moistening toward winter. There’s a long range of Dawson’s crabapple, slender upswept branches hung with myriad fig-sized fruit that has rotted into tiny dimpled sacks. I pluck one and squeeze it into my palm; a clear liquid jets forth, which tastes of bright vinegar. Further on are cherries and crabapples of other kinds, fruit-fisted and small; a sorb tree sports berries of crimson dappled gold. I come to a bush like a sheaf of switches, whip-thin branches bound thickly together; strewn about on the mulch are droves of crumpled quinces bletted into mush. They are broken beyond redemption, however, and I’m unwilling to taste. Two of the fallen fruit seem newly ripe, however, still flaxen yellow and firm to the touch.

How we taste of trees, how we gather, how we glean. They arrive now in ranks and rows, in groves planted mechanically, sprayed and petted, traipsed in precariousness by migrant workers beating the boughs or climbing ladders to unsettle the fruit crop. We would do well to remember that in our political economy with the tree there is this originary intimacy, this reach to pluck and pull, to bite, to taste. There is always for us the gleam of a tree at the center of some garden, recalled, reimagined, promising—what?—some posture beyond ferality, some self-possessing domestication that transcends grafting knife and limb saws, that transcends discipline.

In the groves, in the vineyards, however, the fruiting trees demand our attention, call forth our labor. The Georgics, in which Virgil hymns the ways of Roman agriculture, is the Roman poet’s documentary on the tilling and sowing of fields, the pasturage of flocks, the care of honeybees, an—not last, but taking priority in my account—the cultivation and care of trees, vines, and shrubs. His concern is the cultivation of trees for fruit and nut, and he celebrates the forceful creations of the nurseryman, whose craft makes strange and fruitful hybrids:

in knotless trunks is hewn
A breach, and deep into the solid grain
A path with wedges cloven; then fruitful slips
Are set herein, and—no long time—behold!
To heaven upshot with teeming boughs, the tree
Strange leaves admires and fruitage not its own.

The poet is describing the horticultural practice of grafting, which can be used to repair damage, combine fruit-heavy boughs with hearty roots, or even to create arresting and unusual latticeworks of branches for furniture making. Typically, grafting is done using plants that are related, and Virgil’s combinations are surprising: the arbutus (or madrone) with walnut; apple boughs installed on the limbs of the plane tree. Improbable pairings.

More credibly, Virgil describes the Roman vintner’s practice of training grape vines to grow on trees, including that of the chestnut, whose strength and deep-rootedness contrast implicitly with wine’s transient pleasures:

The tree that props it, aesculus in chief,
Which how so far its summit soars toward heaven,
So deep strikes root into the vaults of hell.
It therefore neither storms, nor blasts, nor showers
Wrench from its bed; unshaken it abides,
Sees many a generation, many an age
Of men roll onward, and survives them all,
Stretching its titan arms and branches far,
Sole central pillar of a world of shade.

And yet these cultivated vines, however deep-pillared by the tree to which they’re trained, fall prey readily to the depredations of fire:

. . . for oft from careless swains
A spark hath fallen, that, ‘neath the unctuous rind
Hid thief-like first, now grips the tough tree-bole,
And mounting to the leaves on high, sends forth
A roar to heaven, then coursing through the boughs
And airy summits reigns victoriously,
Wraps all the grove in robes of fire, and gross
With pitch-black vapour heaves the murky reek
Skyward, but chiefly if a storm has swooped
Down on the forest, and a driving wind
Rolls up the conflagration. When ’tis so,
Their root-force fails them, nor, when lopped away,
Can they recover, and from the earth beneath
Spring to like verdure; thus alone survives
The bare wild olive with its bitter leaves.

It’s notable that Virgil claims that it’s the wild olive tree that is hardy enough to withstand fire, distinct in that respect from its cosseted, cultivated, domestic kin. For Romans in the era of the republic, the classicist David O. Ross points out, “nature” was that which man tilled and cultivated. Ross describes the Roman understanding of nature as nearly the opposite of our own, rooted in the cycles of agriculture, with cultivation the deepest expression and even generation of nature itself. The forces of the storm, of wind and volcano and wild animal: these were divine energies visited from beyond upon the natural realm—man and his fields, his beasts, his orchards. Ross finds the basis for this argument in the etymology of natura itself, which emerges as a word for birth and things born into the world. To the Romans, says Ross,

“Nature” is agricultural, is inconceivable without man, and is his creation: but herein lies, and lay, an obvious paradox, which is indeed a central paradox for the Georgics . . . For the Romans, I think, the storm that destroys and the pests that attack are un-natural, are forces dire and hostile . . . whereas the grain and vine are the embodiment of the natural cycles of life.

Much has intruded into our understanding of natura since Virgil’s time. In addition to hymning the stateliness and sturdiness of my front-yard oak with its titan arms and teeming boughs, for example, a latter-day Virgil could sing of qualities more modern in flavor: name it as anangiosperm and member of the dicotyledonae, an erstwhile and deprecated taxon; counted in the order Fagales, which also includes the beeches, walnuts, birches, and bayberries; describe it as a biochemical reactor producing such phenolic compounds as Grandinin/roburin E,   castalagin/vescalagin, gallic acid, monogalloyl glucose (glucogallin) and valoneic acid dilactone, monogalloyl glucose, digalloyl glucose, trigalloyl glucose, quercitrin and ellagic acid—toxic and aromatic substances that arise in response to disease, pathogen, and injury; could note that its wood, calculable in board feet, is a vast treasury of xylem, a slow-flowing collision of cellulose fibers enjambed within a matrix of lignin and shot through with tyloses, microscopic outgrowths that collapse into the vessels of disused xylem to lend structure and great strength to the wood; could chant the explosion of animal vigor within this house of many mansions, sheltering life forms from the protozoan to the passerine; call it Quercus alba in the binomial system of Linnaeus, who described it on the basis of leaves brought from North America, noting also that it’s white oak to the wise and the big tree on the corner to the neighbor kids; and sing on of who-knows-what archipelago of sweet, secret appellations among its dark menagerie. All that which moves outside our sort of why, indeed.

Like Virgil, we treat trees as objects in daily life; like Auden’s object, they seem content to keep to their own edges. Or do they? There is an old, squat maple tree in a cemetery near my house, which some years ago was struck by a backhoe or some other machine; the heartwood rotted in the scar, turning to humus, which induced the living vascular tissue above the injury to send roots into the heart of the tree itself. 

Even within itself, a tree will not to its own edges keep. And the forms trees take in connection with human lifeworlds, meanwhile, engage the full panoply of our entanglement with questions of materiality, community, and design. As objects, trees inhabit or create an uncanny space in which they seem sessile, passive, pliably responsive to human acts and needs; and yet they carry on abundant and active lives of their own, with qualities and even varieties of affect remote to our experience. In their endlessly varying ways of taking up residence in proximity to the human, trees refract the dappled light of myriad material and biologic possibilities into a vast array of quotidian human experiences. Their forms suggest ways of organizing data, institutions, and knowledge (and even knowledge about trees themselves may be found subsumed in tree-like diagrams). And with the great ages they are capable of reaching, they express something ineffable and awe-inspiring about the vigor and capacities of life on earth. The longevity, endurance, and stock-still stability of even the most familiar street trees is awesome, an instance of the sublime: for we come to trees—the old ones, anyway, which surround us, enfold us, embower us—as beginners, as newcomers to arborescent forms of life well under way.

Bound within their rings in circle upon circle reaching back to sapling seasons, trees treasure up the carbon they capture from the atmosphere, metabolizing CO2 through photosynthesis to make sugars and build wood. Tree-like plants have been doing this work for nearly four hundred million years; the thick black vein of coal encircling the planet dates from the rise of the tree as a dominant form of life on the planet. This sequestration of carbon transformed global climate long before the rise of humans, or even mammals, but we’ve only begun to pay attention to it in the last few decades. Archive, waste repository, storyteller and world-maker—add these to the ways we’ve learned to do and think the tree.

We’ve flooded our atmosphere with carbon, an element which is little more than trees in potentia, in airy solution, as-yet evanescent and imaginal, waiting to arrive. And waiting is what the trees do. Breeze-blown, deciduous or evergreen, heavy with fruit or with leaves senescent flying, the trees abide. Thoreau imagined a human world of pasture and fieldstone fence without feral apple trees; now, we’re forced to contemplate a world of trees without us. In our most desperate watches, we wonder how long it will take the trees to sequester our spent carbon credits, to pull the vagrant CO2 down into their boughs, leaves, and roots, to treasure it up again in the layers of the earth. To do this work—to slowly unfold through millennia of slow-receding warmth the full measure of their dark abundance—without us.

As an object, a life form, and a form of life, the tree was already ancient when humankind came into the world. And yet we have walked many an age in tandem with trees, following and followed in turn, from continent to continent around the globe. Trees have made human forms of life possible—and those human lifeways have opened new ways for trees in the world as well. The whole career of written history has passed during the time it has taken for a few individual trees to grow from sapling to maturity—so much human activity passing like a shadow, a mid-day blur, evanescent in the sequoia’s dappled precincts. For such a tree, the days are minutiae—moments, which pass too fast for registration. Seasons are the days of tree-time, of lives measured out on the scale of glaciers and climatic epochs. This longer, slower view of time is one we might want to adopt; for in our own way, we’ve lately discovered, we humans have taken on the capacity to act with epoch-making force on the planet’s climate. Even now, the bristlecones, like many alpine and high-country plant species, strive to climb higher and higher to escape the warming temperatures of climate change. We call this change anthropogenic, and the age that it will likely characterize, the Anthropocene. And yet I don’t think we should be so quick to attribute these effects to any fundamental nature we have as a species. Climate change is the result of specific social and economic relations in human history: how we in the West, in a lineage reaching back to Virgil with his divine powers arriving from outside of Nature, have come to perceive the value of resources, landscapes, and living things. We might do better, I think, to call this age the Occidentocene, in light of the Western ways that set it in motion.

Can a tree be feral? I return to my starting question with the sense that, in this emergent Anthropocene, ferality indeed might offer the best hope for trees, and a boost for human prospects as well. I’m back with the copse of Ailanthus in Bussey Brook Meadow, watching their lithe boles bend springily in the city breeze. A steel howl rises from beyond the trees where the Acela train slices through the neighborhood on its way out of the city; lazy motes of passenger jets high above contrast with the staccato flocks of sparrows rippling the sky into tweed. On the tangled bank of the mesa, refuse peeks out from beneath the bittersweet underbrush: a bruised shoe, a tangle of copper flashing, a torn page of roofing paper, all nestle together in the loose black soil. And the slender Ailanthus, towering above, dapple these mingled objects and the promiscuous vines with a softening light. Throughout the city, stands of Ailanthus such as this mark provisional and temporary demarcations of property; they fill the vacant lots, springing from amid the tires and wreckage of fences. They shelter the trash-pickers and the gleaners, clutch and hold the poisoned soils that would otherwise run off the salvage lots into sewers that flow into Boston Harbor. These trees treasure up their carbon in dark abundance, in compounds that compose fungible resources of elemental matter and overflowing possibility. A century ago, from the dizzy imperial heights of industrial progress, it was possible to envision the city after us returning to wild forest; today, we might do better to acknowledge that a city is a feral forest, always and already; to know that forms of life are forever branching, and that bewilderment is our natural habitat.