I first encountered the word blight when I was twelve. We were leaving for a family vacation and as we drove away from our split-level home, I watched the feathery pink flowers of the Mimosa tree on our front lawn float above the fern-like leaves that hung from slender branches. This Mimosa was my icon of summer. Two weeks later we returned to a barren tree. Blight, said someone. It was a new word, but I needed no explanation.
I did not consider tree blight in the flesh again until my second visit to the MacLeish Field Station (MFS) in Whately, Massachusetts where I had come for an afternoon of writing and reflection. I was standing in a mowed field surrounded by an electric fence, looking out across the valley over to the Holyoke Range. In eons past these mountains were as tall and jagged as the Rockies; time has worn them down to gentle bumps in the landscape. From this distance, the bare gray limbs of deciduous trees looked soft, a bit of wispy mountain peach fuzz. Biologist Paul Wetzel, a tall lanky man, with light blue eyes and some gray of his own, was planting nuts in neat rows with a group of Smith College students. Wetzel studies ecological restoration, the act of reviving damaged ecosystems or habitats. At the MFS, he is part of the American Chestnut Foundation’s effort to resurrect the American chestnut forests.
Some people call the American chestnut tree the Redwood of the east. Crowded in the forest it will reach up ten stories to the sun. With ample room, it grows rotund. Either way the diameter of its girth can be wider than the wingspan of a large man and more. A Goliath, the American chestnut dominated the landscape from southern Ontario to Mississippi through the Appalachian Mountains and the Ohio Valley, until Cryphonectria parasitica (C. parasitica), a fungal spore, killed some 4 billion trees in less than fifty years.
- parasitica is a member of the Ascomycota family, a motley crew of fungi that includes Dutch Elm disease and Oak wilt as well as morels, truffles, and the yeast in your favorite local brew. A traveler and opportunist, it seeks shelter beneath tree bark, entering through openings such as a heart carved by lover or a woodpecker’s hole. Once it is past the bark’s threshold it makes a home and raises a family. Fecund, it multiplies rapidly and kills the tree cells that are in its way. In their stead a canker of dead tissue forms and begins to spread, first long and narrow, then wide around the trunk, making a tourniquet that chokes off water rising from the roots and nutrients descending from the leaves. Within a year or more, the tree dies of thirst and starvation. All that is left are ghost stumps anchored by blight resistant roots. New shoots do rise but often perish before their first nuts set. When adolescent C. parasitica spores emerge from the canker and leave home they will hitch a ride on a bird wing, beetle foot, drop of rain, or an evening wind, off to build their own canker on another tree.
Not all chestnut varieties succumb to C. parasitica’s bullying. Chinese and Japanese varieties have developed defenses and they peaceably coexist. It is likely that one of these Asian varieties is the source of all this mess. Sometime in the late eighteenth or early nineteenth century a man imported some of these beautiful trees for his garden. I doubt he meant any harm. It was de rigueur to decorate with Asian plants. Beauty was his likely goal. How did he or any of the other gardening auteurs know that his tree would bring a fungus that would wipe out 99% of the American chestnuts before his grandchildren had their own children?
Blame may or my not have been on Chief Forester Hermann Merkel’s mind when he saw the ailing chestnut trees at the fledgling New York Zoological Park (now the Bronx Zoo) in 1904. He was worried; several trees were sick, others dying. Each one marked by a rust-colored canker spattered with orange dots. It would take two more years of loss and frustration before mycologist William Murrill from the nearby New York Botanical Garden would identify the spores in those orange spots as chestnut canker – a.k.a. chestnut blight – C. parasitica. Merkel and Murrill tried to treat the trees; they pruned dead branches and doused the bark with a heavy spray of a “Bordeaux mixture” made of lime, salt, and copper sulfate, an elixir used on tender French grapevines, but to no avail. The trees died just as they did in the forest. In 1908, Murrill predicted that “All the chestnut trees are doomed to destruction.” The spores, he said, would cruise cross-country on the wind; nothing could stop their wanderlust.
A blighted chestnut forest looks apocalyptic. Within a year, cool shades of gray replace the warm browns of healthy bark. A corps de ballet of trees, strong and erect, keel over, cracking at the waist. The ghoulish scene can make the unflappable squeamish. Such devastation with no explanation was hard on people and ambiguity fuels greed in the human psyche. When threatened by loss we often respond by taking more than we need, erring on the side of destruction. Think of how we over-fish and farm. The examples of waste are legion. In the end, human uncertainty was the American chestnut tree’s undoing.
As C. paracitica spread, scientists debated. They knew that a year after a tree died, the wood was still good for utility poles, a commodity that brought a hefty price. Owners had nearly ten years to sell a tree for lumber. Nevertheless, experts worried about the spread of blight, fires, and the prospect of financial ruin. One Director of the U.S. Forest Service in Appalachia told lumbermen: “The best thing to be done is chop down the good remaining chestnut trees and permit nature to grow other kinds of trees in their places.” We know now that we blundered when we eradicated most of the vigorous chestnuts. They might have lived to pass on blight resistant genes.
The demise of the American chestnut tree was a shock; chestnut wood cradled newborns and gave shelter below ground when corporeal life was over. Its strong, tannin rich, rot resistant, straight grained timbers were built into our days, from floorboards to telephone poles. Then there were its sweet nuts, each bite containing more sugar than an apple. Some called them mast, others heaven. In summer spiny green balls hung about the tree’s limbs, waiting until autumn’s cold gave them leave. Inside three deep brown nuts – the shade of a chestnut mare or chestnut hair – grew in a velvet womb. They were round and small, two with one flat side pancaking both cheeks of the middle nut. When the burrs fell and burst open, yielding their treasure, wild turkeys, white tailed deer, black bears, and before they too were gone, passenger pigeons, rejoiced. Hogs reveled in their flavor. In Appalachia farmers would set their pigs loose in the forest to forage. No worries about who owned what tree. There was enough mast for all, and leftover for people too. One tree could produce three bushels. Imagine a whole forest full. In the mountain towns of Appalachia cash for chestnuts paid debts, bought shoes, sugar and salt, anything that could not be made at home. Appalachian women were known to say that a grove of chestnuts is a better provider than a man. Easier to have around as well.
Hogs and chestnuts were two of the four staple crops that supported the Appalachian subsistence farmer. The others were moonshine and apples. When the chestnuts trees died, the hogs had to go, and then there was no money to buy moonshine. The children left for more prosperous cities, though life there was hard, too, as the blight hit during the depression. Still, there was greater opportunity than in the dying landscape they had once called home. Families separated, men lost their jobs, and women suffered from yet another betrayal.
That I never heard of the chestnut blight astounds me. I grew up in a family focused on world affairs, science, and the arts. New York City, where the blight was discovered a century ago, was only a brief commuter train ride away. Yet the American chestnut blight was nowhere in my imagination. Why? Perhaps my family’s history of Eastern European immigration, so typical of the time, was at play. Grandparents and great grandparents arrived by boat, entered the concrete plains of New York City, and never left. They came in time to see the New York chestnut trees die, the earliest victims of the epidemic, but they cut diamonds, served alcohol and hauled milk to the local jail – trees and their lumber were not part of my family’s stock in trade. Perhaps these distant relatives, some of whom fled pogroms whose violence often emerged from the forest, had other reasons to ignore the tree’s plight.
Paul Wetzel has a nimble mind that flexes between botany, statistics, evolutionary biology, policy, and ecology. In his professional life he has measured the impact of ozone on Red Spruce, designed noise barriers for highways, counted wild life, written environmental impact statements, built machines that measure the weather, and he continues to help restore the Everglades. At the MFS he spends some of his day tending to the needs of the chestnut orchard that will someday yield blight resistant trees – hopefully. The work requires patience and a tolerance for ambiguity. “When you plant a nut,” says Wetzel, “you have to have faith because you don’t see anything for three weeks.” Chestnut seeds drop taproots down a foot before they risk sending a tender stem up into the world.
On my way to the orchard I stopped to warm my face in the sun. It was another seventy degree, bare, blue sky day – no hint of a cloud anywhere. The voices of young women, yards away, mingled with the sound of gasoline-powered machinery off in the distance. Even when surrounded by over 240 acres you can only be so remote in this part of the world.
Wetzel was digging holes with a narrow spade in the orchard. Three female students filled the voids with new seedlings to replace the ones that had died. The students are the reason this orchard exists. Wetzel suggested chestnut restoration to his colleague when they were looking for field station projects that would engage young minds. Many students who come to Smith College are interested in conservation, but class, labs, sports, and clubs make it difficult to find time for the twenty plus-minute trek to the field station, so he designed a program that allows students to join the restoration effort in whatever way they can. They dig, weed, plant, and return to find spindly seedlings. That is good enough for Wetzel, who takes a long view on education. They have gotten outside, cared for something, and learned a little bit more about conservation. “It gives me an internal smile,” says Wetzel, “deep down I’m inspired – they are interested in doing this.”
The nuts settling down in the orchard will become American chestnut trees with a twist. Each one is bred with a smidgeon of Chinese chestnut, a variety immune to chestnut blight. This was the first round of planting; 360 nuts and seedlings representing three genetic families, or lines, from three different American “mother trees.” In time, there will be 3000 trees on this acre plot with twenty different mothers. Every seed the progeny of a series of genetic commingling, six crosses leading to the holy grail – a tree with the tall grace and sweet nuts of the American chestnut and blight resistance of the Chinese tree – 94% American and 6% Chinese. When the 3000 Restoration chestnut saplings are infected with C. parasitica, all but about twenty will die. The survivors will sire a new generation of trees, offspring that might prove resistant to the blight that killed their ancestors.
There is something startling about raising trees to kill them, even in the name of restoration. This is illogical – I know. My whole world is made of wood, from the pencil in my hand, to the timbers that hold up my roof, solar panels and all. Yet there was something in that field of white tubes, collars meant to protect the saplings when they were tender babes that made my heart sink. Images of Arlington Cemetery came to mind, with its repeating pattern of white headstones, all straight edged and rounded on the top, soldiers, some long gone, others recent; boys who were once breast fed and held through night terrors and spiking fevers, buried beneath the polished rock.
Sometimes we kill 2,980 trees to find the twenty sturdy ones. Those that proffer hope for a future that would bring back the glories of the past. It is said that when the chestnut trees bloomed in July the forest would shimmer, and when their white flower petals dropped it was like summer snow. I would like to see this show just as I would love a spoonful of chestnut honey, ambrosia that is supposed to be like no other taste of honey. It seems a glorious goal, to see the eastern forests filled with giants again for our pleasure, to restore the American chestnut so that we can wade through piles of nuts, set the hogs free to forage, and welcome the sons and daughters back to the hills they left to find city jobs. But the world is different now. We have rot resistant plastic wood and women and men have other choices at hand beyond chestnuts, which we have learned to live without, for better or worse.
What happens when the expatriate reappears after seventy or so years? Nearly three generations of people have come and gone since those chestnuts disappeared. How many plants and animals? Cement and asphalt have replaced the trees that moved into the plots vacated by the departing chestnuts. Every living thing must now compete with the demands of human architecture. Given this squeeze on space, who are we to deem which plant should thrive in the natural world? I doubt the oaks and the maples that moved in would approve of our decision to bring the chestnut back. They did pick up the slack after all, offering us their wood in exchange for being left alone to grow old with dignity. What of the whole economy of plants, animals, insects, and flowers that joined the oaks and maples? Will there be space left for them? Balance is a tricky thing. A small tilt in the wrong direction can lead to a killing fall. Remember the man who brought the Asian tree to make his garden look pretty. He did not know that a murderous fungus had moved in too. We cannot be sure that some errant gene in the Restoration chestnut will not sneak through all those back- and inter-crossings and behave poorly among its new neighbors.
These are the words of a pessimist who has been raised without chestnut trees. I have had no acquaintance with them, no sense of how we will prosper as the Restoration chestnut establishes new neighborhoods. People like me, contends Wetzel, “get used to a diminished ecosystem and then worry about changing it.” His vision is different. He imagines the orchard when the trees are big enough to fend off the deer and the fence comes down. The irrigation pipes will be gone and natural forces will prevail. Bear, squirrels, deer, and rodents will discover its delicious cuisine, which is fine, because in twenty years Wetzel hopes that there will be enough mast for all – the Chestnut Foundation, scientists, the animals, and the rest of us who might want to roast a few.
There would be much for the forest community to cheer. Broad shade for plants that hide from the sun, massive limbs that make safe havens for nesting birds, leaves that decay at the perfect rate – not too slow like Oak leaf or too fast like Maple – and nourish aquatic larvae. Fish will relish the fallen twigs and branches that make trustworthy underwater shelter. Even the soil might enjoy the extra dose of nitrogen, phosphorous, potassium and magnesium released from fallen leaves. In a world that needs to be rid of carbon based plastics it offers a strong wood that requires no toxic treatment to improve its utility, manna in an age when noxious chemicals prevail.
We can take it slow and plant where humans have stripped a habitat’s dignity, like deserted mountain top mines, naked and left for dead. Or fill in the blanks left when a microburst or tornado buzz cuts the landscape. Perhaps we should consider planting where indigenous American chestnuts still live, for Murkill’s prediction was wrong. Not all of the Chestnuts died. C. Parasitica (and we) wiped out 99% of the forest. One percent is left, a number that represents real trees. Some are hidden in plain site along hiking trails, one by a marsh, another near a quarry, and one more at an elevation that makes C. parastica dizzy. Many are small, but a few are almost 100 feet tall. This old generation and the new one will need time to get acquainted, learn each other’s ways, blend into a family, and blossom.