Some perspective on an unloved tree

Friday, March 25, 2016

I recently wrote an op-ed for the New York Times, about the Bradford pear tree. The Bradford pear is not my favorite tree or even a tree I particularly like, but I thought it needed a defender, because it has, in my opinion, been unfairly made a scapegoat for all kinds of problems not of its own making.

Riverdale pear

Though it is a tree, and therefore ostensibly part of “nature,” the Bradford pear is unquestionably a human creation. It was brought into being by scientists, promoted by a first lady and countless nursery companies, disseminated in what must have been a veritable orgy of street planting, and now hacked into awful shapes by utility crews trying to keep it from dropping branches onto power lines. Birds spread its seeds to parks and stream banks and other “natural areas,” where it offends people who want to see only native plants.

But I don’t think it’s the pear we should be offended by. We should be offended by ourselves. The pear thrives precisely where we have abused nature, which is to say almost everywhere. (In the interest of accuracy, I should note that it’s the Callery pear that is ubiquitous. Bradford is a specific cultivar of Callery pear that comes from nurseries, but that can hybridize with other pear varieties to produce viable seed.) Where I live, in Maryland near the Anacostia River—the sad, channelized, silted-up sidekick of the Potomac—the abuses have been piled on top of abuses so we can’t see them anymore. In the past four centuries, what was once forested wetland has been drained, cleared, plowed, planted in tobacco and other crops, perhaps grazed after the soil eroded and wore out, dumped on and then abandoned by industries whose skeletons still populate the landscape, and now carved into a million suburban lots. The Callery pear, which loves disturbed soil, forest edges and sunny areas, does wonderfully here.

When you write about some piece of the world, you become sensitized to it. Annie Dillard described this as being like a bell, ready to be rung. This spring, I am being rung by the Callery pear. I have never noticed before how ubiquitous it is. Now I see the trees everywhere, rising from the land like puffy white clouds.

It baffles me that people walk out of their houses, get into their cars, drive on four-lane highways past strip malls to little patches of green, and see non-native plants as the piece of the landscape that is out of whack. Yes, Callery pear may compete with native species for resources, but I highly doubt it has ever driven anything extinct. In fact, I wonder if any plant has ever been responsible for an extinction*. Our houses and cars and roads and strip malls eradicate native plants for more effectively than any introduced plant ever will.

I am not arguing, by the way, that we should just open our borders and let in all species. Introduced species can cause huge problems. One species of fungus, Batrachochytrium dendrobatidis, has driven more then 100 amphibians to extinction—mostly in the tropics so far, but it could arrive here. The fungus that causes white nose disease has reduced populations of some of our native bats by more than 90%. Chestnut blight (a fungus) and Dutch elm disease (a fungus spread by an insect) have all but wiped out two of our great native trees, and hemlock woolly adelgid (an insect) and emerald ash borer (another insect) are currently destroying two more. What do all of the above scourges have in common? They’re not caused by plants. And yet, it’s the introduced plants that get people all worked up. See here and here and here for examples of fury toward the Bradford pear. Just try to find anything approaching this level of anger directed toward a fungus or an insect!

If we care about native plants, cutting down pear trees is not the answer. Instead, we should better fund our port inspection service, so it can effectively screen cargo entering the country for plants that could be carrying new diseases or pests. We should also jackhammer up most of our streets and demolish the strip malls and box stores. We should all move into tiny apartments and become vegetarians and get rid of our cars and do everything we can to minimize the amount of land we need to sustain ourselves, as E. O. Wilson seems to be suggesting in his latest book. The native plants don’t need us to spend weekend mornings ripping out weeds; they mostly just need unfragmented, undisturbed land and relief from diseases and pests.

Of course we’re not going to give them that, because we’re doing quite well with our cities and suburbs and exurbs and farms and our global trade, thank you very much. In fact, we’ve never had it better; we are the wealthiest and most comfortable society the planet has ever been home to, and that’s largely a result of how we’ve exploited land and moved species around. What we call “invasive plants” are really a byproduct of our own behavior.

They’re also a quintessential first-world problem. They’re what we worry about when we don’t need to worry about having enough food to eat, or being sick, or being killed in a war, or working three jobs to get by, or breathing dirty air or drinking polluted water. In a world with so many urgent problems to solve, we should question the impulse to tidy up little pieces of nature. What else could we be doing with our time and energy? Maybe fighting inequality? Saving our remaining old-growth forest? Saving lives?

It’s time to get over the Bradford pear. There are far more important things to worry about.

*Originally this sentence ended with “…or even an extirpation.” My biologist friends have convinced me that extirpations have been documented where invasive plants are widespread. I would still argue that the question of responsibility (human versus plant) should be further explored, but will leave that for another time.