Cure Yourself of Tree Blindness

Spruce, Fir, Tamarak -AWARE Simcoe photo

By GABRIEL POPKINAUG New York Times

For several years, I’ve led tree walks in Washington, D.C. I start by asking participants who they are and why they want to spend precious hours looking at trees. My students are nearly all highly educated, successful people who work impressive jobs, speak multiple languages and effortlessly command sophisticated computers and phones. Yet most know barely the first thing about the trees around them. They want to change that.

There was a time when knowing your trees was a matter of life and death, because you needed to know which ones were strong enough to support a house and which ones would feed you through the winter. Now most of us walk around, to adapt a term devised by some botanists, tree blind.

But here’s the good news: Tree blindness can be cured. A few years ago, I knew two types of native trees, oak and maple. I considered all conifers to be pines. Then in 2012, I took an ecology course in Wisconsin in which we learned to identify 14 tree species — which, in the chilly upper Midwest, actually gets you pretty far. Suddenly the largest, most conspicuous living beings in my environment were no longer strangers. The trees lining my street in Madison with the rough, saucer-size leaves were basswoods. The giant in my backyard with the diamond bark and opposing rows of leaflets neatly lined up like soldiers was an ash.

Now I live in the nation’s capital, where the milder climate and people’s propensity to plant species from elsewhere (Japanese cherries, anyone?) have given us more than 300 types of trees. Yet with just a few rules of thumb, it’s easy to start making sense of them, too. By noticing that branches grow opposite each other, rather than alternating back and forth on either side of a limb, you can narrow a tree down to maple, ash, dogwood or a handful of introduced varieties. From there the leaf shape gives away at least the genus, if not the species.

Just naming trees might sound a bit like a parlor trick to impress your friends. But it’s also a way to start paying attention. Then you notice more interesting things. Trees put on one of nature’s great sex shows. Each spring they break their winter dormancy with a burst of genitalia, also known as flowers. Some, including the famous cherries, are insect-luring exhibitionists; others, such as the oaks, are more coy, relying on the wind to help consummate the mating act. Take a moment to watch and listen to a flowering redbud tree full of pollen-drunk bumblebees. I promise you won’t be bored.

Tree death, like tree sex, can reveal deeper truths. You may have seen bare trunks with branches that fork over and over in perfect symmetry (that opposite branching again). These are ash trees, victims of the deadly emerald ash borer, which is thought to have arrived in shipping pallets from Asia. Beyond the aesthetic and ecological loss, and just plain tragedy, the ash carnage costs society a huge amount of money, as parks departments and homeowners must either treat ash trees or have them cut down.

Luckily, not everything in tree world is so dismal. The trees around us can uncover forgotten history. Sometimes a huge oak rises in a yard or in the midst of a much younger woods. These “witness trees” once marked the edges of farm fields. An oddly straight line of junipers or locusts likely signals an old fence row. Neighborhoods built in the 1960s might be lined with once-loved, now-hated Bradford pears; older ones may feature towering willow oaks with roots bulging out of undersized tree boxes. Parts of Paris, New York and, appropriately, London, are practically monocultures of London plane trees, once favored because they could survive these cities’ fetid air.

Trees can also tell us how well we’re managing our environment today. Many eastern forests, including Rock Creek Park, the wild green vein running down Washington’s center, have an understory dominated by American beech. Beeches are slow to get going, but they’re almost unmatched at growing in shade and being unappetizing to deer, which are wildly overpopulated in much of the country. Unless we find a way to manage our woods, using predators and periodic fires, we’re probably on our way to species-poor forests dominated by beeches. As much as I love the tree’s smooth, elephant-skin bark and brittle leaves shivering on their branches through the winter, I don’t think an all-beech future is one I want to see.

Some may want more practical reasons for learning trees. If so, I offer that knowing your trees opens up an abundant and entirely free food source. Those in the know can gorge on juicy native mulberries and serviceberries in the spring, and persimmons and pawpaws in late summer. That’s to say nothing of tree nuts, which carpet the forest floor in fall. Pecans, walnuts, hickory nuts, beech nuts; with proper preparation, they’re all edible. For Native Americans living in California before European contact, acorns were a staple more important than corn. Yet today they’re a specialty item, largely limited to the occasional D.I.Y. foraging workshop.

We’re so used to eating domesticated plants that the idea of eating wild tree parts seems strange, primitive and possibly dangerous. As a result, we’re letting billions of dollars’ worth of free, high-quality food go to waste. This, reader, is madness! I’ll admit, however, that I’m among the mad. Roadside tree fruit is just an occasional supplement to my diet, and I haven’t yet found the patience to leach the bitter tannins out of acorns. For me, learning about trees is more about seeing, and knowing. It’s about not being a stranger in my own country.

And it’s about not letting the built environment make me too tame. When you engage with a tree, you momentarily leave the human-created world. Look at an American elm in winter, its limbs waving like Medusa’s snaky hair. The elm may grow along streets and sidewalks, but there is nothing tame about that tree. In cities, where animals feast on human gardens or garbage and most landscape plants are domesticated cultivars, native trees are the last truly wild beings.

Yes, people may look curiously if you stop to study a tree. But so what? Let yourself go a little wild.