It’s easy to find a roadside or lot boundary overgrown with kudzu. When the Asian plant moves into an area, it does so quickly and totally, smothering trees and native plants alike. What’s left is a monoculture – one plant, spreading like crazy.
Kudzu isn’t alone, either: In the South and across the U.S., we have introduced some 3,300 invasive species that have penetrated the existing ecosystems, Doug Tallamy says. Many of these, kudzu included, were brought here as ornamental plants, just to escape captivity and rampage across the landscape like real-life B-movie monsters.
“The notion of letting nature take its course no longer applies, because those plants are here without any of their natural enemies,” Tallamy says. “There is nothing to keep them in check. That’s what nature taking its course is.”
Yet Tallamy, chair of the Department of Entomology and Wildlife Ecology at the University of Delaware, author of “Bringing Nature Home” and co-author of “The Living Landscape,” brings a message of hope: We can stop these monsters!
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Combating the destruction of native ecosystems is as simple as actively planting native species in your lawn. On Sept. 27, Tallamy and “The Living Landscape” co-author Rick Darke team up for a lecture and book signing at the Fearrington Barn in Fearrington Village, sponsored by the N.C. Botanical Garden. Tallamy will explain why and Darke will explain how to maintain a native-oriented landscape.
It takes a shift in thinking or two, but it’s possible, they say – and it’s essential if we want to avoid losing beloved species like songbirds, perhaps forever.
“I don’t use the word nature,” Rick Darke says. “Nature is no more helpful to me as an explanation than the Tooth Fairy is.” Darke, an experienced landscape consultant, lecturer, and photographer, sits in his office, laughing at the antics of a nuthatch walking upside-down outside the window. He loves the natural world, sure, and understands it well, but rejects a common term like nature because it implies a separation between humans and the natural world, and also suggests some kind of external force that comes along and tidies up disturbed ecosystems. Rather, in the competition between the existing, balanced ecosystem and the newcomer with no predators, there are winners and losers – and the losers die.
“When somebody tells me I should embrace these local ecosystems, it makes me bristle,” says Tallamy. “I am not going to embrace mass extinction.” As he says and as he writes in his books, so much trouble comes from plants transported outside their original ecosystems. Many of these have the “pest-free” label, and what this means is that local insects can’t eat their leaves.
Plants, however, are the lowest trophic level – this means that all the food on the planet, as Tallamy puts it, originates with their ability to photosynthesize. If nothing can eat the leaves on a plant, then “pests” – local insects, that is – aren’t around, and neither are the things that eat them: no bugs equals no birds, and soon the ecosystem is disrupted.
Yet the message of Tallamy and Darke’s book and lecture, again, is a positive one: change can start in your own yard. The idea, Darke says, isn’t to tear out your lawn and replace everything with native plants all at once – he’d rather you didn’t, actually, as large disturbances provide opportunities for fast-growing invasives. Rather, the idea is to do a little at a time. Between work and travel, he and Tallamy are too busy to dedicate superhuman amounts of time or effort to gardening anyway, and they don’t expect their readers to work any harder than they do at it. It shouldn’t feel like a burden, Darke says.
“I can tell you, from our own property right here, that it doesn’t take long,” Tallamy says. Fifteen years ago, when he bought the place, the yard had been mowed for hay. “We now have 54 species of breeding birds here. It looks like a forest. These trees have grown so fast. I’m staring at an oak tree right now that’s gotta be 30 feet tall, and I planted it from an acorn.”
And Darke, the man who won’t say “nature,” has another way of taking the pressure off. Rather than shout “grow native plants or you’re going to hell,” he says wryly, he thinks that abandoning even the concepts of native or invasive organisms makes sense. Rather, think about what function you want a plant to have before you add it to the landscape. If you want birds, if you want butterflies, if you want a low-maintenance, balanced landscape that doesn’t need fertilizer or pesticide, the most sensible plants will, appropriately, be plants that evolved in the area.
“It’s time to stop worrying where plants come from. Let’s stop this endless debate about native and exotic,” Darke says. “If we put the focus on functionality, it takes care of itself.”
Reach Hill at firstname.lastname@example.org
Doug Tallamy and Rick Darke will give the Jenny Elder Fitch Lecture from 2-4:45 p.m. Sept. 27 at the Fearrington Barn in Fearrington Village, Pittsboro. The event is free but preregistration is required.
Info: 919-919-962-0522, ncbg.unc.edu
Keep in mind ...
A few tips from Doug Tallamy and Rick Darke on the impact of invasive species and how to encourage native plants and habitat:
▪ Ecosystems don’t follow political boundaries! A plant from Colorado can be as much an invasive species in North Carolina as a plant from Europe or Asia.
▪ This is not a hypothetical situation: familiar organisms have already suffered from the phenomenon Tallamy and Darke describe. The monarch butterfly’s population has plummeted after declining numbers of a single host plant, the milkweed, and some songbird species are already declining in the South.
▪ In a balanced ecosystem, leaf “damage” will only impact about 4 percent of the plant. When encountering half-eaten leaves, think instead of the insect being fed which, in turn, supports the local food web.
▪ Only 3 to 5 percent of the continental United States remains in an undisturbed, natural state, Tallamy writes in “Bringing Nature Home” – and these natural spaces are isolated islands, rather than contiguous wilderness.
▪ Hummingbird-friendly flowers also provide food and shelter for other living things – and they don’t need filling!
▪ Undesired plants are easier to knock out when they’re seedlings, so learn what they look like.