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Nature’s Last Stand

Species depend on your yard and you

Caterpillars like that of the double-toothed prominent moth depend on a wide diversity of native flowers, plants and trees. <<photo by Doug Tallamy>>

What if your backyard were the last place for wildlife to live? What if now were your last chance to help?
    It is, and it is.
    So says Doug Tallamy, the University of Delaware entomology professor, who comes to Bowie for Earth Day to explain why.
    “He has identified an environmental storm front the likes of Silent Spring,” says Elmer Dengler of the Bowie-Crofton Garden Club, a sponsor of Tallamy’s April 21 visit.
    Nature’s future depends on how you — and each of us — do on this Earth. With every decision we make about what to plant in our gardens, we help determine which animals will make it … and which will not.
    Bringing Nature Home, Tallamy says, takes restoring native plants to your landscapes.

“If biodiversity is gone, we’re going to be gone, too,” says University of Delaware entomology professor Doug Tallamy.

    Your yard may be a lush green lawn. It may be a showcase of wonderful plants from around the world. Yet it may be barren for the birds, butterflies and bees that share it or pass through.
    Over millions of years, plants and plant-eaters have developed together in mutual dependence. Now the places they seek sustenance are depleted of the native food they evolved to consume. Over half the land area of the United States has been converted to bustling cities and sprawling suburbs.
    Birds and wildlife populations have plummeted. “There are 432 endangered and threatened bird species in North America,” Tallamy says. “That’s 200 more than just two years ago.”
    In that concrete desert, home gardens are sustaining oases. Or could be.
    “We’ve looked at the plants in our yards as decoration and ignored their vital ecological roles,” Tallamy says. “We have to change that.”

How Many Bugs Call Your Yard Home?
    Tallamy reached his conclusions — that alien species are reducing populations of plant-eaters — by counting bugs. That’s part of his job as a researcher of food webs.
    Why bugs?
    “Caterpillars drive food webs,” he says. “It takes 6,000 to 9,000 caterpillars to raise one clutch of chickadees until they’re ready to leave the nest.”
    Insects are a dietary necessity for some 96 percent of bird species during part of their life cycle, often when they’re rearing young.
    In his own backyard and neighborhood, he can see where bugs live and where they don’t.    
    He counted caterpillars in his white oak and in his neighbor’s callery pear, an Asian ornamental popular in landscaping. The count was 470 to one.
    “The alien species we plant in our yards are not,” he says, “interacting with other living things in this habitat.”
    Another popular alien, the butterfly bush, attracts butterflies with its nectar. But not a single North American butterfly species can reproduce on this Asian plant. A far better garden choice is a native butterfly garden made up of dense plantings of milkweeds, coneflowers, black-eyed Susans and Joe-Pye weeds.

Dense, diverse native plantings create excellent wildlife habitat.

    Lovely Asian azalea, hybridized for gorgeous blooms, do little to support our wildlife species. The Vaccinium genus, which includes our native blueberry, supports at least 288 different species of moths and butterflies and provides stunning autumn color as a garden shrub.
    There’s a lot to be learned about the jobs native plants do and how hard they work for their ecosystems. Tallamy and his University of Delaware team have figured out some answers.
    “Just this year,” he says, “we’ve learned how a few types of plants — such as oaks, cherries, willows, sunflowers and goldenrod — are responsible for producing most of the food in a given ecosystem. Five percent of the plants produce 75 percent of the food.”

Your Job: Bring in the Bugs
    With so many of those natives lost to development, it’s up to you to replant them.
    You are the “missing piece of the conservation puzzle,” Tallamy says.
    “When you make your property a productive ecosystem, you’ll see results. You’ll see that animals start coming into your yard.”
    To spread that message, Tallamy is on the road almost every weekend, giving talks like the one you can hear in Bowie on April 21.
    “I will do just about anything to save biodiversity,” he says. “Of all the things I’ve done in my career, this is the one that can really make a difference. If biodiversity is gone, we’re going to be gone, too.”

    Friday, April 21 at 7pm at the Bowie Center for the Performing Arts. Free with rsvp: Copies of his book Bringing Nature Home (which includes recommended native plant lists for the mid-Atlantic region) will be available for signing.
    Saturday, April 29, 8am-noon at Bowie Library, the Bowie-Crofton Garden Club Plant Sale features native plants recommended by ­Tallamy.