Tag Archives: University of Delaware

Saving Nature By Learning To Live With It: The Benefits Of Native Plants

Dr. Doug Tallamy is a Professor and Chair of Entomology and Wildlife Ecology at the University of Delaware. He is the author of “Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens.” He recently spoke to about five dozen land managers, naturalists and public service employees of Fairfax County. His appearance was funded by the same fund that produces the Park Authority’s Stewardship Brochures.

Replacing turf lawns with native plants creates favorable habitat for wildlife.

Replacing turf lawns with native plants creates favorable habitat for wildlife.

If half of American lawns were replaced with native plants, we would create the equivalent of a 20 million acre national park – nine times bigger than Yellowstone, or 100 times bigger than Shenandoah National Park.

The average, everyday homeowner can trigger dramatic reversal of environmental damage without waiting for changes to laws or for leadership from government or business. Dr. Doug Tallamy of the University of Delaware believes that and cites the saving of the Atala butterfly as an example.

In a recent address to Fairfax County employees, Tallamy said the Atala butterfly was thought to be extinct in the 1970s. Then landscapers started placing the insect’s food source, a native plant called the coontie, around houses — not to help the butterfly, but because the plant was attractive in home landscapes. The result – a butterfly thought to be extinct found the suburban plants and today appears to be on the rebound.

Tallamy believes homeowners everywhere can have that kind of influence on their environment. To those who have forgotten or who have never known an environment other than modern suburbia, he says, “There are very few places where nature is functioning as it once did.”

Biodiversity is a key term in this discussion. It simply means how many different plants and animals there are at any place. That’s important, because each plant and animal plays a particular role in the outdoors as does each player on a football team. Take away the tight end and the quarterback can’t function because opportunistic defensive players (think of them as invasive plants) come rushing through and mess things up. If you continue to remove offensive players, the offense eventually collapses.

The same is true of a machine. Take out the rivets, and the machine falls apart.

“Biodiversity losses are a clear signal” that humanity’s support structure is failing, Tallamy says.  “Plants and animals are the rivets that sustain us.”

His suggestion: Don’t think about the environment globally. Ask, “What is happening in your front yard?”

Lawns, in his view, establish privacy. They were “not developed to share that space with other living things.” He cited numbers to support that assertion — monarch butterfly populations down 90%, bobolink (and some residents may even ask, “What’s a bobolink?” It’s a bird) populations down 97%, and total bird numbers down 50% over recent decades.

Monarch butterflies are rarely seen in some places now. People in their 50s and 60s will remember seeing them commonly last century.  What’s happened? Their food source has been removed. Tallamy says they’ll come back if homeowners plant milkweed again.

Where have all the Monarchs gone?

Where have all the Monarchs gone?

“We’ve come to see plants as decorations,” adds Tallamy. Turf is one of those plants. Lots with lawns don’t clean water, don’t provide clean air, and don’t support wildlife. Developed spaces are trying to borrow ecosystems services from elsewhere, but there is no “other place” where these ecosystem services are produced. “Our yards support very little biodiversity because they were not designed to do that,” says Tallamy. “We can save nature if we learn to live with nature.”

One solution is to plant native species. That leads to biodiversity. In order for a land area to be productive, there must be large numbers of insects which feed on the plants, and in turn feed the larger animals. Our native insects cannot eat non-native plant species. Yards planted with non-native species support almost no wildlife.

In addition, not all natives are equal. Some groups of plants support many more species of animals than others. For example, native oak trees support over 550 species of butterflies and moths. The larvae of these butterflies and moths, caterpillars, are the primary food used by birds when raising their young. Lose the caterpillars and lose the birds – support the caterpillars and support the birds. By bringing nature back into our landscapes, we reconnect with nature, provide benefits for other organisms and enrich ourselves.

Aren’t small parks and preserves the answer? Tallamy says they’re not big enough. Small populations of plants and animals are subject to local extinction during natural boom-and-bust cycles. “Our natural areas are not large enough to sustain nature,” Tallamy says.

Does a yard have to be 100% native? No. Tallamy says just move in the direction of native plants, and know what the plants in your yard are doing and not doing. Some are “biologically inert.” He says, “Think of them as statues.” He told his audience there are steps “each one of you can do at your own home at your own pace.” And remember to make sure any non-native plants are not invasive plants.

So what do we do? Tallamy offers this:

  • Create corridors, natural connections between your yard and the neighbor’s yard
  • Reduce lawn size
  • Out with invasives, in with native plants
  • Use lawn only in walking areas. That’s where turfgrass shines
  • Got leaves in the fall? Put them on your flower garden as mulch. Still have leaves? Make your garden bigger.

Tallamy says that if half of American lawns were replaced with native plants we would create the equivalent of a 20 million acre national park – nine times bigger than Yellowstone, or 100 times bigger than Shenandoah National Park.

The environmental movement intensified in the 20th century and continues today with us. It’s our turn to choose our legacy. What you protect today will still be around tomorrow for your children, and those children will form their outlook toward the environment from you. As Tallamy told his listeners, “There is no better way to expose children to nature than to bring nature home to them.”

Written by Dave Ochs, manager, Stewardship Communications