By Elizabeth Constance Williams
Larry Stevens is a naturalist at Chattahoochee Nature Center. Starting with a lifelong passion for nature, he continued with independent research and collaboration with the horticulture department at CNC. Stevens has written articles on invasive species for Smithsonian and presented them at TEDx, yet his knowledge is most evident on the trails themselves.
During the interview, we collected samples of non-native and invasive plants, where he emphasized how these terms are not synonymous an important distinction, such as “things like daffodils are non-native, but not invasive. With our habitat restoration, we remove plants that outcompete our locals… a plant needs air, soil, nutrients, and sunshine. The ones that overgrow, like wisteria and English ivy, cover up and deny growth to native plants.” The most worrying of these smothering plants isn’t Kudzu, it’s English ivy. English ivy kills trees, growing over and choking native plants, unlike poison ivy and other native ivies.
At the Nature Center, however, one of the biggest threats is privet, originally introduced as a hedge in the 18th century. In the spring, it blooms with white flowers, and in the fall, it produces little purple berries, which birds eat and subsequently spread. “If you go for one of our canoe trips on the river, you’ll see privet all along,” says Stevens.
Many invasive species are brought over for gardening. Butterfly bush, Nandina, Chinese wisteria, Elaeagnus, and Mimosa were planted for their beauty, without thought for the environmental impact. Nurseries once sold these invasive species. However, in recent years, the demand for native plants has grown, and the number of invasives sold has declined. Other plants, like Japanese stiltgrass, had practical uses, such as packing material. However, once the packages were opened, the plant was discarded and therefore spread. Other invasive plants have uses, like kudzu. Once used for erosion control, now eaten and woven into baskets, kudzu’s growth cannot be kept up with.
Invasive species are so prolific in other environments because they have no natural balance: “they [invasive species] have no enemies, and nothing will eat them.” However, some adaptation still happens. The beaver at the Nature Center once refused to eat privet but now does. We also encountered a Joro spider. “There’s a debate on whether the Joro is invasive or not. The thing is, it’s outcompeting our local orb weavers,” Stevens says. Joro’s also build 3D webs, trapping small birds, unlike native spiders.
Identifying invasive species can be difficult, and it requires knowledge. Some native and invasive species are difficult to distinguish between, such as dayflower. The native type has a 3rd blue petal, and Habitat Restoration volunteers must be trained to properly identify between them.
At CNC, invasive removal happens through several different methods. According to Stevens, “We’re using our hands and are prepared with gloves and closed-toed shoes.” Some tools used in this work are picks, shovels, and a Pullerbear weed puller. When roots cannot be fully removed, carefully contained herbicides are used. To protect native plants, they are directly applied instead of sprayed and dyed with ink to track their progression.
On an individual level, members of the community can make sure to plant natives and remove non-natives from their yards, as well as never releasing pets into the wild. It makes a real difference. 10 years ago, the far bank of Kingfisher Pond was covered in English ivy; now it’s completely clear. Stevens recommends buying from the Nature Center’s native plant sales and otherwise planting favorites like bee balm.
