Many of us are familiar with the power of kudzu and its ability to overtake anything in its path. You may have memories tasting the sweet nectar of Japanese Honeysuckle, known to some as “liquid candy.” Maybe you’ve seen—and even purchased—a pot of English Ivy from a plant retailer, or enjoyed picking and eating wineberries from prickly pink stems in the summer. If any of these apply to you, congratulations! You’re already familiar with some non-native invasive plants (NNIPs) that are widespread throughout the United States. What you may not have known is how detrimental these plants are to wildlife, native species, and entire ecosystems.
There’s more where those came from, too. According to the U.S. Fish and Wildlife Service, more than 4,300 NNIPs have been identified across the country. NNIPs are a costly challenge for conservationists; the North Carolina Invasive Plant Council estimates annual spending on invasive management nationwide at $34.7 billion. These plants pose a threat to our economy, human health, biodiversity, ecosystem quality, wildlife, and more. Fortunately, currently only about 25 NNIPs are highly problematic in the mountains of Western North Carolina, and even fewer in DuPont State Forest. The photos in this article show some of the NNIPs that do exist here in the Forest.
Image of mature Miscanthus sinensis, or Chinese Silvergrass
Image of clustered pink flowers on Spirea japonica, or Japanese Spirea.
Image of reddish stem, leaves, and white flowers on Lonicera japonica, or Japanese Honeysuckle
Image of yellow seeds open to reveal red berries on Celastrus orbiculatus, or Oriental Bittersweet.
Image of serrated leaflets on Rosa multiflora, or Multiflora Rose. Emphasis on the toothy hairs at the base of the stem, a key identifier of this plant.
Image of stem and flowers on Lespedeza cuneata, or Sericea Lespedeza
Image of white flowers on Multiflora Rose, which bloom between April and June.
Not all non-native plants are invasive, but all invasive plants are non-native. Invasive plants quickly and aggressively “invade” and displace native plant life in ecosystems. They encompass a broad variety of plants, including trees, vines, shrubs, herbaceous plants, and aquatic plants. Many invasive plants have been present in the U.S. for centuries; such species were often originally introduced intentionally as ornamental plants. Others, such as Lespedeza cuneata—commonly known as Chinese bushcover or sericea lespedeza—another plant present in DuPont Forest, were introduced to provide wildlife cover and forage, roadside erosion control, and mine reclamation.
Once established, NNIPs often outcompete native plants for light, moisture, and nutrients, and they use their competitive advantage to overtake land space. Native plant species have co-evolved within their native ecosystems alongside a rich and interconnected diversity of flora and fauna. A healthy native ecosystem “self-balances,” with native species providing critical links of the food chain, along with habitat, soil nutrition, and other functions. Native insects often cannot, or will not, eat non-native plants. When native plants disappear, beneficial insects disappear, impoverishing the food source for birds and other animals.
Alliaria petiolata, or Garlic Mustard, displays the competitive advantage of producing allelopathic compounds that inhibit seed germination of other species. Other NNIPs—such as Celastrus orbiculatus, or Oriental Bittersweet—produce huge amounts of seeds that are subsequently spread by bird and wildlife consumption. Spiraea japonica, or Japanese Spirea, disperses seeds in waterways and are thus often present on stream banks. Oversaturation of invasive plants in an ecosystem can degrade root structure diversity leading to erosion, diminished water quality, and compromised habitat for fish and aquatic life. Loss of biodiversity results in monocultures—i.e. single crops in a given area—that pose a threat to terrestrial wildlife for food and habitat and can increase fire risk. These challenges arise when plants such as Chinese Silvergrass—also found in DuPont Forest—overtake entire fields adjacent to forests.
Needless to say, there’s a problem to solve here. All efforts in controlling NNIPs are needed to protect our native ecosystems, and it’s time to get boots on the ground in DuPont! Stay tuned for the next newsletter, where we’ll return to discuss important methods for NNIP control!
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