Turning away the invaders: Natural stream banks key to healthy waterways
Take a walk in mid-May, and you probably won’t get far before finding somebody bent over a garden bed, weeding. Eric Romaniszyn and Christine O’Brien were doing just that on a warm Thursday afternoon, but they weren’t in a garden — they were on a stream bank. Specifically, they were on the bank alongside Richland Creek at Vance Street Park in Waynesville.
“We try to take every little piece out,” Romaniszyn said, yanking a clump of Japanese knotweed roots out of the dirt and stowing them in the trash bag by his side.
Knotweed is an invasive, one of the species that Romaniszyn and O’Brien work to combat through their work with Haywood Waterways Association. It’s not part of the natural ecosystem here, but it grows so aggressively that even the tiniest piece of vine dropped in the stream can grow roots and anchor itself downstream. And once it starts growing, it just keeps on doing so, to the detriment of the natives.
“Invasive species can outcompete native species,” Romaniszyn said. “They might not produce the food that wildlife needs, so at Vance Street Park there’s a lot of Japanese knotweed taking over. It’s really invasive and can disrupt the ecological processes.”
Invasives tend to have shallow root systems that don’t hold soil in place as well as native trees and shrubs, so a thicket of knotweed or multiflora rose can quickly become large enough to make stream access for fishing or photography difficult while doing little to prevent erosion. And that, in turn, causes problems for the aquatic species that live in the water.
Several years ago, Haywood County Extension did some restoration work on that same stretch of stream, redirecting water flow towards the center and reducing the angle of the stream banks to decrease erosion and replacing invasives like knotweed, multiflora rose, oriental bittersweet and Japanese honeysuckle with native plants. Unfortunately, the soil delivered for the project was contaminated with knotweed seeds, and there’s no easy way to remove the plant.
“Unless you’re using chemical means, which we don’t recommend near a stream, it will take going out there and pulling them a couple more times, but once you get in there, you can plant some native species,” Romaniszyn said.
Romaniszyn and O’Brien were there for their third pass at the stream section, banks that have seen a lot of improvement since the first time they attacked them in the spring of 2013. With the help of a retinue of volunteers, they hauled more than 20 garbage bags full of invasives away from the creek last year. This time, they brought reinforcements to carry on the fight after they’ve left — black willow cuttings.
“They’re easy to transplant,” O’Brien explained. “They tend to have a good, large root base. They do well in these wet soils, and they are natural so they provide habitat for wildlife. They provide good shade cover for the streams.”
The pair planted 20 seedlings on the stream bank, expecting a 70 to 80 percent success rate. When mature, black willows typically reach 30 to 60 feet in height and can live up to 100 years. Their bark, stems and twigs provide food for deer, rabbits and beaver. Insects eat their nectar, and many caterpillar species eat their leaves, which also provide cover for a variety of birds and small mammals. Woodpeckers and raccoons find homes in their cavities.
As all gardeners know, weeding any patch of soil is a never-ending battle. But for O’Brien and Romanizsyn, the water is worth it.
“It benefits the waterways,” O’Brien said. “It keeps the natural habitat healthy. It keeps the bank from eroding, which leads us to healthy streams.”