Preventative Control Of The Invasive Japanese Stiltgrass In Stream Restoration

Japanese Stiltgrass (Microsgtegium vimineum) is one of the most invasive species on the East Coast and poses a constant problem to restoration ecologists. Japanese Stiltgrass is constantly invading restored wetlands and streams, and the most common solution is to use non-selective herbicides, like glyphosate, to reduce invasion. However, herbicide often comes with its own negative consequences to the ecosystem and can even lead to reinvasion after it is applied. This paper looks to study the current available alternatives to herbicide for reducing invasion and then test them in the field. According to the stress-disturbance invasion model, high levels of stress can help reduce invasion and therefore promote native species, so we looked at cultural methods that acted as stress agents to our invader. We chose to implement four treatments, canopy shade, sawdust and wood mulch soil amendments, and double seeding rates, as well as a combination of these treatments. Over our two-year field study of a restored stream, we found that sawdust was the most effective at reducing M. vimineum, and that shade heavily promoted natives to compete with our invader. This suggests that for future stream restoration projects that managers should consider implementing sawdust into the topsoil layer and encourage large shade trees around the disturbed areas.