The Effect of a Competitor Species on the Seedling Development of Lythrum salicaria

Abstract

Purple loosestrife (Lythrum salicaria) is a plant that was originally introduced to the United States as an ornamental, but was soon found to be invasive in wetland habitats. Lythrum reduces plant and wildlife diversity in these areas and causes the extinction of rare species. Our research was conducted to determine if another species planted along with Lythrum would act as a competitor and reduce the invasive characteristics of the plant. We also compared this with its invasiveness in different types of media (peatmoss and sand) to determine if its ability to take over was related to the media in which it was growing. The competitor species we chose was cordgrass (Spartina pectinata) because it is a typical grass native to wetlands. We varied the planting times of the Lythrum and Spartina in different pots and recorded germination rates and the final dry weights of both species. We found significant differences among the plants at each planting time and between the plants in the peatmoss and sand.