Newhart, PJ, Department of Biology, Bucknell University, 1 Dent Drive, Lewisburg, PA 17837, pjn009@bucknell.edu; Martine, Christopher T., Department of Biology, Bucknell University, 1 Dent Drive, Lewisburg, PA 17837, ctm015@bucknell.edu.
The newly problematic species Lysimachia vulgaris (Garden Loosestrife, Primulaceae) is plaguing the waterways of central Pennsylvania. Garden loosestrife is native predominantly to Europe but can be found in eastern Asia and northern Africa. The plant is rhizomatous and will aggressively colonize river environments. In particular, it is threatening important river brash environments, which are semi-aquatic conglomerates of Justicia plants that form important environments for fish spawning. In order to protect these fragile conditions, it is imperative to understand how to best control and mitigate invasive L. vulgaris populations. To achieve this, I have devised a set of conditions to test on plots of L. vulgaris on an island in the West Branch of the Susquehanna River near Bucknell University. I have observed and recorded the features of the habitat, organismal interactions with plants, and where on the island they are growing (as of Oct. 2024). Once this was determined, I sought to assess the efficacy of various types of mechanical removal and the introduction of physical barriers. For all of the treatments, roughly a 0.5m plot was marked with dowel rods and tape and labeled according to their corresponding treatment with a number representative of treatment. 2 replicates were completed in 2 separate plots of the island. To determine what mechanical removal technique may be best, I dug a roughly 0.5m deep hole and transplanted soil from an unafflicted area of the island into it, as well as cutting the plants at the base, pulling the plants as best I could, and ‘tilled’ the soil by breaking it up at the surface with a shovel. To test physical barriers, a similar 0.5m deep hole was dug and was replaced with soil from the same aforementioned location, then plots were either lined with weed mat/geotextile fabric, landscape edging, or were placed in a flowerpot. In the latter treatment, the flowerpot was punctured with holes every 2cm of its 30cm depth in the hopes that I could determine how deep the roots would attempt to spread. These plots will be monitored weekly until the plants die, and the results will be gathered concretely come spring when I can observe best how well the plants overwinter. With the information gathered from this project, I hope to be able to find an ideal method to control the spread of L. vulgaris to protect vital river environments, as well as gain important knowledge of the plant in general to determine which areas are most at risk for its spreading. At this current time, the environment has been examined and associated data has been collected and the plots have been set up to observe.
Invasive species, River scour, Eradication, Lysimachia
