Date of Award


Document Type


Degree Name

Master of Science (MS)


College of Science and Mathematics



Thesis Sponsor/Dissertation Chair/Project Chair

Dirk Vanderklein

Committee Member

Paul Bologna

Committee Member

Matthew Schuler


Purple loosestrife (Lythrum salicaria) is an invasive plant that has degraded many wetland habitats since its initial introduction to the United States in the early 19th century. To aid in managing purple loosestrife, it is important to study how purple loosestrife grows under variable environmental conditions compared to common native species, which can help managers understand which habitats are most at-risk of invasion. High or low salinity and pH are often barriers to plant growth, and the stress caused by these environmental conditions can cause plants to deplete their starch reserves. If native species are more negatively affected by stressful environmental conditions than the invasive purple loosestrife, then habitats with those environmental conditions would likely experience a decline in native plant populations and an increasing population of purple loosestrife following establishment. To test the different responses of native and invasive plants, I grew purple loosestrife, native winged loosestrife (Lythrum alatum), and cattail (Typha latifolia) in soil with different salt concentrations (low, medium, and high), as well as soil with modified pH (acidic, neutral, and alkaline). The low-salt and neutral pH soils were considered control growth conditions. Purple loosestrife and winged loosestrife had stunted growth in alkaline conditions and in high soil salinity treatments, and did not produce as much biomass or starch when compared to the control soil treatments. Cattails were smaller in the high salinity and acidic treatments and did not produce as much biomass or starch compared to the control treatments. These results indicate that purple loosestrife and winged loosestrife respond similarly to stressful soil conditions, which has important management implications.

File Format


Included in

Biology Commons