Phenolic Levels of Invasive Myriophyllum Spicatum and Native Elodea Canadensis at Different Temperatures,"

TIffany Balling, Sacred Heart University

Eastern Colleges Science Conference, Wilkes-Barre, PA, April 2017. E-107. Retrieved from

Mentored by LaTina Steele.


Eurasian watermilfoil (Myriophyllum spicatum) is an invasive aquatic plant that may dominate lakes and waterways throughout the U.S. It is known to crowd out native plants and create dense mats that interfere with recreational activity. Milfoil also produces allelopathic chemicals, such as phenolics, that may give the invasive plant a competitive advantage over native species like Elodea canadensis. In a laboratory competition experiment, we tested the effects of competition and temperature on growth, nutrient uptake, and phenolic levels in both Myriophyllum spicatum and Elodea canadensis. The experiment consisted of six replicates each of six treatments (M. spicatum alone, E. canadensis alone, and the two-species grown together, with each combination of plants grown at ambient temperature and with the temperature increased by 2°C using individual aquarium heaters). After three weeks, the length of each plant fragment was measured, the number of branches on each fragment was counted, each fragment was weighed. One water sample was collected from each tank, and nitrate and phosphate concentrations were measured. Plant fragments were frozen for phenolic analysis at the end of the experiment. In general, M. spicatum showed more growth and produced more phenolics than E. canadensis'. However, at higher temperatures M. spicatum produced less phenolics than at lower temperatures. Based on the temperatures effect on the production of phenolics, M. spicatum can produce more phenolics at lower temperatures making this species very invasive at lower temperatures. As the climate continues to change there could a decrease in M. spicatum in certain areas.