Allelopathy in the non-native macrophyte, Myriophyllum spicatum and its influence on trophic dynamics in aquatic systems

Non-native macrophytes structurally impact aquatic assemblages, yet little is known regarding how they influence energy pathways in freshwater ecosystems. Allelopathy in Eurasian watermilfoil- Myriophyllum spicatum has been shown to target basal epiphytic organisms resulting in differences in assemblage structure of colonizing epiphyton between M. spicatum and native M. sibiricum. I conducted a growth chamber experiment to investigate the hypothesis that differences in assemblage structure of colonizing epiphyton between these two macrophytes influence trophic dynamics within aquatic systems. My data suggest M. spicatum produces higher concentrations of allelochemicals, resulting in a more diverse epiphytic assemblage compared to M. sibiricum. This could result in potential transformation of trophic dynamics by decoupling carbon as it flows from primary producer to primary consumer. This work identifies a contributing mechanism responsible for M. spicatum invasiveness and provides new insight in its ecology and management of this non-native macrophyte.