Effect of light on particulate and dissolved organic matter production of native and exotic macrophyte species in Patagonia

Biological invasions are one of the main drivers of changes in ecological features in aquatic environments. Invasive alien species may have far-reaching effects on the host environment that need to be explored. In this study, we compared particulate and dissolved organic matter (POM and DOM) production from two common Patagonian wetland plants, one native (Eleocharis pachycarpa) and one exotic (Potentilla anserina), under different light conditions (exposed or not to ultraviolet radiation (UVR+, UVR-) and darkness). Our results indicated that when exposed to UVR both macrophytes differed in their POM production and DOM release: while in E. pachycarpa we observed an increase in the POM production P. anserina released significantly higher amount of DOM. The DOM produced by the exotic species showed lower photoreactivity, and had more colour than that produced by the native E. pachycarpa. The invasion by macrophytes may produce changes in the stoichiometric balance and ecological relationships that could modify the characteristics of wetland food web.