Niche differentiation between a native and an invasive species of submersed macrophyte in a subtropical reservoir

Submersed macrophytes have important ecological roles but non-native invasive species may affect biodiversity and water uses. We investigated the native macrophyte Egeria najas Hydrilla verticillata measured their maximum colonization depth its relationship with Secchi disk depth, biomass along gradient preferred depths of occurrence. The Itaipu Reservoir was monitored for seven years, during which were measured. During a separate sampling, plants collected to determine gradient. Ancova showed that both increased increasing H. faster transparency than did E. najas. Quadratic regression revealed each peaks at intermediate depths. colonizes deeper regions does patterns found in present study can be explained by underwater light and, probably, wave disturbances. preference sites indicates niches two differ, has great potential spread accumulate reservoirs.