Abstract
The study aimed at estimating the reliability of river classification based on macrophytes under differentiated habitat conditions. The studies were carried out between 2002 and 2005, within the EU STAR project and two other local projects. Factors taken into consideration included: shading, habitat modification, and lengths of the survey sections. Polish lowland watercourses were surveyed. The analyzed streams represented a wide range of degradation. Several macrophyte-based metrics were evaluated, including major European systems (MTR, IBMR, TIM, MI, RI) and diversity metrics (number of species, Shannon diversity index, total cover). The reaction of the macrophyte-based metrics examined to habitat factors was compared. It was proved that some of the metrics appeared to be resistant to different sources of variability, thus confirming their usefulness for river monitoring.