Are ecological indices based on macrophytes communities pertinent tools to monitor ecological potential of Walloon reservoirs?

Diversity and trophic metrics based on macrophyte communities were calculated to test their pertinence to assess the ecological potential of Walloon reservoirs (Belgium). The BE-FL method (four complementary metrics) and the United Kingdom method (five metrics calculated using information on taxonomic composition and abundance of macrophyte species and groups of such species) were tested.
Highly significant correlations were found between the chemical variables (o-P (mg P/l); P tot (µg P/l); NH4+ (mg N/l) DCO (mg/l) Cond (µS/cm), the phytoplankton assemblage index, Q (Padisak et al., 2006) applied for the same reservoirs (Descy et al., 2010).
and trophic metric LMNI and between them and the abundance of disturbance indicators (V). Groupe of macrfophyte species metrics do not necessarily provide any direct information on the quality or degree of degradation of the environment from which the sample was taken, whereas trophic indices do.