“…Since catchment geomorphology and climate-related variables are often strong predictors of macroinvertebrate assemblages (Richards et al, 1996;Hawkins et al, 2000;Verdonschot and Nijboer, 2004;Chaves et al, 2005), sites within the same WFD type that were based on these factors are expected to represent relatively distinct ecological units for invertebrate communities (Verdonschot, 2006a;Sa´nchez-Montoya et al, 2007). Alternatively, in bottomup approaches, aquatic biological data are used to group similar stream sites (e.g., Wright et al, 1984;Parsons and Norris, 1996;Marchant et al, 1997;Ehlert et al, 2002;Heino et al, 2003;Lorenz et al, 2004;Dodkins et al, 2005;Sa´nchez-Montoya et al, 2007).…”