Position of samples taken on the longitudinal profile of Bednja River with regard to substrate composition in a Simprof test cluster analysis based on Bray-Curtis similarity of Odonata assemblages. Odonata abundance values (Log(x+1)) transformed prior to analysis. Substrate abbreviations: MESO = mesolithal (hand-sized cobbles), MICRO = microlithal (coarse gravel), PSA = psammal (sand), AKA = akal (fine to medium-sized gravel), XYL = xylal (woody debris), ARG = argyllal (clay), TECHNO = technolithal (artificial blocks).