Our objectives were to offer insight into the characteristics of the physical
environment in the River Danube in Serbia; and to show the relationship
between selected environmental factors and the composition and abundance of
macrophyte species. The macrophyte survey method followed the European
Standard EN 14184, applying Kohler?s five-level descriptive scale. Principal
component analysis was carried out to examine the variation in aquatic
vegetation, and to analyze the effect of environmental variables on the
aquatic vegetation, redundancy analysis was used. To build a simpler model
with fewer explanatory variables, yet sufficiently explaining species
variability, forward selection of environmental variables was done. Our
results confirmed that physical environmental factors significantly influence
the establishment and structure of macrophyte vegetation, with the level of
hydrological connectivity to the main river channel being the most important,
followed by the transparency of the water column, sediment texture and
water-flow velocity. In order to inspect the individual relation between
best-fitted plant species and each of selected environmental variables,
Spearman?s rank correlation coefficients were calculated. We have
distinguished plant species with preferences to specific combinations of
analyzed factors. Our results provide a background for future, more specific
studies on the macrophyte/habitat relationship.