Species richness in 10 m2-plots for different taxonomic groups compared at different syntaxonomic levels. Box plots (median, interquartile range, range and outliers) as well as arithmetic means (black points) are shown. For the codes of syntaxa, see Table 1. Different letters within one syntaxonomic level indicate significant differences at p < 0.05 according to Tukey’s test following a significant ANOVA. For orders, the two-digit codes after the slashes and the letters below the boxplots apply.