The alliance Aegopodio-Sambucion includes mesophilous and xerophilous shrub vegetation with significant participation of nutrient-demanding and alien species. Besides Sambucus nigra, dominant species of this vegetation include aliens such as Acer negundo, Lycium barbarum, Symphoricarpos albus and Syringa vulgaris. The herb layer is characterized by dominance of ruderal species of both native and alien origin. Several associations dominated by alien shrub species could be distinguished within this alliance, but we recognize only those that are the most common, established for a long time and have developed distinctive habitat affinities in central Europe.