Chelidonio-Robinietum is an association of mesic woodlands dominated by Robinia pseudoacacia. Sambucus nigra usually occurs in the shrub layer. The herb layer is dominated by tall nutrient-demanding species, as well as species of the herb layer of the original native forest types. This association occurs in habitats of former ravine forests, oak-hornbeam forests and mesic types of thermophilous oak forests, both in forested and agricultural landscapes as well as in human settlements. While many stands were planted for wood production or erosion protection, others established spontaneously, either generatively or vegetatively.