Arunco-Aceretum comprises forests of Acer pseudoplatanus and Fagus sylvatica with a herb layer containing the tall forbs Aruncus dioicus and Lunaria rediviva and various nutrient- and moisture-demanding forest herbs. These forests occur especially on the lower part of steep slopes, especially in shaded ravines. This association occurs across a broad range of altitudes, with most occurrences between 300 and 900 m.