These pine forests with Pinus sylvestris of north-eastern central and eastern Europe contain boreo-continental taiga species (including Vaccinium myrtillus and V. vitis-idaea) mixed with drought-adapted continental species typical of steppe grasslands. This makes their herb layer richer in species than that of the taiga pine forests belonging to the alliance Dicrano-Pinion sylvestris. Pine forests of the alliance Festuco-Pinion develop on slightly acidic or slightly basic substrates, mainly sand and sandstone.