Adventive species are found countrywide in Romania and significant efforts are necessary to prevent them from becoming an aggression even to reservations. In the perimeters in which invasive species have spread, extraction works were necessary to the purpose of containing them under 5%. Species such as Ambrosia artemisiifolia, Amorpha fruticosa, Carpinus betulus, Crataegus monogyna, Helianthus tuberosus, Phytolaca americana, Reynoutria bohemica, Robinia pseudacacia, Rubus caesius end Sambucus ebulus have been extracted. Even so, the balance of the abiotic and biotic parameters of the affected areas is relatively delicate.