Invasive plants inhibit the development of the diverse flora and fauna typical of oak forests. For this reason, DINPD has started to suppress black locust, ailanthus, common hackberry and 15 other invasive and alien plants on a total of 30 hectares across five project sites. The goal is to create on a long term native forests and forests-grassland patches. On a long term we create space for the regeneration of the native oak forests and forest-grasslands patches in Fóti-Somlyó and Sas-hegy by the injection and the chemical stump-cut treatment of invasive species. In contrast to the infected areas where only 40-50 insects or plant species can be found, native forests hosts up to 500-600 insects or plant species per hectare.