STUDY OF PHYTOSOCIOLOGY AND ECOLOGY OF AILANTHUS ALTISSIMA (MILLER) SWINGLE – INVASIVE SPECIES IN THE SOUTH-WESTERN OF ROMANIA

The intensive abiotic activity, but not only that, has brought about the invasion of allochtone (non-native) species in the natural and semi-natural degraded ecosystems in our country (M. Niculescu, 2011). Ailanthus altissima (Miller) Swingle, coming from China, is cultivated for decorative purposes in our country, but it also grows subspontaneously in the degraded and sunny fields. We can see it in the in the study area or this paper, in the South-Western of Romania. This species edified the plant community Balloto nigrae-Ailanthetum altissime Sîrbu and Oprea 2011 described first time in Moldova and identified in this area but with a slightly different floristic composition. Areas of Ailanthus altissima have greatly expanded in recent years across the country. This species grows explosively edifying plant community well defined and stable. Ailanthus altissima is adaptable to a very wide range of soil conditions and pH values and we found it within a wide range of climatic conditions. Species installs very quickly, is very lively and has a very high growth rate. We find this invasive species in the forest habitats and in the meadows, but also in the public parks, gardens, besides buildings and and roadsides. This species influence the succesional dynamics and the floristic composition of the forest plant communities, occupying increasingly more and more space