INVASIVE SPECIES - THEIR IMPACT ON THE ECOSYSTEM. CASE STUDY: TARGOVISTE PLAIN

Invasive species have a negative effect on the habitats they invade - economically, ecologically, or in point of landscape. The invasive phenomenon occurs especially in the habitats where competition is weak or weakened through man's intervention. The area under analysis includes the piedmont Plain of Targoviste (in the Romanian Plain, the Plain of Targoviste has a peripheral position, being limited in the south, south-west and south-east by the subsidence Plain of Titu-Salcuta and in the east by the piedmont Plain of Cricovul Dulce. Limited by two major physical-geographic units (Subcarpathians, Getic Plateau), the Plain of Targoviste has benefited of the natural and human resources supplied by these two units, and by the presence of Ialomita and Dambovita River; from an administrative perspective, the Plain of Targoviste is completely included in Dambovita County - its central-south area. The limits considered as interference areas where the morphological features of the units coming together combine, define the plain as a set of forms of relief with different altitudes and development. The geographic position has favored the appearance and development of human settlements). The last few years have witnessed the development of invasive plants - in reaction to the recent ecological problems, such as: climatic variations, changes in land use, habitat fragmentation - which has influenced the variability of the land structures and functions. The consequences of the landscape fragmentation are negative for the environment when this fragmentation is given by changes of the land use. In the area under analysis, 8 invasive species have been identified, with an impact on the whole ecosystem.