Appropriate adaptation to new environmental conditions requires scientific research on the action of climate change on forest ecosystems and, in particular, on valuable indigenous species (such as oaks). This study presents the response of forest ecosystems to the phenomenon of climate aridization by calculating and mapping the Ellenberg coefficient (EQ), with the determination of areas favorable for the growth of certain types of forests, with emphasis on the Central European deciduous mesophilic forests, located on the South-East border of its natural area in the Republic of Moldova. The dry years will lead to the reduction of mesophilous forests (beech stands - EQ≤20; stands with Quercus petraea and Q. robur - EQ=20-40) in favor of thermophilic/dry forests with Quercus pubescens (EQ≥40) from South of country. The temporal analysis of this index (1961-2016) shows that in the near future, under the influence of climate change, EQ values will increase, the southern region of the country experiencing the most severe impact of aridization (the Northern part EQ = 33,2, the center of the country EQ = 41.0; Southern part EQ = 43.0).