Expressing the vulnerability of forests to climate aridization by ecoclimatic indices (case study)

Climate change is associated with numerous and complex adverse effects on environmental components, including on forest ecosystems (especially for those within the natural distribution area). Expression of the forest ecosystems vulnerability to climate aridization, takes into account various ecoclimatic indices such as: Forest Aridity Index, De Martonne Index and Ellenberg Quotient, developed on the climatic parameters values specific for the tree active vegetation period. The results of the research indicated the fact that the Hârbovăț forest ecosystem is subjected to a high level of forest vulnerability to droughts (IM values between 25.0-28.8) with tendencies towards a very high level of vulnerability, with a long-term deficit in humidity, disturbances that can lead to adverse effects on the growth and development of mesophilic forests in the region, until the marked decrease of their area; EQ values identify specific climatic conditions for the development of the mesophilic deciduous forests from the temperate zone, but which, in the near future, under the influence of climate aridization, will change to specific climatic conditions for the growth and development of arid oak forests; and the FAI values – that during the growth period and the „critical” period of the forest species (July, August), the climatic parameters indicate drier and more arid conditions for the development of the oaks stands, therefore, more favorable to the development of the Quercus pubescens species, than the Quercus robur and Q. petraea species. Concerns about the impact of climate change on native tree species, must be a constant in the country’s sectoral priorities. The results of the study, in addition to the de-facto assessment of the situation in the researcharea, also indicate particular climatic trends for the growth and development of trees in the future, in the context of environmental changes.