SUMMARY

Foresttree species populations are characterized by broad genetic variation both on the molecular level and the level of adaptive traits. The predicted climate change is foreseen to have an impact on the Mediterranean ecosystems, as both temperature and drought are expected to rise, while extreme climatic events will occur more frequently. Constant human impact on forest ecosystems and thus, on forest genetic resources has been recorded ever since the prehistoric times. Nowadays, human impact can stem from a)artificial selection and genetic improvement of forest tree species, b) transfer of genetic material, c) forest management methods, and d) environmental changes. Results of the research revealed that artificial selection and breeding of forest tree species result in an increase rather than  decrease of the species genetic variation. Transfer of genetic material may have an impact on forest genetic resources. Two aspects should be considered: the impact of transplantation on the resource transferred in an new environment and the impact on local genetic resources. Moreover, different sylvicultural practices may affect the genetic variation of a species by changing the demographic parameters.  Forestmanagement may also influence the speed of adaptation of forest tree species to climate change. Consequently the identification of criteria and indicators aiming towards the conservation of forest genetic resources is considered of vital importance. 

Keywords: forest genetic resources, climate change, plasticity, adaptation, transfer of genetic material, sustainable forestry, sylvicultural practices.