Beech is a dominant forest tree species of high economic as well as ecological importance with a wide distribution range línking Scandinavia and the Mediterranean. Due to its functional flexibility and large genetic plasticity, beech can be utilized to study wide reaching influences affecting ecosystems.,, e.g. climate factors in different parts of Europe. The COST Action E52 "Evaluation of Beech Genetic Resources for Sustainable Forestry" commenced March 2006. During the final meeting of this COST action (Burgos, Spain, 4th to 6111 of May, 201O) results of numerous research areas were presented, of which a special selection Is published here. Among them, the evaluation of data from provenance trials located In most of the regions of beech occurrence show how well populations have adapted to certain site-inherent environmental features, e.g. limited water availability , late frost occurrence, acidic or calcareous soil, as well as how non-adapted populations react to such situations ,and how successfully they might cope with them. This is of great significance for assessing the value of both, a given beech population and its ecosystem with respect to the conservation of beech ecosystems in a broad sense and particularly the genetic resources of beech.