Each area is globally unique in its composition of climate, soils, flora, and fauna. Also globally unique is the expansion history of the beech. It begins 12,000 years ago, at the end of the last glacial period. A process that continues on to this day.
UNESCO regards this as globally unique and of great importance. This outstanding universal value is the reason for the inclusion of the most valuable European beech forest areas on the World Heritage List.
They are “outstanding examples of significant ongoing ecological and biological processes in the evolution and development of terrestrial ecosystems and communities of plants and animals.” (criterion ix of the World Heritage Convention)