Beech forests are the end point of the spontaneous evolution of forests, forming climax vegetation in places that are neither too dry, nor too hot, nor too humid. If nature had its way, beech trees would cover most of our continent. Nearly natural old beech forests are now extremely rare in Europe and are usually found on sites that are difficult to cultivate or develop. In international comparison, the beech forest belongs to the European habitats that are significantly endangered, even though the beech as a species is not at all endangered. This is why the few primary and ancient European beech forests that have not been or have been little modified by man have been included in the UNESCO World Heritage List. This transboundary heritage comprises 94 elements spread across 18 countries.
Since the end of the last ice age, the European beech has spread from a few isolated refuge areas in the Alps, the Carpathians, the Dinarides, the Mediterranean and the Pyrenees, over a short period of a few thousand years, in a process that continues to this day. The successful expansion across an entire continent is linked to the tree's adaptability and tolerance to different climatic, geographical and physical conditions. These forests contain an invaluable population of old trees and a genetic reservoir of beeches and many other species, which are associated with and dependent on these ancient forest habitats.
Throughout the year and their life cycle, beech forests go through highly differentiated stages and processes: from germination to the growth of densely packed young trees in their first years, through decades of competition for space, water and light, to ageing into a large tree, followed by death and decay.
Please note that this information is a general description of the UNESCO World Heritage Site, which is located elsewhere in the Sonian Forest. In 2017, five parts (located in Ticton, Joseph Zwaenepoel and Grippensdelle) of the Sonian Forest were recognized as the UNESCO World Heritage Site of "Primeval and Ancient Beech Forests of the Carpathians and Other Regions of Europe". This is the only natural UNESCO World Heritage site in Belgium.