A old-growth forest is an ecosystem characterised by the presence of mature trees, which may therefore be at the end of their life cycle. Old-growth forests represent the highest expression of naturalness in our territories. In fact, thanks to the absence of human action, the trees manage to complete their entire life cycle until death, thus reaching the maximum possible age to which, in fertile places, considerable dimensions are associated.
An old-growth forest is a dynamic system in which plants grow, reproduce and die a "natural death", competing for resources, but also cooperating with each other. In an old-growth forest, several generations of trees with centuries-old age differences may be in close contact with each other in places where moribund, centuries-old trees are close to young seedlings.
On the whole, the old-growth forest shows a particularly articulated structure in which trees of various sizes and seedlings mingle in space in an apparently chaotic manner. When analysing the history of old trees, however, one discovers that over the centuries they have gone through the four phases that make up the structural cycle. The duration of a complete cycle can vary on average between 300-500 years.

The Cozzo Ferriero beech forest covers an area of about 70 hectares and is almost flat at about 1,700 metres. In this area there are monumental beeches that are over 400 years old, trees of various sizes and dead stems still standing and on the ground - typical of beech forests - that the long absence of human activities has preserved, resulting in a complex forest rich in biodiversity.

The Pollinello beech forest grows in a unique territorial context between the Pollino and Dolcedorme peaks, in symbiosis with the centuries-old Pino Loricato, and extends up to an altitude of 2,000 m, thus managing to withstand quite extreme climatic and environmental conditions. In this beech forest, thanks to the collaboration between the University of Tuscia and the Pollino National Park Authority, the oldest beech trees in Europe dating back over 600 years have been discovered.

The World Heritage Committee approved the inclusion of Beech Forests in the World Heritage List considering as an evaluation criterion that "these complex and undisturbed temperate forests display the most complete and comprehensive ecological patterns and processes of pure and mixed stands of European beech through a variety of environmental conditions, such as climatic and geological conditions". He also pointed out that "beech is one of the most important elements of the Temperate Hardwood Forest Biome and represents an outstanding example of the recolonisation and development of terrestrial ecosystems and communities since the last Ice Age", and that "the dominance of beech in large areas of Europe is a living testimony to the tree's genetic adaptability".

After the last Ice Age, around 11,000 years ago, the beech tree from the small refuge areas of southern Europe began to expand northwards. During this expansion, which is unique and still ongoing, the beech tree has formed complex plant communities through the interplay of environmental and climatic diversity and the species' connatural characteristics. There fore these forests have generated a valuable ecosystem as they hold a genetic reservoir of beech trees and many other species that are connected to and dependent on these ancient forest habitats.
The Italian territory is the one that, after the Ukraine (no. 15), has the largest number of sites of ancient beech forests of exceptional universal value, each of which has been selected for its biological and ecological uniqueness, as a characterising element of an aspect of the continental network, whose overall ecological diversity constitutes the true heritage to be safeguarded.

The 13 recognised beech forests are unique in the whole contintent: in fact, our country has the oldest beech trees in Europe (600 years old), with a widespread heritage of ancient trees over 400-500 years old. Some of our beech forests, although they do not have the same spatial extent, equal in naturalness the primary beech forests of the Carpathians.

In addition, our country hosts the southernmost components of the new transnational serial site of the "Primordial Beech Forests of the Carpathians and other regions of Europe": a refuge zone where centuries-old trees have been able to adapt to climatic vicissitudes in areas that have been one of the most important glacial refuges for the species and that host unique genotypes, adapted to hot-arid climates, whose conservation is crucial for understanding adaptation to current climate change.

In this transnational network, alongside its natural value, the beech tree represents a species with a high symbolic and cultural value, historically linked to the development of the European peoples (the etymology of the name refers to the edible fruit, 'phagein' or 'eating' in Greek; in English and German 'beech' and 'buchen' refer to the word 'book'). The beech covers a large part of the European territory, thus becoming an ecosystem with a symbolic value for transnational environmental policies.
On a local level, the high symbolic, historical and cultural value of these forests is testified by the importance attached to them by the local populations, who have respected and preserved them even through less fortunate historical periods (e.g. two world wars) and climatic conditions, to the point of handing them down to us.

Reference sites
https://whc.unesco.org/en/list/1133/
https://www.faggetevetuste.it/
https://www.europeanbeechforests.org/world-heritage-beech-forests/italy/cozzo-ferriero
https://www.unesco.it/it/PatrimonioMondiale/Detail/481