Through time

The last glaciation caused significant shifts in the forest vegetation of southern Italy. During glacial peaks, the coniferous forest reached sea level, while during temperate interglacial periods the mixed oak forest dominated.  During the post-glacial period (which began about 11,700 years ago), the distribution of the deciduous oak forests underwent several shifts in response to changes in climate. Oaks became a more or less stable presence in a middle submontane belt, between the montane belt dominated by beech and silver fir, and the Mediterranean evergreen belt. Climate-induced contractions and expansions during the postglacial period are said to explain some of the characteristics of present-day oak forests. For example, the frequent replacement of mesic oak species (Quercus robur and Q. petraea) by Q. pubescens and Q. cerris. The latter are more plastic and able to spread in the Mediterranean (Q. pubescens) and in the montane belt (Q. cerris). The widespread presence of Q. cerris in the lower part of the montane belt is favored by edaphic factors, such as clay soils, to which this species is well adapted [1].

In historical times, over the centuries, the deciduous oak forests in the submontane belt were drastically reduced by human cutting, agriculture and grazing. Many documents and toponyms refer to places where oaks are absent or sporadic today. Over the centuries, oak forests were intensively used to supply the shipyards. In unified Italy, the increasing need for agricultural land due to population growth and the demand for railway sleepers were among the most important factors causing the reduction of oak forests. In southern Italy, many areas once covered by oak forests have been cleared, and the remaining forests have been severely fragmented. 

Southern inland areas (the case of Basilicata)

Forests dominated by Quercus cerris represent the natural forest vegetation at altitudes between 500 and 1200 m in many inland areas. In Basilicata, up to an altitude of about 1000 m, Turkey oak is mixed with other tree species such as maple and hornbeam. In the undergrowth there is often a dense layer of shrubs of shade-tolerant species (ivy, butcher's broom, privet, daphne, holly). Higher up, the oak forest gives way to the montane beech forest, with species such as maple, sycamore, and Lobel's maple. In warmer places, a more xeric forest develops, in which the turkey oak is associated with the Hungarian oak (Quercus frainetto) and the downy oak (Quercus pubescens). A shrubby understory is often found here (wild rose, Cytisus sp., hawthorn, blackthorn, Lonicera sp., etc.).  

Even-aged stands with a mono-layer canopy predominate. In several cases these stands are the result of cuts made to transform coppice stands into high forest stands. Bi-layered stands occur where oaks dominate a hornbeam layer. Coppice stands are often beyond the age of traditional rotation ("aged" coppice stands). In many cases, oak stands are heavily grazed.