You don't have to get very far from the shores of the Med to find oak groves.
This is what you find in Liguria: "On the Mediterranean coast there are palm trees, lemons, oranges, bougainville, oleander, hibiscus, red gillyflowers, bluebells, agaves, myrtle, wild lavender, thyme and other local flowers which only exist in this area. In the rolling hills of the hinterland, you will find silvery green olive groves, vineyards, broom, hyacinths, orchids, pine trees, oak trees, fig trees, eucalyptus, sage, gentian and lilies. And going yet higher up into the alpine region, there is dense forestland with chestnut trees, birch trees and oak trees."
http://www.terra-italia.com/en/riviera-liguria/flora-and-fauna/
In good times, the acorns are fed to the pigs, but Liguria, alta Toscana and the Apennines are marked by very poor mountainous terrain. Even wheat doesn't grow very well in certain areas, so wheat flour sometimes had to be imported. Peasants ate bread from chestnut flour (chestnut trees are ubiquitous in mountainous areas in Italy) or mixed chestnut flour and wheat flour, and in starvation times acorn flour as well.
The "Panigacci" of this area, which are round pieces of unleavened flat bread cooked in ceramic (terracotta) forms heated in an open fire, are now made with wheat four, but during the war, people often made them from a mixture of chestnut and acorn flour.
http://mangiarebuono.it/i-panigacci-della-lunigiana/
Ed. They mean the Apennines when they speak of the Alps, not the Alps between Switzerland and Italy. If you've ever looked at a map of Italy, most of it is mountainous.
Hazelnut trees are also ubiquitous. Many Italian sweets are made with hazelnuts, almonds, or both.