The presence of mugo pines on the mountains of the upper Nure Valley is the result of the last Glacial Age (Wurm), the only one to have affected the Apennines of Piacenza.
As the mountain pine is a plant typically found in areas with a cold climate, at the apex of the Glacial Age it was found on the Alps, the Pre-Alps, and all along the chain of the Apennines as far south as Campania.
With the withdrawal of the ice sheets and the warming up of the climate, this plant spread up on to the summits of the mountains, where it could still find ideal conditions for survival.
Woods of mountain pines (mugheto in Italian) are found on Monte Nero, on the saddle of the Costazza and on Monte Ragola, especially on the southern slopes.
Gravel screes, unattractive to other species of trees, are the typical habitat of the mountain pine. In fact, the mugo pine grows in cracks between rocks, where it is tightly anchored thanks to its robust roots.