The study area related to the Apuan Alps, covering 1,056 km², is mostly located in the provinces of Lucca and Massa-Carrara in the northwestern part of Tuscany. It also includes the 9 Operational Geographic Units (OGUs) used as reference points in the research: Apuan portion of middle Lunigiana, Massa-Carrara, Tuscany (a), Apuan portion of coastal Lunigiana, La Spezia/Liguria and Massa-Carrara/Tuscany (b), hills and mountains above Carrara, Massa-Carrara, Tuscany (c), hills and mountains above Massa, Massa-Carrara, Tuscany (d), hills and mountains above Versilia, Lucca, Tuscany (e), coastal hills and mountains of southern Apuan Alps, Lucca/Pisa, Tuscany (f), Apuan portion of the hills and mountains above Lucca, Tuscany (g), Apuan portion of lower Garfagnana, Lucca, Tuscany (h), Apuan portion of higher Garfagnana, Lucca, Tuscany (i).