Floristic and vegetational characterization of degraded areas in the province of Pisa: the case of a dismissed quarry and the neighboring territory (Municipality of Vecchiano)

The natural restoration of abandoned mining areas is one of the most complex environmental challenges due to the multiplicity of issues involved. In general, the spontaneous dynamics of renaturation in the quarry areas are very slow and altered because of limiting environmental conditions. So, recovery actions should promote ecological processes interrupted by mining and then the acceleration of the natural dynamics. Presently, in the province of Pisa several abandoned quarries have not undergone the necessary environmental recovery and, for this reason, they are classified as "areas of geophysical degradation". These include the former quarry C.E.I. dismissed in 1992 and located on the Monti d’Oltre Serchio in the municipality of Vecchiano (PI). The present work was focused on the flora and vegetation of this area. The study area, including the quarry (2.9 ha), the remaining sides of the Poggio dei Cavoli and the adjacent ridge of "Sassi Grossi", is characterized by limestone formations of the non metamorphic Tuscan Falda. It is characterized by a rather hard carsism, with almost no soil and high pH in the quarry area, while it is rich in oxides and lacking humus in the outer portions. Inside the cave, however, the scarcity of vegetation cover and the strong albedo, due to the light-colored rock, cause a different microclimate, characterized by dryness and higher temperature. The flora consists of more than 200 vascular species, of which about 50 are restricted to the quarry and 85 to adjacent areas. Particularly important is the number of floristic emergences, including rare orchids and ferns, which induced some scientists to propose the inclusion of the study area within the Regional Park of Migliarino-San Rossore-Massaciuccoli. This makes the site interesting from an environmental perspective and therefore, worthy of further valorisation and protection. The analysis of aerial photographs and surveys conducted in the field has allowed the identification of the main types of vegetation (Fig. 1). In the territory outside the extraction site, the Mediterranean Macchia (high, medium and low) with evergreen sclerophyllous (Quercion ilicis) in catenal contact with the Garrigue (Rosmarinetalia officinalis and Thero-Brachypodietalia), and the mixed forest with dominant oak and transitional pruneto (referable to the alliance Quercion pubescentis- petraeae Br. Bl. 1931), can be found. The quarry area is, instead, dominated by a pioneer vegetation that is hygrophile on the plain of the quarry, and lithophile on the front. This latter, at least in part, has species in common with the surrounding garrigues. This is interpreted as the initial stage of the series of vegetation that should lead to the reconstitution of the original forest cover, represented by the actual vegetation of the adjacent areas. The widespread presence of species such as Rubus ulmifolius, Clematis vitalba and Dittrichia viscosa (L.) Greuter, and of invasive exotic species, such as Cortaderia selloana, Robinia pseudoacacia, Buddleja davidii and Ailanthus altissima, reveal that, without proper action, it is difficult to imagine a fast around the quarry.