Human footprint into the woodland of Bosco della Foresta (Trapani Mountains, N-W Sicily)

Abstract

The Bosco della Foresta, currently also called Bosco di Angimbè or Bosco di Calatafimi, covers 210,90 hectares and is located on a complex of hills, referred to Cozzo Terravecchia formation (Miocene), north-east of the village of Calatafimi. The first documentary mention of this woodland dates back to AD 1393 in the municipal Diploma of Graces and Privileges (Diploma di Grazie e Privilegi) granted by the Counts of Peralta to the community of Calatafimi. The Diploma enshrines the civic right to cut trees to make plows and other farming uses, and the license to the poor to fetch twigs, without touching trees if not some dry branches, during Christmas, Carnival and Easter time. Since the eighteenth century, the forest area has shrinked. In 1846, the documents regarding a dispute between Prince of Ficarazzi and the Common of Calatafimi over the rights of civic use prove that the woodland included much more districts in comparison with present-day situation. Like every other Sicilian forest, the surface of semi-natural and natural systems (grasslands, shrublands, maquis, woodlands) in Calatafimi reached the peak of reduction during the early twentieth century, as shown in the analysis of the 1939 and 1955 aerial photographs. In recent decades, the gradual abandonment of marginal zones has reactived ecological succession processes, after the crop intensification started with the postwar Agrarian Reform and the development of mechanised agriculture during the Seventies. Currently, forest cover consists mainly of cork oaks (Quercus suber) and downy oaks (Quercus pubescens s.l.). The extension of Erica arborea shrub formations and Ampelodesmos mauritanicus grasslands is a clear indication of the continuous passage of fire. Overall, the landscape is characterized by high biodiversity both in floristic and phytocoenotic terms. A phytosociological study of plant communities has been performed to evaluate human- induced forest landscape changes in Calatafimi. The vegetation is, in fact, an accurate indicator of both the environmental characteristics of an ecosystem and the human activities that have formed and transformed the landscape. The vegetation analysis is carried out through the dynamic-catenal phytosociology methods in order to identify Land Units and the related vegetation series. Vegetation series are the result of the relationship between landscape natural heterogeneity and heterogeneity produced by humans through historical land use. Management and exploitation methods of forest resources are investigated using dendrometry and structural analysis of tree components. The absence of old-growth trees and the coppicing of woodland indicate a constant exploitation of the forest until the early decades of the last century. However, the diachronic comparison of historical aerial photographs has demonstrated a slow process of resilience and an increase in coverage values of tree layers and of surfaces covered by shrub vegetation.