Landscape change and the dynamics of open formations in a natural reserve

Remote sensing, when used in conjunction with landscape pattern metrics, is a powerful method for the study of ecological dynamics at the landscape scale by means of multi-temporal analysis. In this paper, we examine temporal change in open formations in the natural reserve of Poggio all’Olmo (central Italy). This area has undergone rural depopulation and the cessation of traditional methods of agriculture, resulting in the subsequent re-establishment and spread of other vegetation formations. Aerial photographs taken in 1954, 1977 and 1998 were orthorectified and classified based on the physiognomic characteristics of the vegetation. An objective definition of the minimum mapping unit (MMU) was guaranteed by using vector format grids for this classification. We applied landscape pattern metrics based on landscape composition, the shape and size of patches and patch isolation. Our results demonstrate the key roles of shrubland, woodland and coniferous plantations in the ongoing fragmentation of open formations in the landscape. Multi-temporal landscape analyses, and, in particular, a restricted suite of landscape metrics, proved useful for detecting and quantitatively characterizing dynamic ecological processes. We conclude with some recommendations on the management alternatives feasible for the protection of the remaining grassland formations in the natural reserve of Poggio all’Olmo.