Mediterranean landscape changes: evidence from old postcards

Recent, rapid and often underestimated landscape changes have occurred over large areas in Mediterranean Europe. They are the result of major rural de population. Old photographs of landscapes taken at the beginning of the twe ntieth century (i.e. old postcards) and present-day photographs taken at th e same places were compared in a 2500-km(2) area of southern France. Vegeta tion changes were analysed using transition matrices. During the 80-year st udy period, land uses and vegetation changed dramatically Woodland cover an d tree height increased; but in contrast, the extent of cropped lands and r angelands decreased. Forest spread was heterogeneous, depending on initial composition of the vegetation, and locally dominant ecological and socio-ec onomic conditions. Our data show that a Mediterranean forest can re-establi sh under humid climatic conditions and spread within a century, despite sev ere prior exploitation over several decades. These dramatic changes are lia ble to have biological and ecological consequences (e.g, spread of woodland species, threat against open habitat species, fire regime modification, de terioration in water resources), some of them being already perceptible.