M. Dubas! : Deserti fication of Mediterranean and Mountainous Regions
191
Figure 3. Hydrological shifts after a climate change for the European countries (Brouwer and
Falkenmark, 1989).
In some sense, the abandonment of ancient agricultural or pastoral lands is a
recovering process, recreating forest or semi-natural landscape, where natural fires
could contribute, to some extent, to the regeneration of ecosystems and maintenance of bio-diversity at the landscape level.
However, the high-frequency of forest fires in many Mediterranean regions, by
pure negligence or actual voluntary actions, produces wide-spread and serious
degradations in the environment.
In the South, for opposite reasons, mainly relating to demographic pressure, with a
parallel and dramatic increase of stocking densities and consumption of wood for
domestic purposes, the environment is also undergoing severe degradation
processes . This is jeopardizing the future of many mountain communities,
particularly in the mountain areas of the North-African countries.
Statistical data available to compare the evolution of the forests and arable lands
among countries of the Mediterranean basin provide good evidence of these two
very opposite trends in the North and the South (see Table 2, Quezel, 1956).