Are Agrarian Areas in Mediterranean Mountain Regions Becoming Extinct? A Methodological Approach to Their Conservation

Mediterranean mountain regions have undergone several landscape changes since the end of the 19th century due to progressive depopulation and the abandonment of cattle rearing, forestry, charcoal production and agricultural activity. Such activity favored landscape dynamics by creating grassy habitats, which in turn resulted in greater landscape diversity. This is now being lost as the forest reclaims abandoned pastures. Thus, the purpose of this work was to identify those open habitats most in need of management action to maximize biodiversity and cultural heritage conservation and minimize fire risk and management costs. These analyses show a sharp decrease of open agriculture areas, which are the habitat of many endemic species (from 46.4% to 12.3%), currently overgrown with secondary forests. Multivariate analysis and the PGP (Patch Growing Process) heuristic model indicate the areas in which the restoration of open areas (by about 8%; about 500 ha) will be the most advisable and the most beneficial, taking into account environmental, social and economic factors. The use of PGP provides for a 21% improvement in total agriculture areas. Still, the natural state of the protected Mediterranean mountain area "Alta Garrotxa" (Catalonia, Spain) is almost continuous forest. However, the management models proposed in this study offer flexible precepts to achieve the desired landscape patterns and maintain biodiversity, while conserving cultural heritage and decreasing the risk of fire.