Frammentazione e perdita di spazi aperti nelle metropoli mediterranee: indici e metriche del paesaggio quali strumenti di analisi e per la valutazione di scenari di pianificazione resiliente

This thesis highlights the relevance of the landscape ecology analysis as a tool for planning the resilience of the metropolitan areas in relation to the processes of loss and fragmentation that are impacting on the open spaces. The research is focused on the Mediterranean region where an ever-growing alteration and fragmentation of the natural and semi-natural environments, as consequence of rapid urban and infrastructural expansions, is observable at multiple scales. For this reason, the thesis supports two main hypotheses: namely that planners should led more effective plans of resilience to the abovementioned processes monitoring the evolution of the metropolitan landscapes through several metrics and indices provided by the discipline of the landscape ecology; nevertheless, these analytical tools should be part of more integrated analysis with the aim of sustaining or restore the landscape services, on which all the species depend. The work is divided in four chapters as explained below. Firstly, a bibliographic recognition of the historical trajectories that have generated the metropolitan and the post-metropolitan forms is proposed. In order to debate the ways to resolve the socio-ecological critical points emerging from the model of unlimited growth that have guided their evolution, several alternative models (such as socio-metabolic models and bioregional approaches) are taken into account. The second chapter illustrates (i) some basic European directives concerning environmental conservation, (ii) some examples of green infrastructure’s planning and (iii) some case studies of urban and peri-urban agriculture in the Mediterranean region. The third chapter takes into account the potentials and the practical opportunities provided by landscape metrics and indices for the analysis of the processes of fragmentation and loss of the open spaces. Several research approaches (es. MuSIASEM or Energy-Territory Integrated Analysis) are illustrated and the case of the metropolitan urban planning of Barcelona is presented. Finally, in the fourth chapter, an original explorative analysis of the recent dynamics of lost and fragmentation interesting the metropolitan areas in the Mediterranean bioregion is presented. The study was carried out considering the CLC land use data in a multi-temporal perspective (1990-2012), through the elaboration of a set of metrics and indices referred to a representative number (97) of metropolitan areas. This set was employed for several objectives: to evaluate the urban and infrastructural expansion’s features; to identify examples of landscape fragmentation impacting on the ecological connectivity; to illustrate the recent loss of landscape functions; and, finally, to develop a proposal of a GIS-based method allowing the identification of critical areas needing priority -and multi-disciplinary- intervention with the aim of supporting and restoring the landscape ecological functionality.