One size does not fit all: A tale of polycentric development and land degradation in Italy

Abstract

Polycentric development is one of the fundamental components of the European Spatial Planning and Development (ESPD) strategy and substantiates the legitimacy of a decentralized governance framework. Spatial planning in polycentric regions has often been found to be ineffective in achieving a truly sustainable development. Relatively few studies have explored the nature of the relationship between polycentric development and the increasing sensitivity of Mediterranean landscapes to desertification. This knowledge gap is somewhat surprising given that economic development has often been considered to be a driver of land degradation. Italian socioeconomic and territorial variables were investigated to determine if levels of land sensitivity to desertification (measured using a composite indicator) had increased more rapidly in mono-centric or polycentric systems. Distinctive settlement models have epitomized the spatio-temporal evolution of the composite indicator for the last 50 years. The first model, from the early 1960s to the early 1990s, reflects a spatially centralized and functionally mono-centric development with density, concentration, and agglomeration acting as key factors of change. Local systems with a purely mono-centric structure exhibited increasing levels of land sensitivity. The increase in land sensitivity from the early 1990s to the early 2010s, was spatially decentralized and mostly dependent on place-specific dynamics. Local systems reorganized themselves on the basis of individualized development models, attempting highly differentiated and poorly coordinated development paths. This study documents how the evolution toward spatially balanced polycentric models can mitigate the growth of land sensitivity in specific contexts. Managing transitions towards polycentric models with positive environmental implications calls for a proactive analysis of the background context, a clarification of socio-economic constraints and spatial limits to centralized and/or decentralized development processes.