Divide et disperda: Thirty years of fragmentation and impacts on the eco-mosaic in the case study of the metropolitan city of Naples

Nowadays, anthropic pressures are continuously transforming the landscape mosaic, leading to issues related to habitat fragmentation and the loss of ecosystem functions. In this study, a landscape-change analysis over the 1990–2018 timeframe of the case study area of Metropolitan City of Naples (MCN) (southern Italy) was performed to evaluate trends, causes, and results of the landscape transformations. We preliminary performed a spatial–temporal fragmentation-expansion analysis in the MCN through the landscape expansion index (LEI), and subsequently determined the impacts on the eco-mosaic. The multitemporal analysis (1990–2018) highlighted an urban expansion in the MCN. The LEI analysis depicted a dual tendency in the increased fragmenting of the MCN’s eco-mosaic. The urban landscape has compacted in the hollow areas, and in the meantime there has been a sprawling expansion of the urban fabric. The most impacted land-use category was “Agricultural areas”, of which 57.42 km2 have been lost in 28 years, with negative impacts on ecological connectivity. Finally, we investigated the relationship between the increase and type of landscape fragmentation and the demographic flows over time. We found that the areas affected by demographic growth were the same ones characterized by an edge expansion of the urban patterns. Conversely, where there has been a demographic decrease, an infilling behavior of urban fabric has been noted. This study highlights a possible correlation between the expansion type of the urban fabric and the demographic flows in a region as a main driver. The outcome of 30-year transformations is the actual ecological network in which Core Areas, Buffer Zones, and Primary Connections covered 35.3%, 11.1%, and 39.6%, respectively, of the total surface of the MCN, covering an overall area of 1008.4 km2.