Urban ecosystems’ fragmentation as an ecological measure of urbanization quality in shrinking cities

Urbanization quality assessment requires a multidimensional approach encompassing socioeconomic, spatial, environmental, and governance factors. However, existing methodologies often overlook ecological implications—an aspect particularly vital in shrinking cities with a high proportion of areas covered by vegetation and water. This study examines the impact of socioeconomic changes and two planning system transformations on urban ecosystem fragmentation in post-socialist Poland, focusing on four medium-sized cities in the Mazowieckie Voivodeship. A novel assessment framework is tested that integrates ecosystem fragmentation as a measure of urban natural system (UNS) structure, order, and distribution. The methodology includes satellite data extraction, supervised classification, land cover change analysis, spatiotemporal fragmentation assessment, and analysis of relationships between urban demographic trends and ecosystem fragmentation to identify patterns of uncontrolled urbanization. An urbanization quality assessment is provided. The findings reveal that, despite demographic decline, urban expansion persisted, intensifying ecosystem fragmentation. Urbanization occurred both within and beyond areas covered by Local Development Plans, exposing weaknesses in planning instruments and urban ecosystem policies. Croplands and grasslands emerged as the most vulnerable to fragmentation. Incorporating ecosystem fragmentation into the urbanization quality evaluation procedure significantly influenced assessment outcomes. The results indicate that shrinking cities failed to capitalize on population decline by developing coherent urban ecosystem networks. Instead, spatial chaos persisted, suggesting that EU accession and planning reforms did not effectively mitigate the negative consequences of neoliberal urbanization. The proposed framework enhances urbanization quality assessment by integrating ecosystem fragmentation and offers a globally applicable tool for sustainable urban planning.