Designing with spontaneity: the return to nature in the contemporary city. Biodiversity networks and adaptive landscapes in Eastern Rome

This paper proposes the "return-to-nature" as an operational design framework for integrating spontaneous habitats and informal green areas into contemporary urban landscapes. Using spatial analysis, field observations, and open-access ecological datasets, the study examines three sites in Eastern Rome-Ex Snia Viscosa, Parco della Serenissima, and the ZSC "Travertini Acque Albule"-to evaluate how low-maintenance, process-based landscapes can contribute to biodiversity networks and climate adaptation. The results reveal recurrent patterns, including the ecological value of unmanaged areas, the interaction between cultural heritage and spontaneous vegetation, and inconsistencies between formal protection boundaries and actual habitat distribution. Based on these findings, six operational principles are defined: access by least impact, differential maintenance, succession windows, interpretive minimalism, co-stewardship, and adaptive monitoring. The study also advances the idea of a Rome-Tivoli Greenway as a transferable Mediterranean model capable of applying these principles at a territorial scale. The findings show that spontaneous urban nature can function as ecological infrastructure, support community stewardship, and reduce management costs, while also presenting risks such as invasive species dynamics and potential conflicts over access. The paper concludes with policy mechanisms-adaptive maintenance regimes, stewardship agreements, and updated planning tools-to operationalise the proposed approach and support more resilient and biodiverse urban landscapes. Overall, the "return-to-nature" framework provides a transferable approach for cities seeking to enhance biodiversity, resilience, and socio-ecological integration through lighter and more adaptive design strategies.