Mapping the urban landscape at multiple ecological scales

Urbanization is increasing worldwide, driving the expansion of urban areas and resulting in habitat loss, fragmentation, and changes in environmental conditions. Despite these pressures, urban landscapes can still support biodiversity, provide essential ecosystem services and contribute to conservation. Several metrics exist to characterize landscapes, but the spatial scale at which they are relevant depends on species ecology or on the ecological process of interest. Rome, one of Europe's oldest cities, has experienced continuous urbanization over centuries while maintaining a remarkable level of greenery. This study explores the landscape structure in Rome using a multi-scale approach. We analyze key landscape metrics—Green Area Proportion, Edge Density, Shannon Diversity Index, and Edge Distance—across four spatial scales (10 m, 50 m, 250 m, and 1250 m), which are relevant for the ecology of a wide variety of plant and animal organisms that occur in the city. We show that these landscape metrics can be summarized by two major axes representing urbanization and fragmentation, respectively, and allow for grouping Rome green areas into three types (homogeneous green areas, highly impervious areas, and impervious surfaces interspersed with small green spaces). The high-resolution raster data generated in this study can lay the foundation to test how these axes at different scales and theresulting landscape types can shape urban species assemblages