Beyond the urban-rural gradient. Self-organizing map detects the nine landscape types of the city of Rome

This paper analyses the distribution patterns of Rome's spontaneous flora, based on published atlas of species distribution in a grid format. The use of Self-Organizing Map (SOM) makes it possible to recognise and clearly define nine different ecological groups of grid-cells, corresponding to nine different landscape types. The landscape types are characterised by sets of diagnostic species, which are characteristics of the natural environment (soil, climate) and history of urbanisation. This pattern runs counter to the traditional urban-rural gradient, which is the general model of the towns in the Global North; instead it is closer to the still poorly studied towns of the Global South, where urban development is chaotic and unplanned, resulting in a complex urban mosaic of patches with different history and land-use.