Urban biodiversity and social inequalities in built-up cities: New evidences, next questions. The example of Paris, France

► Mean household incomes vary in presence of planned and unplanned urban green. ► Floral richness, ecological diversity and density are not correlated to household incomes. ► There is a relation between semi-natural spaces, landscapes and household profiles. ► Ecosystem services benefit more middle and working-class households than well-off ones. ► These finding are significant for putting Paris Biodiversity Plan in place. The preservation of biodiversity, city-dwellers’ quality of life and equality are major issues in promoting sustainable cities. We chose to work at the built-up and much-valued heart of an agglomeration: Paris. We attempt to verify whether public semi-natural spaces with spontaneous vegetation and green frames provide ecosystem services to city-dwellers in an equitable way, and what is the role played by urban landscapes in this relation. Based upon existing datasets, a spatial and statistical analysis of relationships between public semi-natural spaces, urban landscapes and socioeconomic profiles of households was carried out. We compare their spatial patterns, which vary considerably. Mean income per vegetal and landscape cluster and correlations between income, ecological parameters and building density show complex and non-linear relationships. According to Multiple Correspondence Analysis, clusters of public semi-natural spaces, floristic richness and ecological diversity are associated with specific household socioeconomic profiles and landscape design. In the western built-up Haussmann districts inhabited by well-off households, public seminatural spaces provide low ecosystem services. Conversely, in the eastern and peripheral quarters where lower-income households live, public semi-natural spaces provide higher ecosystem services. It is not only well-off households which benefit from being close to urban parks and waterways. Blue and green frames cross districts inhabited by different household profiles. The implications of such results on inequalities between city-dwellers depends whether the presence of public semi-natural spaces actually improves their quality of life. These results are highly significant at a time when urban planners are putting the city's Biodiversity Plan in place.