Analysis of urban ecosystem condition indicators for the large urban zones and city cores in EU : threshold assessment and exploration of the relation to ecosystem services through the application of G.I.S

Abstract: As almost three out of four EU citizens live in urban areas and this number is expected to further grow, studies on urban ecosystems and their services are crucial to understand a city’s environmental structure and capabilities. The European Commission has published a relative report which suggests an urban ecosystem condition indicator framework, yet without suggesting respective thresholds that might indicate a “desired” environmental condition of the city. The European Commission’s report also points up that the relation between the ecosystem condition and the ecosystem services still needs scientific underpinning. The current study estimates 8 (eight) of the suggested by the European Commission, urban ecosystem condition indicators, for 305 EU cities, suggests relative thresholds in Urban and Metropolitan spatial scales and explores their relation to ES and the Urban Heat Island effect. Furthermore, the intermediate zone is studied to assess its contribution to the overall GI and by extension the ecosystem services provided. The estimation of the indicators was mainly based on the processing of land use spatial data of 305 EU cities with population more than 100.000 inhabitants through the application of G.I.S. The assessment of the relative thresholds is based on the method of simple averaging of each estimated indicator values for territories in EU, defined on a case-by-case basis in relation to precipitation and temperature patterns through a cluster analysis. The estimated ecosystem condition indicators and respective thresholds have been visually and numerically juxtaposed to two (2) ecosystem service indicators and the Urban Heat Island effect to examine their relation. The study found a relation between the majority of the studied ecosystem condition indicators and the examined ecosystem services and the Urban Heat Island effect either at the one or at both the examined spatial levels. The study also found a significant differentiation between the examined indicators in urban and metropolitan scale while the intermediate zone that lies in between the two spatial levels presents a considerable contribution to the overall GI and by extension the provided ES, fact that is to be considered when implementing climate adaptation strategies. Another outcome of the study is the revealing of a significant differentiation of the indicator values between the northern and the southern EU countries and the provision of evidence about the imprint that the national urban planning policies may have on the urban ecosystem condition indicators. The results of the current study are expected to work as an aiding tool of policies and planning purposes that seek to ensure urban resilience and climate adaptation.