Mismatches between ecosystem services supply and demand in urban areas : a quantitative assessment in five European cities

摘要

Assessing mismatches between ecosystem service (ES) supply and demand can provide relevant insights for enhancing human well-being in urban areas. This paper provides a novel methodological approach to assess regulating ES mismatches on the basis of environmental quality standards and policy goals. Environmental quality standards (EQS) indicate the relationship between environmental quality and human well-being. Thus, they can be used as a common minimum threshold value to determine whether the difference between ES supply and demand is problematic for human well-being. The methodological approach includes three main steps: (1) selection of EQS, (2) definition and quantification of ES supply and demand indicators, and (3) identification and assessment of ES mismatches on the basis of EQS considering certain additional criteria. While ES supply indicators estimate the flow of an ES actually used or delivered, ES demand indicators express the amount of regulation needed in relation to the standard. The approach is applied to a case study consisting of five European cities: Barcelona, Berlin, Stockholm, Rotterdam and Salzburg, considering three regulating ES which are relevant in urban areas: air purification, global climate regulation and urban temperature regulation. The results show that levels of ES supply and demand are highly heterogeneous across the five studied cities and across the EQS considered. The assessment shows that ES supply contributes very moderately in relation to the compliance with the EQS in most part of the identified mismatches. Therefore, this research suggests that regulating ES supplied by urban green infrastructure are expected to play only a minor or complementary role to other urban policies intended to abate air pollution and greenhouse gas emissions at the city scale. The approach has revealed to be appropriate for the regulating ES air purification and global climate regulation, for which well-established standards or targets are available at the city level. Yet, its applicability to the ES urban temperature regulation has proved more problematic due to scale and user dependent constraints.