Pathways of demographic and urban development and their effects on land take and ecosystem services: The case of Lisbon Metropolitan Area, Portugal

Abstract

Land use and land cover (LULC) changes, particularly land take by urbanization, can jeopardize ecosystems and their capacity to provide humans with numerous benefits, known as ecosystem services. A better understanding of the connections between land take, changes in complex LULC patterns and ecosystem services is still needed. Especially needed are forward-looking analyses that can support spatial planning in the face of targets like “no net land take,” as set in Europe. The aim of this research is to gain insight into the possible consequences of alternative pathways of demographic and urban development, in terms of land take and ecosystem services supply. Using the Lisbon Metropolitan Area in Portugal as case study, four contrasting scenarios for 2030 were developed that cover major determinants of land take (with a focus on residential development) and priority ecosystem services for the region, as well as deal with climate regulation, recreation and food production. Our findings suggest that the effects of urban development on land take are positive for a “compact city” and negative for an “urban sprawl” pattern, even for opposite demographic developments (growth versus decline). However, each pattern can have both positive and negative effects on the supply of ecosystem services. Hence, tensions can exist between the “compact city” model of urban development and the provision of ecosystem services to urban dwellers, especially across planning levels. We argue that the way land take is defined can influence the outcome of this kind of assessment, depending on which LULC dataset is used to support it. Exploring the approach developed in this research with different stakeholders while adopting more extreme scenario assumptions can provide additional insights on the topic.