Strategic environmental assessment and enhancement of ecosystem services: a study concerning spatial planning in Sardinia (Italy)

Ecosystem Services (ESs) deliver benefits to human beings by providing them with goods and services, by regulating or supporting natural processes in order to improve life quality, and by increasing the cultural level of local communities. These services are produced by ecosystems, that is “dynamic complex[es] of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit” (United Nations, 1992, Article no. 2). Human-induced land-use changes have shaped landscapes and modelled structures and functions of ecosystems, to the extent that they are regarded as the main drivers of alteration of ESs. Land-use changes usually entail a trade-off between ESs because they boost one or more services while reducing others. Hence spatial planning, with its ex-ante spatial allocation of land uses, can play a key role in preserving healthy ecosystems and ensuring a balanced trade-off between ESs. In this study, we discuss the role of ESs as factors that improve the effectiveness of Strategic Environmental Assessment (SEA)-based processes; more precisely, we investigate how the integration of ESs into SEA-based processes can benefit Management Plans (MPs) of sites that belong to the Natura 2000 network and lead to higher levels of environmental quality. The discussion is based on a logical framework that accounts for the identification of objectives related to the provision of ESs; this can be regarded as a tentative specification of the general objective of environmental sustainability which is the foundation of the SEA of MPs. Moreover, by building upon Mascarenhas et al. (2015) and by taking the Sardinia region (Italy) as a case study, we examine the extent to which ESs are being taken into account in the SEA of spatial plans.