Multi-criteria participative evaluation of Pinus halepensis plantations in a semiarid area of southeast Spain

Semiarid areas host several hotspots of biodiversity, and provide vital ecosystem services. Afforestation has been extensively used to restore these areas. However, studies on the impact of afforestation on the provision of ecosystem goods and services are scarce. We have evaluated changes in the provision of ecosystem services after afforestation in a semiarid area in southeastern Spanish. Through a multi-criteria analysis, Pinus halepensis plantations were compared to four unrestored landscape units (grasslands, Stipa tenacissima steppes, shrublands and abandoned agricultural fields), using six ecological and socioeconomic criteria and fourteen indicators. The weights of criteria and indicators were obtained from the opinion of 38 stakeholders. The values of each indicator per landscape unit were obtained from empirical data and bibliographic sources. From the stakeholders' perspective, regulating and supporting services and biodiversity were more important than provisioning, cultural and economical services. Pine plantations enhanced ecosystem services as hydrological and climatic regulation, and aesthetic value, but decreased the provision of other services as forage productivity, water availability, and small and big game habitat. Pine plantations provided the highest levels of ecosystem services. The multi-criteria and participatory assessment allowed managers to check the overall impact of their decisions, and it represents an efficient tool for reciprocal learning and negotiation.