Assessing long-term impact of land-use change on hydrological ecosystem functions in a Mediterranean upland agro-forestry catchment Paolo Nasta a , Mario Palladino a , Nadia Ursino b , Antonio Saracino c , Angelo Sommella a , Nunzio Romano a, ⁎ a Dept. Agricultural Sciences, AFBE Division, University of Napoli Federico II, Portici, Naples, Italy b Dept. ICEA, University of Padova, Padua, Italy c Dept. Agricultural Sciences, BIPAF Division, University of Napoli Federico II, Portici, Naples, Italy HIGHLIGHTS • AGWA model is used to compute water/ sediment budgets for three historical land-use maps of 1955, 1998, and 2015 • DREAM ZS global-optimization tool is used for model calibration purposes • On a demand-side thinking, afforesta- tion occurred during the last decades reduces W y and increases ET a • On a supply-side perspective, monthly W y value is sensitive to rainfall occur- rence that is increasing in the last decades GRAPHICAL ABSTRACT abstract article info Article history: Received 31 January 2017 Received in revised form 19 May 2017 Accepted 2 June 2017 Available online xxxx Editor: D. Barcelo During the second half of the 20th century farming systems in hilly and mountainous areas of Mediterranean Europe were progressively abandoned and the forest cover subsequently re-expanded. This paper investigates the environ- mental impacts of land-use/land-cover (LULC) changes on hydrological ecosystem functions (HEFs) in the Upper Alento River Catchment (UARC) in southern Italy. We document the human-driven post-war landscape in 1955 with its maximum expansion of pasture and crops. By 1998 forest cover had doubled and cropland had roughly halved due to decades of land abandonment and reduction in human pressure. In 2015 secondary forests occupied about 70% of the catchment and orchards about 20%. The 1998 land-use scenario was implemented within the Au- tomated Geospatial Watershed Assessment (AGWA) model which was calibrated and validated by direct water yield measurements recorded in the period 1995–2004 in the water reservoir delimited by an earth-dam located at the UARC outlet. Numerical simulations, assumed under “steady” climate conditions, offer “pseudo-realistic” sce- narios that help interpret differences in water budget and sediment transport when the 1998 land-use scenario is compared to those of 1955 and 2015. With reference to funding opportunities offered by the European Union in the recent decades, this study provides some practical guidance on the impact of cropland reconversion on HEFs and on measures to mitigate soil erosion in this Mediterranean area. Viewed from the demand-side perspective, nat- ural re-expansion of forest and afforestation reduce water yield and increase actual evapotranspiration. However, our modeling results are framed also within a supply-side approach examining the sensitivity of water yield to pre- cipitation characteristics. © 2017 Elsevier B.V. All rights reserved. Keywords: Rural abandonment Afforestation Water yield Soil erosion Mediterranean climate AGWA-SWAT Posterior parameter estimation DREAM zs Science of the Total Environment 605–606 (2017) 1070–1082 ⁎ Corresponding author at: Department of Agricultural Sciences, Division of Agricultural, Forest and Biosystems Engineering, University of Napoli Federico II, Via Università n. 100, Portici, Naples, Italy. E-mail address: nunzio.romano@unina.it (N. Romano). http://dx.doi.org/10.1016/j.scitotenv.2017.06.008 0048-9697/© 2017 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv