The Alento Observatory for Agro-Environmental Research in the Mediterranean: Integrating Critical Zone Monitoring and Open-Air Laboratory Data (Dataset)

The agro-environmental observatory established in the Alento River Catchment (ARC; southern Italy) represents a strategic critical zone for investigating hydro-geo-meteorological dynamics within the complex Mediterranean pedoclimatic context. Since 2016, it has served as a key component of the European TERrestrial Environmental Observatories (TERENO) long-term ecosystem infrastructure network. At the outset, two sub-catchments of the upper catchment (UARC; 102 km2) were similarly equipped with wireless sensor networks, cosmic-ray neutron sensors, piezometers, and meteorological stations. This continuous record has been augmented by field campaigns involving hydro-geophysical surveys (EMI, ERT), stable water isotope sampling (d2H and d18O), drone imaging and satellite remote sensing, together with targeted in-situ soil hydraulic experiments. Analyses were conducted to monitor the water yield at the Piano della Rocca dam and the water level of the Alento river at the outlet of the lower part of the entire catchment (LARC; 309 km2). These datasets offer a holistic understanding of water fluxes and storage, turning ARC into an effective synthesis between a critical zone observatory (CZO) and an Open-Air Laboratory (OAL). The integrated monitoring approach and data fusion technique are essential for developing and validating ecohydrological models. This will help assess soil health under the EU Soil Mission framework and predict how shifts in Mediterranean climate seasonality and land use will affect the availability and sustainable management of vital water resources.