Hydrological ecosystem services: from supporting to provisioning agroecosystem services in the Circeo National Park

In this paper, it has been assessed, modeled and quantified the change in the delivery of two hydrological ecosystem services (HES) from agriculture and livestock sector, one regulating (water supply), and one provisioning (e.g. food, fiber). Water supply, in other words green water, due to agriculture, was calculated using evapotranspiration (ET) which is defined as evaporation of water from land and water surfaces and transpiration by vegetation. Evapotranspiration is important in water resources planning, to understand crop water needs for optimal crop production by either meeting the crop water requirement or avoiding crop water stress during drought season. In the Circeo National Park, in the last 30 years, the assessment of HES has dealt to robust and sensitive (due to global changes) procedures as biophysical and economic indicators system, ad hoc statistical models and analysis related to space-time and ecological and socio-economic aspects - e.g. scale, dimension, patterns, driving forces, changes, scenarios, land use and landscape management, climate change, spatial planning, regional development and financial policies -. In this contest, it has been evaluated the effects of alternative future scenarios that describe varying degrees of agroecosystem used on hydrological response related to water supply. HES are estimated through ecosystem accounting methods that combine environmental and economic concepts. In this study, it has been used an ecosystem accounting approach to show the development of water supply and provisioning services. The value of HES has been estimated considering the following three main phases: measuring the provision of ES; determining the monetary value of ES; designing policy tools for managing ES. The second step of valuation of ES includes both market and non-market evaluation.