High Nature Value Farmland (HNVF) and Ecological Networks: Their role in the sustainability of trans border regions

European policies have shown that the integration of environmental instances in the planning process and the sustainable land development are major objectives. The aim of this paper is to discuss the chronological evolution of the ecological network concept, some of the experiences at the European level and in the Alpine–Adriatic region and the role of agricultural areas in ecological connectivity. A case study on mapping High Nature Value Farmland (HNVF) in the Friuli-Venezia Giulia region (Italy) shows the importance of HNVF in the creation of a regional ecological infrastructure, as well as some problems associated with their identification and mapping at regional and trans-boundary levels.