Evolution of hay meadows between 1956, 1986, and 2016 and its relation to the characteristics and location of the parcels in the valley of the river Esera (Pyrenees, Spain)

The uses of the agricultural surface of hay meadows and crops of the mountain areas of the Spanish central Pyrenees are subject to constant transformations. This paper addresses the changes produced in the hay meadows of the Ésera river valley of the central Pyrenees (Spain) regarding the surface and the agronomic and topographic characteristics of the parcels between 1956-1986 and 1986-2016. The cartographed area is 5226 hectares, of which 1941 hectares correspond to 6416 polygons that have been mowed or cultivated on one of the three reference dates. In the period 1956-1986, there is a reduction in the agricultural area of meadows and crops (13.59%) in favor of pastures, forest, urbanized land, and water reservoirs. The surface of the meadows increases to 301.58%, to the detriment of the crops, until almost their disappearance. Between 1986 and 2016, the area of meadows is reduced to 59.11%, and the area of pastures, forests, and urbanized land increases. The topographic characteristics of the parcels with respect to surface, altitude, slope, width, and terracing and distance to the communication routes determine mechanized access and management and discriminate the transformation to pasture and forest