Post-abandonment dynamic on Mediterranean and sub-Mediterranean perennial grasslands: The edge vegetation of the new class Charybdido pancratii-Asphodeletea ramosi

A phytosociological study that was mainly aimed at describing the dynamic processes of Mediterranean and sub-Mediterranean perennial secondary grasslands is presented here, using the concepts tested previously for similar grasslands in temperate zones. The study was carried out in two different geographic areas: the Gargano peninsula, and the central Apennines between Marche and Umbria. Thirty-six phytosociological surveys were analyzed using cluster analysis. The study highlights that after the abandonment of agro-pastoral activities, in the ecotone zone between the grassland and the wood mantle, macrophytic, nitrophilous and sub-nitrophilous species spread rapidly. These species have underground organs of propagation (e.g., rhizomes, bulbs) that are mostly toxic to herbivorous animals, such as Asphodelus spp., Charybdis spp., Ferula spp., Thapsia spp., Asphodeline spp.. The communities that have participated in these processes are attributed to the new class Charybdido pancratii-Asphodeletea ramosi, within which the new order Asphodeletalia ramosi is described. This order includes four alliances: Charybdido pancratii-Asphodelion ramosi, Asphodelo ramosi-Ferulion communis, and Asphodelion fistulosi in the Mediterranean area; and Asphodelino luteae-Ferulion glaucae in the sub-Mediterranean area. Overall, six new associations and a new sub-association, feruletosum glaucae of the association Cephalario leucanthae-Saturejetum montanae, are described. Furthermore, the international literature on secondary perennial grasslands of much of the Mediterranean basin (i.e., Europe, north Africa, the Middle East) was studied to define the occurrence in these territories of the species considered to be important in the described dynamic processes. We can conclude that the same processes observed in the present study area occur across the whole Mediterranean basin.