Evolution of productive and biodiversity features in lucerne fields of different ages

Medicago sativa is a legume forage crop characterized by high production of forage, with a notable nutritive value, but in mountain areas duration of the crop could be remarkably affected by severe environmental conditions. To assess the vegetation evolution of lucerne crops in relation to crop age, data from fields of lucerne of different ages were collected. The aim is the evaluation of lucerne productive performances, evolution of forage quality and assessment of recovery by autochthonous species that naturally recolonize the studied areas in relation to age of the cropped species. With increasing years, lucerne population was significantly decreased and replaced by different functional types of plants, such as perennial graminoids and short-lived forbs. Biodiversity increased significantly along time, and evolution of similarity indices demonstrated an evolution of vegetation toward that represented by reference grassland of the area. Productive characteristics of forage, in terms of aboveground biomass and quality, were negatively affected by age. Results permitted to assess the evolution of different features of lucerne for a mountain environment and to hypothesize the appropriate management for this resource, that could contemplate also the evolution towards the reconstitution of the reference habitat for the studied area.