Syntaxonomy and synecology of Hedysarum brigantiacum communities in the western Italian Alps

Hedysarum brigantiacum is an endemic taxon recently typified in the southwestern Alps (France and Italy). In order to describe the phytosociologic and syntaxonomic aspects of H. brigantiacum communities, data from fifteen relevés realized on the Italian side of the Alps were analyzed. A new subassociation hedysaretosum brigantiaci is described within the Seslerio-Avenetum montanae. Two edaphic variants are identified within this subassociation: (1) var. with Festuca violacea, generally found at high altitudes on moderately steep slopes in soil of moderate organic matter accumulation, and (2) var. with Festuca quadriflora, characterized by relatively high slopes at moderate altitudes and rocky soils. Seslerio-Avenetum montanae hedysaretosum brigantiaci conservation depends on environmental factors and grazing management. Grazing should be carefully controlled to maintain relatively oligotrophic conditions by avoiding succession dynamics toward eutrophic coenosis.