Trends of plant communities growing on the Etruscan tombs (Cerveteri, Italy) related to different management practices.

Vegetation management of archaeological sites is a recurrent problem when considering the conservation of historic structures and biodiversity. In the UNESCO site of the Etruscan necropolis "La Banditaccia" (Cerveteri, Italy), several plants grow on the ancient tumuli, which are subjected to different management practices. In order to assess the influence of interventions on plant colonisation, a comparative analysis of several tumuli was performed, through structural, chorological, phytosociological and statistical evaluations. This investigation identified and defined an ecological gradient among the tumuli. The cover values of Therophytes and Hemicryptophytes decreased by half with regular cutting, while those of Geophytes and Phanerophytes increased. Mesophilic field plants (MFP), both ephemeral and perennial, represented the most abundant group. Mediterranean bushes and forests (MBF) showed a positive trend from the entrance to the last tumuli of the necropolis. This trend was clearly defined by PCA, and it seems community changes were caused by the absence of mowing activities and to a lower tourist frequentation. SIMPER analysis highlighted which species on each tumulus mainly influence their dissimilarity. This knowledge, when combined with the evaluation of the potential risk of the different plant communities growing on the tumuli, can help to identify the best management practices. [ABSTRACT FROM AUTHOR]