The vegetation reconstruction of the Pompeii area between the 1st millennium BC and AD 79

The AD 79 eruption of the Vesuvius severely affected the Sarno River floodplain in the surrounding of Pompeii. The landscape was covered with volcanic materials that destroyed the ecosystem but, at the same time, preserved the traces of former environmental conditions (Vogel and Märker 2010). The palaeoenvironmental reconstruction of the floodplain and its evolution in relation to the past urbanization has recently benefited from new archaeological (Furlan et al. 2019) and geomorphological (Nicosia et al. 2019) data from the area between the city, the river meander belt, and the sea. In particular, this study provides the first pollen sequence reconstructing the plant landscape before and during the life phases of the city. In order to outline the natural and anthropogenic features of the local vegetation, a total of 29 pollen samples have been recovered from two sediment cores (S5 and S6) drilled immediately south to the Sarno Baths, the thermal complex located along the southern section of the city wall. A succession of organic layers were identified under the AD 79 eruption deposits as result of flooding activity of the Sarno River from 900-750 BC onwards. Results of the palynological analysis depict an open environment with a mosaic of vegetation types since the Early Iron Age. The local presence of Mediterranean coastal shrubland, hygrophilous riverine forest, and mesophilous plain forest is combined with the regional contribution of mountain vegetation. Oscillations between inundated and wet ground characterized the area (Nicosia et al. 2019). Such a natural environment shows anthropogenic traits since the base of the sequence: pasturelands, cultivated fields, and olive groves which probably occupied drier soils. The most important change in the land use system was the introduction of cabbage cultivation in the 4th century BC and its intensification from the 2nd century BC, when Roman influence grew. The presence of tree crops and of ornamental trees reveals the opulence of the Imperial age, until the catastrophic eruption (Vignola et al. 2021). This study has revealed for the first time the main traits of the local and regional vegetation in the Sarno River floodplain during the whole 1st millennium BC, before and during the birth, rise, and destruction of Pompeii.