A marine/terrestrial integration for mid-late Holocene vegetation history and the development of the cultural landscape in the Po Valley as a result of human impact and climate change

Marine/terrestrial integration of pollen data contributes to the reconstruction of thetiming of climate-human forces that shaped cultural landscapes in the Italian peninsula. The paperfocuses on the relation between natural and human landscapes, and the development of the culturallandscape from the Bronze age to the Medieval and modern times. Two records were studiedwithin independent projects: the marine core RF93-30, central Adriatic, with a sediment sourcearea including the Po Valley, spans the last 7000 years; material from the Terramara di Montalethat was settled in the Po plain from approximately 3550 to 3200 cal B.P. The original chronologyof the marine core was developed by using the magnetic inclination of the secular variation recordand two 14C datings carried out on benthic and planktic foraminifera (at 527 and 599 cm of depth).Its pollen record shows a gradual irreversible trend towards increasing aridity since 5700 cal B.P.and, just after around 5100 cal B.P., Picea decline and Quercus ilex type increase marked less coolconditions. Human impact introduces rapid changes, as the decrease of silver fir, thinned by thereduction of precipitations and further cut before/at the early Bronze age, followed by the fall ofoaks. The latter started after around 3900 cal B.P., and became evident at around 3600 cal B.P.The gradual landscape openness and forest clearance correspond to the onset of Middle Bronzeage settlements in the Po Valley, and to the development of the cultural landscape in the region.The impact of terramaras includes wood management by coppicing, and patching of the territory inpastures and fields. Xeric environments (Cichorioideae), resulting from the continuative humanpressure, spread since the Recent Bronze age. In the multi-causal explanation for the decline ofterramaras event, we suggest that climate would have been less important in the decline than in theonset phases. The further human landscapes were mainly traced by the trends of Olea, Juglans and Castanea while modern times were marked by the findings of Zea mays