Vegetation reconstruction of the Agro Pontino and Fondi basin (central Italy) before and after the Bronze Age eruption of Somma-Vesuvius (c. 1900 BCE)

Abstract

In the research project The Avellino Event: Cultural and Demographic Effects of the Great Bronze Age Eruption of Mount Vesuvius, the recording of local and regional changes in the vegetation of the landscapes of the Agro Pontino and the Fondi basin (southern Lazio, Italy) before and after the Bronze Age eruption of Somma-Vesuvius (c. 1900 BCE) was central to answer the project’s central question, which revolved around the nature of the distal effects of this high-magnitude eruption on the conditions of living for the Bronze Age human population inhabiting these landscapes. If adverse effects of the ash fall in these areas were minor, the Agro Pontino and the Fondi basin, located about 125 km north of the Vesuvius, could well have been the refuge area people might have fled to in their attempts to escape the pyroclastic flows that eventually would bury parts of Campania around the Vesuvius below a thick layer of tephra. If adverse effects of the ash fall were major, the situation might, likewise, have led to changes in vegetation but could have resulted in a decline in human and animal presence due to toxicity, for instance. In both scenarios, either population growth due to in-migration or population decline due to environmental impact, we expected to see changes in the vegetation record in the period during which the Avellino Event occurred. To test our hypotheses, we performed archaeobotanical research, using pollen and macro-remains, on stratified soil sequences from test pits in the Agro Pontino and the Fondi basin containing the Avellino tephra layers, thereby guaranteeing sound chronological control. (The research revealed the presence of other known distal tephras as well.) Contrary to our expectations, the research did not provide proof of any significant changes in the vegetation around the date of the Avellino Event, nor did it provide any strong signs of human impact on these landscapes in the longer term before and after the distal ash fall, thereby indicating low population levels during the final part of the Early Bronze Age (EBA) and the initial phase of the Middle Bronze Age. Although this finding about human impact is an important outcome, it is not the only finding. The archaeobotanical research provided the project with high-resolution information on the vegetation and environmental conditions in the Agro Pontino and the Fondi basin for the duration of the Bronze Age. This, in combination with the physical-geographical data collected during the project, added significantly to our ability to perform detailed palaeogeographical reconstruction of the Agro Pontino and the Fondi basin. In addition, it increased our understanding of how the landscape had been settled during the Bronze Age (Sevink et al. 2022; Attema et al. in press). A final spin-off consisted of possible new information on the 4.2 ka climatic event that impacted Italy during later prehistory, as reflected in the pollen diagrams presented.