Palaeoecology

Palaeoecology

The Agro Pontino and Fondi basin. A: higher Pleistocene marine terraces, B: low-lying Agro Pontino Graben, C: Fondi basin
The Agro Pontino and Fondi basin. A: higher Pleistocene marine terraces, B: low-lying Agro Pontino Graben, C: Fondi basin

Pollen and macrofossil data will be used to reconstruct the vegetation in the coastal wetlands of south Lazio before and after the Avellino eruption. The aim of this work is to detect the environmental impacts brought about by the influx of the postulated substantial body of immigrants from Campania. Generally, an increase in population density leads to increased deforestation and anthropogenic land use, both of which can be detected through the analysis of pollen and botanical macro remains.

The macrofossil research will give information on the vegetation history at site level, while the regional vegetation development can be obtained from the pollen data. In contrast to the pollen signal, seeds and fruits are identifiable to species level. Moreover they can provide taphonomic information suitable for building up a picture of the local food economy. Dr. Marieke Doorenbosch will conduct and publish the pollen analysis, supervised by Prof. Corrie Bakels. The plant macrofossil work will be done by Dr. Mike Field with the help of Erica van Hees BA.

New pollen corings are needed because past cores do not cover enough parts of the ancient lakes and their surroundings to provide the high resolution data needed. From every core only those parts will be analyzed which help to solve our questions concerning the possible impact of the Avellino eruption on the population of the Fondi Basin and the Agro Pontino. Sampling locations for both palynological and plant macrofossil investigations will be carefully chosen from the margins of the former lakes within the Pontino and Fondi sedimentary basins to provide suitable archaeobotanical data, taking into account the requirements of all three researchers. These requirements include obtaining data from those landscape zones that are most likely to reflect changes in habitation and land use. The interpretation of the pollen diagrams also relies on collaboration between the researchers. For example, the effects of lake level changes on the vegetation and land use will have to be modeled, and certain potential anthropogenic indicators must be interpreted in the light of available archaeological knowledge.

Sediment samples will be taken from cleaned sections or by taking cores. It is envisaged that four cores/sections will be sampled and analyzed from the larger Agro Pontino sedimentary basin, and three cores/sections from the Fondi basin. High resolution sub-sampling of the cores and monoliths from the sections around the Avellino tephra layer will provide a detailed record of how the environment changed immediately after that event. Preliminary investigations on two sections from the Agro Pontino plain have already shown that relevant archaeobotanical data can be generated (Bakels et al. 2015). A fine chronology will be produced using the characteristic Avellino tephra layer and the results from eight AMS dates obtained from terrestrial plant macrofossils.