In Central Tyrrhenian Italy and more precisely in Etruria, a region inhabited by the Etruscans, rapid and important changes, part of a process of urbanization, have been documented from the 10th to the 6th centuries BCE (3000 to 2500 BP). They led to the emergence of large cities with complex political, economic and social structures. This period seems to be punctuated by diverse climatic events which could have influenced the annual precipitations and temperatures but also their seasonality. This climate instability cannot be sidelined as a parameter that could have triggered these societies transformations. However, because of the strong anthropic impact on the environment and the lack of resolution of the climatic studies, it is complicated to assess the relationships between these factors. To improve the comprehension of these interactions this project will focus on the study of agricultural practices, which can reflect socio-economic characteristics of a society, as well as climatic variations occurring during this period at the archaeological site of Tarquinia in Etruria, an ancient region situation north of the Tiber. Forty samples having charred archaeobotanical material dated between the 10th to the 7th cent. BCE are already available for this study. The principal method used is carbon and nitrogen stable isotope analysis (¿13C and ¿15N) of carbonized cereals and woods remains found in these samples. The results will be completed with an ecological study of the weeds which are plants growing in association with cultivated cereals. The study of an Etruscan site provides a useful comparanda for the interpretation of the data that is part of my PhD project, which focuses on the Latium vetus region. The presence of diverse archaeological cultures and environmental differences between the two regions permits to better discriminate the anthropic impact from the climatic influence.
A considerable amount of data on both climatic change and urbanization exists for the Mediterranean region and Central Tyrrhenian Italy. However, comparing these two very different types of data is a complicated matter (Berglund (2003) Quat. Int., 105(1), 7-12; Finné & al. (2019) The Holocene, 29(5), 847-863). First, the mechanisms which drive climate are numerous and complex and they can lead to different and non-synchronous responses at a regional or even local scale (Finné & al. (2019); Manning (2013) In: The ancient Mediterranean environment between science and history; Pèlach & al. (2011)). Moreover, according to the proxy used different aspects of the climate are assessed, some will be more sensitive to seasonal changes or will inform on local trends, while others will give more global results (Finné & al. (2019); Magny & al., 2013). For some proxies such as pollen in periods of strong human pressure, as is the case for our period and region of study, (Mercuri & Sadori (2012) Rendiconti online della società geologica Italiana, 18, 32-34), it is complicated to discriminate climate variations and human influence. Regarding the archaeological studies, the response of societies to a climate event can vary according to the political and social characteristics of the society (Manning, 2013). But the major difficulty is that the time-scale covered by the climatic studies is usually longer and has a lower resolution than the archaeological studies (Berglund (2003); Mensing & al. (2015) Quat. Sci. Rev., 116, 72-94). It then becomes challenging to synchronize an archaeological event taking place over a few decades or centuries with a climatic one. This is why this study proposes an innovative approach to set new climatic records giving local information to an entirely human scale with the use of stable isotope analysis (¿13C) on charcoals. Moreover, the stable isotope analysis (¿15N and ¿13C) on cultivated cereals will provide totally new information about agricultural practices and their possible evolution over time and between two distinct cultural regions. Little is known about the processes used in crop production and the only evidence existing is all indirect such as tools, texts, landscape managements or products of this agriculture. More generally, even if data has already been provided for some Mediterranean sites, both for ¿15N and ¿13C (Aguilera & al. (2008) Rapid Comm. Mass Spectrom. 22(11), 1653-1663.; Alagich & al. (2018) J. Archaeol. Sci., 93, 135-149; Araus & al. (1997) J. of Archaeol. Sci., 24(8) 729-740; Bogaard & al. (2016) Veg. Hist. Archaeobot. 25(1), 57-73; Fiorentino & al., (2012) Rapid Comm. Mass Spectrom. 26(3), 327-335) no data has been yet published for Central Italy. The results acquired with this study will be innovative and will contribute to filling the gap of information for this region. Finally, these new data will be compared to the stable isotopic data coming from the archaeological site of Gabii studied during my PhD project. This sited is situated in the ancient Latium vetus region and was inhabited by the Latins which represent a different culture emerging in Central Tyrrhenian Italy at the same period than the Etruscans. Latium vetus was located at the south of the Tiber river. The Latins shared with the Etruscans the same pattern of urbanization and followed the same chronology but differed in their practices and organization. Comparing the two regions is interesting to see if they had the same farming practices. It will also help to better interpret the stable isotopic results. Indeed, the fact that they are distinct ethnicities which inhabit similar environments (soils, geomorphology, distance from the sea) permit to discriminate what is due to human impacts and choices and what can be attributed to climatic changes.