Palaeoenvironments and cultural landscapes of the last 2000 years reconstructed from pollen and Coleopteran records in the Lower Rhone Valley, southern France

For the first time, a high-resolution pollen/Coleoptera joint analysis is p erformed on a late Holocene sedimentary sequence located in the Lower Rhone Valley.C-14 dates validated by pollen data show that the bottom of the seq uence is contemporaneous with the Greco-Roman period whereas the top is att ributed to the present. This sequence yielded very rich pollen and insect a ssemblages, enabling a detailed reconstruction of the palaeoenvironment suc cession during the two last millennia around the site itself and more widel y in the Aries plain. The very low pollen representation of trees and the n ear absence of tree-dependent Coleoptera suggest a marked deforestation of the area. The abundance of dung-beetles and nitrophytes is also in keeping with a strong grazing impact throughout the sequence. Three agricultural ph ases reflecting a growing level of human activities are identified. Phase 1 is contemporaneous with Celto-ligurian, Greek and Roman civilizations in P rovence. At this time the forest cover was already largely destroyed, and p astoralism, cultivation of cereals, olives, vines and walnuts, was practise d. Phase 2 is contemporaneous with a period spanning the Merovingian time a nd the Upper Middle Ages. It is characterized by increased agro-pastoral ac tivities, probably related to the establishment of a monastic community at the Montmajour Abbey and to the settlement of farmers on the nearby Castell et hill. The major characteristic of agricultural phase 3 is the very high pollen percentages of Dipsacus fullonum or teasel, which was formerly exten sively cultivated for cloth teasing. This early cultivation of an industria l plant, dated at La Calade to the twelfth century, is recorded for the fir st time in Provence. It may be connected with craft industries performed by monks at Montmajour Abbey. The sedimentological data suggest a succession of two stability phases interrupted by three Rood phases. This interpretati on agrees both with insect data: the fluctuating abundances of which are ce rtainly connected with the alternation of ground submersion and dry periods , and with pollen data, marked by the impact of the hoods upon the marshy v egetation. However, no clear climatic signal is recorded.