An archaeobotanical and stable isotope approach to changing agricultural practices in the NW Mediterranean region around 4000 BC.

It has recently been observed, that a change in the crop spectrum happened during the so-called Middle Neolithic in France at ca. 4000 BC. An agricultural system based on free-threshing cereals (naked wheat and naked barley) seems to shift to one based on glume wheats. This is a major change for traditional farmers and this paper aims to shed light on its possible causes. Here we describe the results of new investigations in a key area for the understanding of this process: the NW Mediterranean arch, where free-threshing cereals are the main cultivars since ca. 5100 BC. New data confirm that the shift towards glume wheats is also observed in some sites of the NE of the Iberian Peninsula and that among the glume wheats that spread at ca. 4000 BC we should not only consider emmer and einkorn but also Timopheevi's wheat. Stable isotope analyses indicate no major decrease in soil fertility or alterations in local precipitation regimes. The agricultural change may be the result of a combination of the spread of damaging pests for free-threshing cereals and presumably new networks being developed with the North-eastern part of Italy and the Balkans.

Archaeobotanical and isotopic analyses of waterlogged remains from the Neolithic pile-dwelling site of Zug-Riedmatt (Switzerland): Resilience strategies of a plant economy in a changing local environment.

The excellent preservation of the waterlogged botanical remains of the multiphase Neolithic pile-dwelling site of Zug-Riedmatt (Central Switzerland) yielded an ideal dataset to delve into the issue of plant economy of a community spanning several decades. The study identified a major change in crops where oil plants played a key role in the site's initial phase before being supplanted over the course of a few decades by naked wheat, barley and pea. Wild plants continued to be gathered albeit in different proportions. In the latest settlement phase, the changes in the local vegetation and in the values of the analyses of carbon stable isotopes suggest a less humid environment. The hypothesis is that the changes perceived in the plant economy represent a resilience strategy adopted by the inhabitants in reaction to short term local climatic alterations. The two types of soil sampling techniques (monolith and bulk) allowed comparing these results. While the density of plant remains appears to be underestimated among the samples collected by the monolith technique, the proportions of economic taxa remain unaffected. The findings thus reveal that when the bulk samplings are distributed carefully throughout multiphase sites and avoid mixing stratigraphical units, and if the samplings are representative of all archaeological features from a whole area, then each of the two techniques offer analogous results.

Small Animals, Big Impact? Early Farmers and Pre- and Post-Harvest Pests from the Middle Neolithic Site of Les Bagnoles in the South-East of France (L'Isle-sur-la-Sorgue, Vaucluse, Provence-Alpes-Côte-d'Azur).

Pests appear to have accompanied humans and their crops since the beginning of farming. Nevertheless, their study is only rarely integrated into research on farming in prehistory. An assemblage of invertebrates and small mammals was recovered from the waterlogged layers of three wells at the Middle Neolithic site (4250-3700 cal B.C.) of Les Bagnoles (SE France). The microfaunal remains were retrieved from sediment samples by wet sieving (wash-over technique). The most common among the rodents is the wood mouse. The assemblage also consists of insect remains of grain weevil, seed beetle, and corn ground beetle. The different finds not only offer data on the role of insect and rodent pests in the Neolithic but on the possible strategies adopted by the early farming communities in the western Mediterranean in response to pest infestation. The findings appear to confirm the hypothesis that the wood mouse was a commensal and storage pest in settlements long before the arrival of the invasive house mouse during the Bronze Age. The presence of the main storage pest, the grain weevil, suggests a long-term grain storage issue at Les Bagnoles. The combination of the results of the site's archaeobotanical findings with those of other sites in the western Mediterranean suggests that the shift from naked to glume wheat around 4000 B.C. may also stem from a reaction to the problem of grain weevil infestation.