Landscapes and human interaction with the environment in the middle Erdre River valley from the Neolithic Age until the present: A pollen study of the Lisle marsh

The Erdre River valley is particularly characteristic of the landscape chan ges that have occurred since the end of the last glaciation Numerous peat b ogs have filled in small valleys all along the course of the river, providi ng a record of variations in plant life due to natural or human causes. Fro m the mid-Neolithic Ages, farming was practised in this region and the waln ut tree was introduced. During the Bronze and Iron Ages, cereal growing bec ame more extensive, walnut plantations were developed, boxwood and buckwhea t appeared, and the first vineyards were probably planted. The chestnut tre e only appeared during the Gallo-Roman period. The variations observed in t he bog landscape during the Middle Ages were probably due to the establishm ent of dams to control the flow of the Erdre. In the modern and current per iods, non-indigenous species, such as the sequoia were introduced (in relat ion with the triangular slave trade), and maize began to be grown extensive ly in the 1950s.