Abstract
Developed by agronomists, the agro ecosystemic model Lund-Potsdam-Jena-managed-Land simulates potential yields of main cultivated crops worldwide using climate data in entry. LPJmL runs for rainfed and irrigated cultures. This kind of modeling has been recently adaptated for the study of the past with paleoclimatic data*. The figure beside shows potential yields for grapes (in hectoliters/ hectares) for two centuries which climate was very different: the 6th c. BCE (very cold and dry) and the 1st c. BCE (very hot and wet). According to the model and paleoclimate data, the potential yields of the 1 c. BCE appear very higher (25%-50%) than for the 6th c. BCE. This result supports the hypothesis that the so-called Roman Climate Optimum or Roman Warm Period (2nd c. BCE-3rd c. AD) would have been very favorable for the development of vineyards in Gaul.