Abstract
From all the sites studied, the anthracological approach applied to the historical period has made it possible in Poitou-Charentes to bring new elements to the paleoenvironmental and paleoecological study. Until now, this region was known only thanks to palynological studies relating to the coastal marshes as well as those of the Angoulême area. By exploring the plains sites (Poitiers, Chassenon, Rom, Melle, Airvault), it was possible to analyze human behavior and relate the importance of human occupation to the implementation of a supply strategy suggesting the possibility of reasoned management within the framework of a wood economy ( case of Poitiers). Urban development models would seem different from those of rural areas. Through this study, the anthracological data suggest that the concepts of anthropization and reasoned choice of species present nuances that need to be clarified. There is not one pattern of interaction but several. Deepening the analysis of human interactions.The evolution of the ratio of deciduous oaks / beech (Fagus sylvatica L.) constitutes a privileged axis of research. It reflects the evolution of the supply territory when it is correlated with the absence of significant relative frequencies of taxa characteristic of moors or armed wastelands. This can be verified by using the Pareto concentration index. It appears that frequencies of 65% for deciduous oaks and around 15% for beech may correspond to supply territories from poorly transformed formations.It will be necessary to confirm this correlation observed from these sites which cover only a tiny part of Poitou-Charentes. Indeed, the Saintonge has been little studied. The results for this area may be different.For the important evolutions, the beech did not have to disappear following a voluntary elimination from the Gallo-Roman period. The causes are most certainly to be found in the reduction of forest areas during the medieval period. For the chestnut (Castanea sativa Mill.), even if its frequency becomes significant but not very important during the high Middle Ages, it does not seem that its extension is prior to the end of the Middle Ages. The two findings may be related.With regard to the major transformations, no substitution of series of vegetation inherited from the beginning of the Subatlantic as in Haut-Médoc, nor the significant development of moors or armed wastelands from the Gallo-Roman period have been observed. This provides the Haut-Poitou area with new elements for understanding the genesis of the so-called "Brandes" landscape which will characterize two-thirds of Vienne during the modern era.