Multi-proxy study of the Pialeloup Bog (SE Massif Central, France) reveals long-term human environmental changes affecting peat ecosystems during the Holocene

Abstract

In order to reconstruct local environmental changes affecting wetlands in middle mountain ranges, this study presents a multi-proxy analysis of the Pialeloup peat record on the Béage Plateau (South-Eastern Massif Central, France). It combines macrofossil, beetle, palynological, and geochemical data. The results are compared with other palaeoecological studies and archaeological data from the Massif Central, Jura Mountains and Alpine regions to discuss the links between local environmental changes and socio-economical dynamics at larger scales. Based on this approach, early environmental changes were highlighted between 6500 and 4800 BC, most certainly due to animal trampling on the Pialeloup bog. These events seem synchronous with human presence from the Late Mesolithic to Early Neolithic. It suggested that wild animals and human/livestock might have frequented the Béage Plateau wetlands. Then, long-term landscape management was documented for the last 3000 years. Local palaeoecological insights (synanthropic plants, beech-forest clearings, increasing erosion) and archaeological evidence for human settlements (pottery, millstones, and anthropogenic soils) were revealed to start during the Iron Age (400–200 BC). From the Late Iron Age to the Early Medieval period (150 BC–AD 725), human activities combined livestock pasture and local cereal cultivation (such as rye, Secale cereale, as a winter crop). This long-term management produced an open landscape where only small beech/fir woods persisted (Fagus sylvatica/Abies alba). This step was essential for the further development of extensive livestock grazing since the Medieval period in this region.