Contexte paléoenvironnemental d'un lac à troncs subfossiles

This research specifies the palaeoenvironmental context (mainly the occurrence of fires and the rate of sedimentation) of a lake containing an important deposit of subfossil trunks used to develop a millennial dendroclimatic reconstruction within the framework of the ARCHIVES project (Chapter 18). Charred ericaceous macroremains in the soils of the riparian forest at site L18 have been dated with radiocarbon and corroborate the fire history reconstructed from the recruitment sequences of subfossils in the lacustrine littoral zone over the past millennium. Geochemical analyzes show that sediment inputs to the lake and limnological conditions have not changed significantly during this period. Consequently, although the fires influenced the regularity of the supply of subfossil trunks, they did not influence their conditions of conservation in water.