Two Holocene lake sequences from Lac de Creno, Corsica were analysed
on the basis of 119 pollen spectra and
with the support of 13 14C-calibrated dates. The lower part
of one of these sequences, corresponding to the late-
glacial period, has been published previously. The first third of the Post-glacial
is characterized by very particular
forest dynamics, namely the absence of a role for deciduous Quercus
and Corylus, the presence of mesophilous
vegetation types dominated by Taxus, and the major forest role
of Erica arborea at lower and mean altitude. At
about 7440 cal BP, the occurrence of a major anthropogenic action brought
about significant changes in the
vegetation, notably an increase of deciduous Quercus and the expansion
of Quercus ilex. Later, three major human-induced events are identified: the first, at about 2290 cal BP, is the
cause of a short local expansion of Abies; the
second, at about 1150 cal BP, is the degradation of deciduous forests to
the benefit of Fagus; the third, at about
310 cal BP, corresponds to the disappearance of Fagus and its
replacement by Pinus. Pollen data indicate that Q.
ilex, Abies and Fagus are not indigenous in Corsica
but spread there during the Postglacial ; this probably took
place at about 6980 cal BP for Q. ilex.