We used a new sedimentary record to reconstruct the Holocene vegetation and fire history of GorgoBasso, a coastal lake in south-western Sicily (Italy). Pollen and charcoal data suggest a fire-prone opengrassland near the site until ca 10,000 cal yr BP (8050 cal BC), when Pistacia shrubland expanded and fireactivity declined, probably in response to increased moisture availability. Evergreen Olea europaea woodsexpanded ca 8400 to decline abruptly at 8200 cal yr BP, when climatic conditions became drier at othersites in the Mediterranean region. Around 7000 cal yr BP evergreen broadleaved forests (Quercus ilex,Quercus suber and O. europaea) expanded at the cost of open communities. The expansion of evergreenbroadleaved forests was associated with a decline of fire and of local Neolithic (Ficus carica–Cerealiabased) agriculture that had initiated ca 500 years earlier. Vegetational, fire and land-use changes ca7000 cal yr BP were probably caused by increased precipitation that resulted from (insolation-forced)weakening of the monsoon and Hadley circulation ca 8000–6000 cal yr BP. Low fire activity and densecoastal evergreen forests persisted until renewed human activity (probably Greek, respectively Romancolonists) disrupted the forest ca 2700 cal yr BP (750 BC) and 2100 cal yr BP (150 BC) to gain open landfor agriculture. The intense use of fire for this purpose induced the expansion of open maquis, garrigue,and grassland-prairie environments (with an increasing abundance of the native palm Chamaeropshumilis). Prehistoric land-use phases after the Bronze Age seem synchronous with those at other sites insouthern and central Europe, possibly as a result of climatic forcing. Considering the response of vegetationto Holocene climatic variability as well as human impact we conclude that under (semi-)naturalconditions evergreen broadleaved Q. ilex–O. europaea (s.l.) forests would still dominate near Gorgo Basso.However, forecasted climate change and aridification may lead to a situation similar to that before7000 cal yr BP and thus trigger a rapid collapse of the few relict evergreen broadleaved woodlands incoastal Sicily and elsewhere in the southern Mediterranean region.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2008|