8000 years of climate, vegetation, fire and land-use dynamics in the thermo-mediterranean vegetation belt of northern Sardinia (Italy).

Knowledge about the vegetation history of Sardinia, the second largest island of the Mediterranean, is scanty. Here, wepresent a new sedimentary record covering the past ~ 8,000 years from Lago di Baratz, north-west Sardinia. Vegetation andfire history are reconstructed by pollen, spores, macrofossils and charcoal analyses and environmental dynamics by highresolutionelement geochemistry together with pigment analyses. During the period 8,100-7,500 cal bp, when seasonalitywas high and fire and erosion were frequent, Erica arborea and E. scoparia woodlands dominated the coastal landscape.Subsequently, between 7,500 and 5,500 cal bp, seasonality gradually declined and thermo-mediterranean woodlands withPistacia and Quercus ilex partially replaced Erica communities under diminished incidence of fire. After 5,500 cal bp, evergreenoak forests expanded markedly, erosion declined and lake levels increased, likely in response to increasing (summer)moisture availability. Increased anthropogenic fire disturbance triggered shrubland expansions (e.g. Tamarix and Pistacia)around 5,000-4,500 cal bp. Subsequently around 4,000-3,500 cal bp evergreen oak-olive forests expanded massively whenfire activity declined and lake productivity and anoxia reached Holocene maxima. Land-use activities during the past4,000 years (since the Bronze Age) gradually disrupted coastal forests, but relict stands persisted under rather stable environmentalconditions until ca. 200 cal bp, when agricultural activities intensified and Pinus and Eucalyptus were planted tostabilize the sand dunes. Pervasive prehistoric land-use activities since at least the Bronze Age Nuraghi period included thecultivation of Prunus, Olea europaea and Juglans regia after 3,500-3,300 cal bp, and Quercus suber after 2,500 cal bp. Weconclude that restoring less flammable native Q. ilex and O. europaea forest communities would markedly reduce fire riskand erodibility compared to recent forest plantations with flammable non-native trees (e.g. Pinus, Eucalyptus) and xerophyticshrubland (e.g. Cistus, Erica).