8,000 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, we present a new sedimentary record covering the past ~ 8,000 years from Lago di Baratz, north-west Sardinia. Vegetation and fire history are reconstructed by pollen, spores, macrofossils and charcoal analyses and environmental dynamics by high-resolution element geochemistry together with pigment analyses. During the period 8,100-7,500 cal bp, when seasonality was high and fire and erosion were frequent, and woodlands dominated the coastal landscape. Subsequently, between 7,500 and 5,500 cal bp, seasonality gradually declined and thermo-mediterranean woodlands with and partially replaced communities under diminished incidence of fire. After 5,500 cal bp, evergreen oak 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. and ) around 5,000-4,500 cal bp. Subsequently around 4,000-3,500 cal bp evergreen oak-olive forests expanded massively when fire activity declined and lake productivity and anoxia reached Holocene maxima. Land-use activities during the past 4,000 years (since the Bronze Age) gradually disrupted coastal forests, but relict stands persisted under rather stable environmental conditions until ca. 200 cal bp, when agricultural activities intensified and and were planted to stabilize the sand dunes. Pervasive prehistoric land-use activities since at least the Bronze Age Nuraghi period included the cultivation of , and after 3,500-3,300 cal bp, and after 2,500 cal bp. We conclude that restoring less flammable native and forest communities would markedly reduce fire risk and erodibility compared to recent forest plantations with flammable non-native trees (e.g. , ) and xerophytic shrubland (e.g. , ).