Lago di Vico, central Italy. A detailed late Holocene pollen record

Lago di Vico is a volcanic lake located 50 km northwest of Rome, 40 km from the Tyrrhenian Sea, in central Italy. It has a max. depth of 50 m, an elevation of 510 m a.s.l., a diameter of ca. 5 km, a surface of ca. 12 km2, and a catchment area of ca. 40 km2. It is located in the central collapse caldera of the Vico volcanic district. The catchment, exclusively formed by volcanic rocks, is delimited by the edge of the caldera, peaking 965 m a.s.l. at Monte Fogliano where an estimate of the rainfall provided a value of about 2000 mm. Outside the caldera, at the closest meteorological station of Ronciglione (441 m a.s.l.), the mean annual precipitation (over 40 years) is about 1400 mm and the mean annual temperature is 13.6°C. The forest vegetation of the caldera is organized in belts: on the top of Monte Fogliano beech woods are found, while mixed forest of beech and deciduous oaks mainly lie on the southern and western slopes and on Monte Venere; on the northern slopes of the caldera mixed oak woods dominate by Quercus cerris is found; chestnut and hazel coppices are found respectively on the eastern slopes and on the flat areas surrounding the lake; extrazonal populations of Q. ilex and other Mediterranean elements are found on rocky and sunny slopes. Human activity in the caldera is archaeologically documented by a votive cave on Monte Venere where a series of ten radiocarbon dates from 8000±160 B.P. to 4390±50 B.P. indicates a long-lasting frequentation of the cave. Evidence of Bronze Age occupations is found on the northern slope of Monte Venere and on Monte Fogliano. Remnants of Etruscan and Roman cultures are widespread in the area. Three pollen records from Lago di Vico have been published, the longest one spanning the last 90,000 years (1), two others covering shorter periods (2, 3; None of them has a complete pollen record for the Holocene). With the aim of reconstructing the vegetation, the climate and the fire history of the last millennia, we present integrated pollen, microcharcoal and NPP (non pollen palynomorphs) analyses of the top 5.60 m of a new 12 m long sediment record. The core was drilled in the north-western sector of the lake, at a water depth of ca. 19 m. The diagram spans the last ca. 4500 years, the chronology was established using four radiocarbon dates and the characterization of one tephra level. Deciduous oaks, beech, hornbeams characterized the environment around the lake. Even if clear signs of human presence are detected before, a strong human impact on vegetation is recorded around 2800 years ago, at the beginning of the Iron Age, with forest clearance and cultivation of olive, chestnut and walnut. Intensive cultivation of hazel, which today characterizes the landscape around the lake, is quite recent, dating back to the Modern Age.