The Lateglacial and Holocene vegetation and climate history of Lago di Mezzano (central Italy)

Abstract

The top 12 m of a lacustrine sediment sequence from Lago di Mezzano (42°36′N, 11°46′E, 452 a.s.l., Latium, central Italy) have been palynologically investigated. The chronology was established on the basis of radiocarbon dates, measures of annual laminations and volcanic ashes. The continuous sequence provides new fundamental information on the Lateglacial and Holocene, periods often fragmented in Italian pollen records, identifying vegetation dynamics and climate changes occurring in the last 15,300 years. The record starts at the end of the last glacial, closely following the climate changes found at a global scale, with clear stadial and interstadial oscillations, and evidence of cold/dry and wet/warm climatic changes. The Holocene is mostly characterized by forests, evolving rapidly to mature mixed deciduous oak (starting from 11,000 years BP) and, passing through beech forests (starting from ca. 9000 years BP) and alder carrs (starting from ca. 7000 years) to the deeply human-modified present-day landscape.Evaluating the importance of the local and regional human impact is not straightforward. A peculiarity of Lago di Mezzano, as of other Mediterranean lacustrine sites, is that it behaves at times as an “on-site” locale, when human populations were immediately by the lake, and at times as an “off-site” when settlements were found further away. This pattern changed according to cultural and climatic variations, both correlated to the water level of the lake.