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The endorheic nature of Lake Trasimeno in combination with its position in central Italy makes it a relevant site to better constrain spatial differences in Holocene climatic variability in the Mediterranean area. Herein, we present a high-resolution ostracod record from the Holocene section of an 8.59-m-long sedimentary core, which is compared with historical data to distinguish anthropogenic and climatic signals. The occurrence, abundance and vanishing of ostracod species are directly controlled by lake-level variations, which are in turn related to global and regional climatic changes (i.e. moisture variations). The total organic carbon content as well as observed lithological changes provide additional information about Lake Trasimeno's hydrological and trophic conditions in the past. Most important variations have been identified at ca. 10,000 cal. yr BP, when the lacustrine basin changed from a temporary to a permanent waterbody (from Sarsicypridopsis aculeata to Candona angulata association). The highest lake level and the total absence of ostracods occur at around 9000 cal. yr BP. The recorded humid phase persisted up to ca. 4200 cal yr BP since when a lake-level decreasing trend started and continued until the present day (Candona angulata, Cyprideis torosa and Darvinula stevensoni associations). The frequency of changes in the relative abundance of the main species shows centennial variations (i.e. C. angulata, C. torosa and Darvinula stevensoni). As historical evidences yield that human interventions to control the lake level remained unsuccessful in the past, Lake Trasimeno records an almost pristine climatic signal during most of the Holocene, which is quite unusual in the highly populated Mediterranean area. [ABSTRACT FROM AUTHOR]

A multiproxy approach in a sediment core from Lake Trasimeno has been used to reconstruct the climate history of central Italy during the Late Pleistocene to Early Holocene period (ca. 47,000–9,000 cal yr B.P.). Ostracod assemblages and sedimentological data (lithology and carbonate content) have been used to infer past hydrological changes in the area. Ostracods were analyzed throughout the core using diversity indexes and multivariate statistic analyses (Cluster and PCA). Three main associations linked to lake level and salinity variations were recognized: 1) the C. torosa association, indicating permanent lacustrine conditions with high lake levels and low salinities; 2) the S. aculeata association, linked to very shallow/temporary waters with higher salinity conditions; and 3) the S. aculeata - E. mareotica association pointing to temporary water conditions and the highest salinities. Furthermore, the presence of C. fuscata and L. blankenbergensis during wide parts of the Late Pleistocene indicates temperatures lower than present days. Alternations of these three ostracod associations compares well with the oxygen isotope curve from Greenland (NGRIP) and are thus interpreted as climatically driven. At the Holocene transition (Termination 1), the ostracod associations indicate a delay in the increasing warming and humidity with respect to the NGRIP temperature record. [ABSTRACT FROM AUTHOR]